Estrogen biosynthesis and 1beta-hydroxylation using C19 and 19-nor steroid precursors.

(1) In order to study the relationship between aromatization (estrogen biosynthesis) and 1beta-hydroxylation, the effects of a variety of factors on these processes were evaluated. (2) Using the C18 substrate, 4-estrene-3,17-dione, it was found that carbon monoxide, SU-4885, amphenone B, potassium cyanide, 4-androstene-3,17-dione and 1,4-androstadiene-3,17-dione inhibited the above transformations significantly and to varying degrees. However, within a given experiment the inhibition of each process was similar. (3) SKF-525A did not inhibit either transformation. In addition, phosphate, Tris and barbital buffers, as well as pH changes from 6.9 to 7.7, had no stimulatory or inhibitory effect on the production of estrogen and 1beta-hydroxy compounds. (4) In contrast, several inhibitors affected the aromatization of C19 and C18 steroids differently. These include carbon monoxide, SU-4885 and amphenone B. (5) When a mixture of 4-[7beta-3Hi1estrene-3,17-dione and 19-[4-14C]nortestosterone were incubated together the former was preferentially converted to estrogen. This preference for the 17-keto steroidal form mimics results observed for C19 substrates. (6) We conclude that while estrogen biosynthesis and 1beta-hydroxylation appear to be mediated by the same enzyme system, the same conclusion cannot be drawn for the aromatization of C19 and C18 substrates.

PIP: Estrogen biosynthesis and lbeta-hydroxylation using carbon-19 and 19-nor steroid precursors were evaluated. 4-estrene-3, 17-dione was used to find that carbon monoxide, SU-4885, amphenone B, potassium cyanide, 4-androstene-3,17-dione, and 1,4-androstadiene-3,17-dione inhibited the above transformations to varying degrees. SKF-525A did not inhibit either transformation, and phosphate, Tris and barbital buffers as well as pH changes from 6.9 to 7.7 had no effect on the production of estrogen and lbeta-hydroxy compounds. Carbon monoxide, SU-4885, and amphenone B affected the aromatization of carbon-19 and carbon-18 steroids differently. A mixture of 4 (7 beta-tritium) estrene-3,17-dione and 19-(4-carbon 14) nortestosterone incubated together resulted in the former preferentially converted to estrogen. It is concluded that while estrogen biosynthesis and lbeta-hydroxylation appear to be mediated by the same enzyme system, however, the same conclusion cannot be drawn for the aromatization of carbon-19 and carbon-18 substrates.

Interactions between oral contraceptives and other drugs.

PIP: There is increasing evidence from various types of studies that commonly prescribed drugs can interact with OCs (oral contraceptives), leading to a decreased contraceptive efficacy. Additionally, contraceptive steroids influence the response to the other drug therapies as well. Antituberculous drugs enhance metabolism of the estrogenic component of OCs, thus reducing the contraceptive effect. Other types of drugs which have been shown to interfere with the contraceptive effect of OCs are: anticonvulsant, antibiotic, and analgesic drugs. The effect of OCs on anticoagulant, antihypertensive, antidiabetic, and antidepressant drugs is also outlined. Tables and graphs illustrate some of these disadvantegeous drug interactions.^ieng

Neurotransmitter modulation of steroid action in target cells that mediate reproduction and reproductive behavior.

Two major functional interactions between steroid hormones and neurotransmitters are generally recognized. First, steroids affect neurotransmission, and second, through effects on hypothalamic peptides that regulate anterior pituitary function neurotransmitters affect steroid secretion. In recent years, evidence has accumulated which indicates that neurotransmitters can also affect steroid action within postsynaptic steroid target cells. We review evidence for this relationship in pineal, uterus and hypothalamus and propose that the modulation of target cell responsiveness to steroids is an important mechanism by which neurotransmitters affect steroid-dependent processes. The operation of such a mechanism provides a means for environmental, behavioral and emotional events to rapidly and selectively alter steroid effects on behavior and physiology.

The influence of progesterone on the conversion of 17-hydroxyprogesterone to testosterone in the mouse testis.

PIP: Tritiated-progesterone and 17-hydroxyprogesterone-carbon 14 were incubated with mouse testis homogenates obtained from adult Swiss mice. The distribution of each isotope in 17-hydroxyprogesterone, androstenodione and testosterone when the 2 precursors were present in various ratios were compared with the amounts when each precursor was present alone. Formation of the major compound in these experiments occurs by a series of sequential reactions: progesterone to 17-hydroxyprogesterone to androstenodione to testosterone, and the assumption is made that the sum of the products beyond a given enzymatic step equals the amount of a particular precursor undergoing that reaction. The presence of equal amounts of progesterone and 17-hydroxyprogesterone caused a small but significant reduction in 17-hydroxyprogesterone activity. The presence of added 17-hydroxyproesterone essentially did not affect the rate at which 17-hydroxyprogesterone or 17-oxy radical formed from progesterone, but the amount of C-19 steroids progressively decreased as progesterone concentration was raised above 2.5 nmales per ml. This was probably because of the close association of active sites of the 17-hydroxylase and lyase. The presence of progesterone markedly inhibited the rate of splitting of the added 17-hydroxyprogesterone. The inhibition was probably competitive as previously reported for rat testis. The results indicate that the active site of the 17-beta-dehydrogenase was not closely associated with the lyase. At higher levels of either precursor alone the 17-beta-dehydrogenase approached saturation, but the inhibition of lyase activity by progesterone left the 1-beta-dehydrogenase unsaturated and a higher proportion of the smaller amounts of androstenodione formed was converted to testesterone.^ieng

Delta5-androstenediol: kinetics of metabolism and binding to plasma proteins in normal men and women.

Using the constant fusion and single injection technique the metabolic clearance rates (mean +/- SEM) for delta5-androstene-3beta, 17beta-diol (delta5-idol) were measured for 19 normal men (1311 +/- 67 1/24 h) and 10 normal women (858 +/- 63 1/24 h). The constant infusion technique yielded values for the conversation ratios for the transformation of delta5-diol to several products: dehydroepiandrosterone (DHEA)/delta5-diol of 0.06+/-0.01 for men and 0.05 +/- 0.01 for women, of delta5-diol sulfate/delta5-diol of 0.45 +/- 0.04 for men and 0.52 +/- 0.03 for women and of DHEA sulfate/delta5-diol of 5.53 +/- 0.26 for men and 5.02 +/- 0.42 for women. The single injection technique yielded rate constants (units) and volumes of distribution (liters) for delta5-diol; Ki = 34.3 +/- 4.3 for men and 35.0 +/- 3.9 for women, K2 = 63.7 +/- 4.1 for men and 75.1 +/- 4.2 for women, V1 = 23.1 +/- 3.2 for men and 11.9 +/- 2.3 for women, V2 = 14.8 +/- 3.7 for men and 9.2 +/- 3.2 for women. The mean delta5-diol plasma concentration was 1.08 +/- 0.10 ng/ml for 12 men and 1.17 +/- 0.16 ng/ml for 9 women. (he calculated blood production rates for delta5-diol were 1357 +/- 117 mug/24 h for 12 men and 969 +/- 131 mug/24 h for 9 women. The per cent binding (equilibrium dialysis) was higher for women (94.9 +/- 0.3) than for men (93.0 +/- 0.2). Paper electrophoresis showed that significant fractions of 3H-delta5-diol migrated with both the beta-globulin and albumin fractions. Estrogen administration to two normal men increased the per cent binding of delta5-diol to plasma proteins and decreased the metabolic clearance rate towards the values found for normal women.

PIP: Studies on the kinetics of delta 5-androstene-3beta,17beta-diol (delta 5-diol) metabolism and on the binding of delta 5-diol to plasma proteins in normal men and women are reported. Using the constant infusion and single injection technique the mean metabolic clearance rate for delta 5-diol was found to be 1311 1/24 hours in 19 normal men and 858 1/24 hours in 10 normal women (p less than .01). The constant infusion technique yielded values for the conversion ratios for the transformation of delta 5-diol to dehydroepiandrosteroe (DHEA)/delta 5-diol of .06 for men and .05 for women, of delta 5-diol sulfate/delta 5-diol .45 for men and .52 for women. The single injection technique yeilded rate constants (units=K) and volumes of distribution (liters) for delta 5-diol as K1=34.3 for men and 35 for women, K2-63.7 for men and 75.1 for women, V1=23.2 for men and 11.9 for women, V2-14.8 for men and 9.2 for women. mean delta 5-diol concentration was 1.08 and 1.17 ng/ml for 12 men and 9 women, respectively, while blood production rates were 1357 and 969 mcg/24 hours, respectively. Using equilibrium dialysis, the binding was 93 for men and 94.9 for women (p less than .01). Paper electrophoresis revealed significantly (p less than .01) more tritiated delta 5-diol associated with the beta-globulin area for women than for men. Estrogen administration to 2 normal men increased the percent binding of delta 5-diol to plasma proteins and decreased the metabolic clearance rate.

The new steroid analog RU 486 inhibits glucocorticoid action in man.

RU 486 [17 beta-hydroxy-11 beta-(4- dimethylaminophenyl )-17 alpha-(prop-1- ynyl )-estra-4,9-dien-3-one] is a new steroid analog which antagonizes glucocorticoid action at the receptor level in animals. To assess its potential antiglucocorticoid activity in man we studied the pituitary-adrenal response to RU 486 in normal men. The compound was administered at 0200 h and plasma cortisol and lipotropins (LPH) were measured hourly for 10 h. After 400 mg RU 486 significant and sustained elevation of both hormones occurred during the 0700-1200 h period: mean (+/- SE) plasma levels after placebo or RU 486 during this interval were, respectively, for cortisol (ng/ml), 63.4 +/- 8.2 and 112.7 +/- 2.9 (P less than 0.02); and for LPH (pg/ml), 34.8 +/- 11.3 and 71.6 +/- 15.4 (P less than 0.01). The 200- and 100-mg doses induced only transient cortisol and LPH increases. Administration of RU 486 (400 mg) at 1400 h induced no increase in plasma cortisol compared to placebo in the corresponding 2000 to 2400 h period. When RU 486 was administered concomitantly with dexamethasone (1 mg) at 2400 h, dose-dependent blockade of the dexamethasone-induced cortisol suppression at 0900 h was found (r = 0.62, P less than 0.01); this blockade was partial after the 100-mg dose, but complete after the 400-mg dose. Plasma LPH and ACTH showed parallel variations. We conclude that RU 486 antagonizes the negative pituitary feedback of both the nocturnal endogenous cortisol rise and exogenously administered dexamethasone. These actions are consistent with an antiglucocorticoid activity of this compound in man.

The antiglucocorticoid and antiprogestin steroid RU 486 suppresses the adrenocorticotropin response to ovine corticotropin releasing hormone in man.

The glucocorticoid and progesterone antagonist RU 486 normalizes the clinical and biochemical features of hypercortisolism in patients with nonpituitary Cushing's syndrome, presumably by antagonizing the action(s) of cortisol. Since RU 486 has progesterone agonist activity in addition to its progesterone antagonist action, the possibility that it might have some glucocorticoid agonist action did not seem unreasonable. To test this hypothesis we examined the effects of RU 486 on pituitary ACTH secretion in 10 patients with primary adrenal insufficiency in whom glucocorticoid replacement was withheld for 36 h. Each patient received, in randomized sequence 3-7 days apart, an oral dose of placebo, RU 486 (20 mg/kg), cortisol (0.1 mg/kg), or a combination of RU 486 and cortisol at 1800 h. Two hours later, an iv bolus dose of ovine CRH (1 microgram/kg) was administered, and plasma ACTH levels were measured serially for 3 h. RU 486 suppressed ovine CRH-stimulated ACTH secretion, albeit less than cortisol. Its glucocorticoid agonist effect was calculated to be approximately 1/250th that of cortisol on a weight basis. Additionally, RU 486 partially antagonized cortisol-induced suppression of ACTH secretion. These findings suggest that RU 486 is a partial glucocorticoid agonist and offer some insight as to its action in patients with Cushing's syndrome. Whether this degree of glucocorticoid agonist activity is adequate to support life, however, is not known.

PIP: The purpose of this study was to assess the glucocorticoid agonist activity of the antiprogestin steroid RU-486 by examining its ability to exert a glucocorticoid-like negative feedback effect on pituitary adrenocorticotropic hormone secretion. 10 patients with nonpituitary Cushing's syndrome, from whom cortisol therapy had been withheld for 36 hours, were given an oral dose of either a placebo, cortisol, or 20mg/kg of RU-480. 2 hours later, they were given an intravenous injection of lug/Kg of ovine corticotropin-releasing hormone. Blood samples were taken 15 minutes before the injection, at the time of the injection, and 15, 30, 60, 90, 120, and 180 minutes afterwards to measure adrenocorticotropic hormone and cortisol levels. Blood samples from the patients who received the RU-486 showed that RU-486 had suppressed the ovine corticotropin-releasing hormone-stimulated secretion of adrenocorticotropic hormone. However, the RU-486-induced suppression of the secretion of adrenocorticotropic hormone was only 80% that of the suppression induced by .1 mg/kg of cortisol, i.e., RU-486 had only 1/250 the glucocorticoid agonist effect of cortisol. RU-486, therefore, is a partial glucocorticoid agonist, but the effect is not of sufficient magnitude to prevent adrenal insufficiency in patients with nonpituitary Cushing's syndrome.

Administration of RU 486 for 8 days in normal volunteers: antiglucocorticoid effect with no evidence of peripheral cortisol deprivation.

New therapeutic indications based on the antiprogesterone action of RU 486 (Mifepristone) are emerging which require long term administration and raise the question of its safety because of the antiglucocorticoid action of the drug. A trial was designed to assess the antiglucocorticoid effect of RU 486, possible manifestations of peripheral cortisol deprivation, and the adrenocortical and corticotroph reserves. Ten normal male volunteers (aged 21-29 yr) were given RU 486 (200 mg/day) or placebo between 0800-0900 h for 8 consecutive days in a randomized, double blind, cross-over design, with a 1-month interval between the two periods. RU 486 induced overactivation of the pituitary-adrenal axis; baseline values (mean +/- SEM) before and at end of treatment were, respectively: 0800 h plasma cortisol, 147.3 +/- 15.5 and 257.6 +/- 8.8 ng/mL; 0800 h salivary cortisol, 5.8 +/- 1.2 and 15.2 +/- 0.8 ng/mL; nocturnal (2200-0800 h) urinary cortisol, 8.4 +/- 1.5 and 33.7 +/- 11.1 micrograms; and 0800 h plasma ACTH, 29.2 +/- 3.7 and 60.2 +/- 8.4 pg/mL. All of these variations were significantly different from those during placebo treatment (0.0001 < P < 0.03) and disappeared within 4 days after the end of treatment. A daily record of subjective clinical symptoms, body weight and temperature, blood pressure, and heart rate showed neither side-effects nor any significant variation during treatment. Blood electrolyte and eosinophil counts were unchanged; fasting blood glucose was slightly higher at the end of treatment (5.0 +/- 0.2 vs. 4.7 +/- 0.1 mmol/L; P = 0.04). The adrenocortical response to Cortrosyn (0.25 mg, im) was exaggerated during RU 486 treatment (P < 0.006): peak values before and at the end of treatment were, respectively: plasma cortisol, 272.5 +/- 15.2 and 347.1 +/- 20.6 ng/mL; and salivary cortisol, 17.0 +/- 2.2 and 31.1 +/- 3.1 ng/mL. Direct pituitary stimulation (100 micrograms ovine CRH, followed by 1 IU lysine vasopressin over 15 min) also induced exaggerated corticotroph and adrenocortical responses (P < 0.005); peak values before and at the end of treatment were, respectively: plasma ACTH, 147.7 +/- 24.6 and 254.0 +/- 41.3 pg/mL; and plasma cortisol, 231.6 +/- 7.3 and 319.2 +/- 12.3 ng/mL. These data show that 8-day treatment with 200 mg RU 486 daily induces a hormonally detectable antiglucocorticoid effect without clinical symptoms. This state results from reversible cortisol overproduction with preservation of adrenocortical and pituitary reserves.

PIP: At Cochin Hospital in Paris, France, ten 21-29 year old normal male volunteers received either 200 mg RU-486 per day or a placebo for 8 consecutive days between 8:00 and 9:00 in the morning, then went through a 28-day washout period before receiving what they did not receive the first time for 8 days. The researchers wanted to examine the antiglucocorticoid effect of RU-486, any evidence of peripheral cortisol deprivation, and the adrenocortical and corticotroph reserves. An assessment of potential risk of longterm administration of RU-486 is needed to determine whether it can be used to treat chronic diseases (e.g., meningioma and breast cancer). RU-486 was responsible for overreaction of the pituitary-adrenal axis (8:00 am plasma cortisol, 147.3 ng/mL vs. 257.6 ng/mL; 8:00 am salivary cortisol, 5.8 ng/mL vs. 15.2 ng/mL; nocturnal urinary cortisol, 8.4 mcg vs. 33.7 mcg; and 8:00 am plasma adrenocorticotropic hormone [ACTH] 29.2 pg/mL vs. 60.2 pg/mL). All these changes differed significantly from those during placebo treatment (0.0001 p 0.03). These changes no longer existed 4 days after the end of treatment. The men kept a daily record of subjective clinical symptoms, body weight and temperature, blood pressure, and heart rate, which did not indicate any side effects or any considerable variation during treatment. RU-486 did not affect blood electrolyte and eosinophil counts. Blood glucose levels during fasting were somewhat higher at the end of treatment (p = 0.04). During RU-486 treatment, the adrenocortical response to 0.25 mg of intramuscularly injected Cortrosyn was amplified (peak values before and after, plasma cortisol, 272.5 ng/mL vs. 347.1 ng/mL; 17 ng/mL vs. 31.1 ng/mL) (p 0.006). Direct stimulation of the pituitary resulted in exaggerated corticotroph and adrenocortical responses (p 0.005). These findings showed that a daily dose of 200 mg RU-486 causes a hormonally detectable antiglucocorticoid effect but no clinical symptoms.

Inhibition of testosterone metabolism in the human prostate.

PIP: The conversion of carbon-14-testosterone (T) to 5alpha-dihydrotestosterone (DHT) and androstanediol (A-diol) was studied in vitro using a crude homogenate of prostate from patients with benign prostatic hypertrophy. Under standard conditions, the mean conversion to DHT was 70 + or -1 (standare error, SE)% and to A-diol 14 + or -1 (SE)%. Addition of various antiandrogens and other substances decreased the T to DHT conversion to 0-55% and the T to A-diol to 0-10%. The most potent inhibitors were desoxycorticosterone and progesterone. Estradiol-17beta, cyproterone acetate, medrogestone, medroxyprogesterone acetate, estriol and 4'-nitro-3'trifluoromethylisobutyramilide were also effective inhibotors. To determine whether this effect might be significant in vivo, similar conversion studies were carried out on prostatic tissue obtained from 3 patients who had received oral medrogestone for 1-2 weeks. T to DHT was reduced to 12.2 + or -2.8 (SE)% and T to A-diol to 6.5 + or -1.0 (SE)%. The ability of such compounds to inhibit DHT formation represents 1 mode of action which may account at least in part for their efficacy in the treatment of benign prostatic hypertrophy.^ieng

Prednisolone disposition and protein binding in oral contraceptive users.

Combined estrogen-progestogen oral contraceptives (OC) have been shown to alter the metabolism of certain drugs, including corticosteroids, as well as affect circulating protein concentrations. To assess these effects with regard to prednisolone, the pharmacokinetics and protein binding of this steroid were evaluated in eight female OC users and compared with results from eight male and five female non-OC users. All volunteers received 40 mg prednisolone, iv, and steroid concentrations were measured by high pressure liquid chromatography. Plasma clearance of total prednisolone in females on OC was 96 +/- 9 (SD) ml/min X 1.73 m2, significantly (P less than 0.001) lower than those in both male and female controls (205 +/- 46 and 187 +/- 22 ml/min X 1.73 m2). The prednisolone half-life and mean residence time were longer, while the steady state volume of distribution was smaller for OC users. Unbound prednisolone was measured by equilibrium dialysis, and pharmacokinetic and protein binding parameters were calculated from free prednisolone concentrations. A significantly higher (2-fold) concentration of transcortin was found in OC users. Evaluation of free prednisolone parameters showed a significantly lower clearance and decreased volume of distribution, without alteration of the mean residence time for the OC users. Dual OC effects on binding and elimination of prednisolone occur with the net result of a 2-fold increase in the area under the free concentration-time curve, indicative of a marked reduction in the biotransformation rate of the steroid.

Effects of oral contraceptive steroids on acetaminophen metabolism and elimination.

Plasma acetaminophen elimination was examined in women taking low-dose estrogen oral contraceptive (OC) steroids and in age-matched control women. Fractional rates of elimination and fractional clearances were calculated for each of the metabolic pathways, including oxidation, sulfation, and glucuronidation. The cysteine adduct and mercapturic acid derivative of acetaminophen were used as an index of oxidative biotransformation, a potentially toxic route of metabolism for acetaminophen. Plasma acetaminophen clearance rose from 287 +/- 13 ml/min to 470 +/- 51 ml/min in women taking OC steroids, whereas elimination t1/2 decreased from 2.40 +/- 0.14 hr to 1.67 +/- 0.16 hr. The fractional clearance and rate of elimination of acetaminophen by glucuronidation increased in women taking OC steroids, whereas the clearance and elimination by sulfation did not differ significantly from values in control subjects. Fractional clearance of the cysteine adduct also increased significantly, but clearance of acetaminophen mercapturic acid did not change. These data suggest that the increased clearance of acetaminophen from plasma in women taking OC steroids results from increased glucuronidation of the drug, although the mechanism is not known.

PIP: Plasma acetaminophen elimination was examined in women taking low-dose oral contraceptives (OCs) and in age-matched control women. Fractional rates of elimination and fractional clearances were calculated for each of the metabolic pathways, including oxidation, sulfation, and glucuronidation. The cysteine adduct and mercapturic acid derivative of acetaminophen were used as an index of oxidative biotransformation, a potentially toxic route of metabolism for acetaminophen. Plasma acetaminophen clearance rose from 287 +or- 13 ml/minute to 470 +or- 51 ml/minute in women taking OCs, whereas elimination t1/2 decreased from 2.40 +or- 0.14 hours to 1.67 +or- 0.16 hours. The fractional clearance and rate of elimination of acetaminophen by glucuronidation increased in women taking OCs, whereas the clearance and elimination by sulfation did not differ significantly from values in control subjects. Fractional clearance of the cysteine adduct also increased significantly, but clearance of acetaminophen mercapturic acid did not change. These data suggest that the increased clearance of acetaminophen from plasma in women taking OCs results from increased glucuronidation of the drug, although the mechanism is not known.

Enzyme induction by oral testosterone.

Six normal male volunteers ingested a dose of 400 mg free testosterone daily as tablets over 21 days. By the end of treatment intravenous antipyrine half-life had decreased significantly from 8.0 +/- 2.7 to 5.7 +/- 2.6 hr. The subjects eliminated testosterone from serum more rapidly on the twenty-first day of testosterone ingestion than on the first day. Serum albumin, bilirubin, prothrombin, alanine-amino-transferase, and alkaline phosphatases were unchanged during the experiment. It is concluded that oral testosterone treatment induces the hepatic drug-metabolizing system including that of testosterone.

PIP: The effects of high doses of testosterone on liver function was studied in 6 healthy males. Intravenous antipyrine elimination was used as the primary parameter of liver function. The subjects received 400 mg testosterone orally for 20 days. The half-life of antipyrine decreased from a mean of 8 + or -2.7 to 5.7 + or -2.6 hours by the end of treatment. Excretion of testosterone was significantly (p greater than .0005) higher on Day 21 of the experiment than on Day 1. Treatment had no apparent effect on serum levels of albumin, bilirubin, prothrombin, alanine-amino-transferase, and alkaline phosphatases. It is concluded that orally administered testosterone induces its own enzymatic metabolism.

Impairment of antipyrine metabolism by low-dose oral contraceptive steroids.

The effect of low-dose oral contraceptive steroids (OCS) on the kinetics of intravenous antipyrine was determined. Eight women (age, 23.1 +/- 1.1 yr (mean +/- SE); weight, 57.8 +/- 2.2 kg) using low-dose (less than or equal to 50 micrograms) estrogen oral contraceptive steroids (OCS) on a long-term basis were age- and weight-matched with eight controls (age, 23.4 +/- 0.8 yr; weight, 58.4 +/- 2.1 kg) not using OCS. All were nonsmokers taking no other drugs. OCS subjects had a longer antipyrine elimination half-life (t1/2 beta) than the controls (17.3 +/- 1.6 and 10.5 +/- 0.8 hr; p less than 0.005). Volume of distribution was similar for both groups (0.59 +/- 0.02 l/kg [OCS] and 0.58 +/- 0.02 l/kg). Total metabolic clearance of antipyrine was slowed in OCS subjects (0.41 +/- 0.03 and 0.66 +/- 0.05 ml/min/kg; p less than 0.001). Since volume of distribution and body weight are of the same order in both groups, prolongation of antipyrine t1/2 beta is the result of decreased total metabolic clearance. Thus, even low-dose estrogen containing OCS may impair clearance of other drugs.

PIP: The effects of low-dose oral contraceptives (Ortho-Novum 1/50, Norinyl 1/50, Zorane 1.5/30, Lo/Ovral, and Modicon) on the kinetics of intravenous antipyrine were studied because of its indications of liver microsomal enzyme alterations. 8 healthy nonsmoking women aged 20-26 years, taking the pills for more than 3 months, were studied. They were compared with 8 matched noncontraceptive using controls. Kinetic variables were similar in the case and control groups; these variables incluced initial distribution, half-life, apparent central compartment volume, and total apparent volume of distribution. However, mean clearance was much lower in the cases (.41 and .66 ml per minute per kgm; P.001). This difference in clearance resulted in prologation of the elimination half-life (17.3 and 10.5 hours; P.005) in users. Since volume of distribution and body weight were on the same order in both groups, prologation of antipyrine elimination half-life must result from decreased total metabolic clearance, implying that even low-dose estrogen-containing oral contraceptives may impair clearance of other drugs.

Oral contraceptive effects on methylprednisolone pharmacokinetics and pharmacodynamics.

OBJECTIVE: Oral contraceptive (OC) steroids alter the disposition of numerous drugs, including corticosteroids. We investigated the pharmacokinetics and pharmacodynamics of methylprednisolone. METHODS: Twelve women (six women used OC steroids and six women did not) received intravenous methylprednisolone (0.6 mg/kg ideal body weight). Methylprednisolone disposition was assessed from plasma concentrations. Pharmacodynamic parameters measured were plasma cortisol, whole blood histamine (reflecting basophils), and blood helper T lymphocytes. RESULTS: Methylprednisolone clearance was significantly decreased in the women who used OC steroids (0.298 versus 0.447 L/hr/kg), resulting in a longer elimination half-life (2.20 versus 1.72 hours). With use of indirect response models, significant differences were observed with the cortisol and basophil responses. A larger value for the concentration that inhibits the zero-order production rate by 50% (0.37 versus 0.11 ng/ml) was observed in the women who used OC steroids for suppression of cortisol secretion, indicating less sensitivity to the suppressive effects of methylprednisolone. Greater net suppression of basophils was observed in the users of OC steroids (area under the response curve, 694 versus 401 ng x hr/ml). No differences were observed for helper T-cell responses. CONCLUSION: OC steroids appear to inhibit methylprednisolone metabolism. However, mixed changes in several responses occur, indicating that women can probably receive similar doses of methylprednisolone irrespective of OC steroid use.

PIP: At the Buffalo General Hospital in New York, researchers randomly assigned 6 healthy, nonobese women, 30-36 years old and using a triphasic oral contraceptive (OC) (Triphasil 28, Wyeth-Ayerst Laboratories), to either the baseline phase group or the group receiving an intravenous bolus of methylprednisolone sodium succinate at a dose of 0.6 mg/kg ideal body weight during the 2-week period after ovulation (i.e., luteal phase). These women were compared with 6 other women who did not use OCs but did receive the same dose of methylprednisolone. The purpose was to determine whether the adrenosuppressive, anti-inflammatory, and immunosuppressive effects of methylprednisolone differ in OC users. OC users experienced slower clearance of methylprednisolone (33% slower) than controls. This slower clearance rate contributed to a longer elimination half-life for methylprednisolone (2.2 vs. 1.72 hours; p 0.05). OC users also had a rate of slower elimination of cortisol than controls (0.180 vs. 0.276 hr-1; p 0.05). They had higher mean cortisol levels than controls (136 vs. 65 ng/ml). Women who used OCs for suppression of cortisol secretion had a larger value for the concentration of cortisol that suppresses the zero-order production rate by 50% (0.37 vs. 0.11 ng/ml; p 0.05), suggesting a decreased sensitivity to the effects of methylprednisolone on cortisol suppression. OC users experienced a greater net suppression of basophils at drug effect than at baseline. Methylprednisolone appeared to have no effect on helper T-cell responses. These findings suggest that OCs inhibit methylprednisolone metabolism. Since there were inconsistent changes in several responses, women can likely receive similar doses of methylprednisolone irrespective of OC use.

Biochemical, endocrine, and other indices during quinestrol therapy.

PIP: The effect of .025 mg quinestrol twice daily for 6 months was studied in 8 menopausal and postmenopausal women. There was no change in mean body weight, blood pressure readings, pulse rate or electrocardiograms. Vaginal smears showed an estrogenic effect of the drug which included cornification of the vaginal epithelium. There was a slight decrease in beta lipoproteincholesterol and serum acid phosphatase. There was an increase in serum creatine between the third and sixth months of treatment with no change in serum creatinine. In non-diabetic women, glucose-induced hypophosphatemia was accentuated. In diabetic women, the glucose tolerance appeared to improve. In both groups, increases in serum insulin caused by a glucose load were less under quinestrol therapy than without.^ieng

Disposition of chlordiazepoxide: sex differences and effects of oral contraceptives.

There is considerable interspecies and interdrug variability in the effect of sex differences and oral contraceptive (OC) steroids on hepatic drug elimination. Their influence on the disposition of chlordiazepoxide has been studied in 11 healthy young men (29 +/- 5 yr), 11 healthy young women (28 +/- 5 yr), and 7 healthy women receiving OC steroids (27 +/- 2 yr) for more than 6 months. The elimination half-life (t1/2(beta)) was longer (from 14.8 +/- 5.9 hr to 8.9 +/- 2.5 hr) and protein binding less (95.5 +/- 1.4% and 97.0 +/- 1.2%) in women than in men. Weight-normalized plasma clearances of total drug did not differ, but the clearance of unbound drug was significantly less in women (8.7 +/- 5.0 ml/min/kg) than in men (15.6 +/- 5.3 ml/min/kg). Women on OC steroids had a lower plasma binding (from 93.6 +/- 1.5% to 95.5 +/- 1.4%) and a higher volume of distribution (from 0.62 +-/ 0.23 l/kg to 0.40 +/- 0.14 l/kg) than women not on OC steroids. The elimination t1/2 was longer (from 24.3 +/- 12 hr to 14.8 +/- 5.9 hr) and the clearance of unbound drug lower (from 5.7 +/- 3.0 ml/min/kg to 8.7 +/- 5.0 ml/min/kg) in women on OC steroids than in those not using them, but these differences were not statistically significant.

PIP: The effect of oral contraceptives (OCs) on hepatic drug elimination, in this case chlordiazepoxide, was studied in 11 healthy young men, 11 healthy young women, and 7 healthy young women receiving OCs for more than 6 months. Elimination half-life was longer (14.8-8.9 hours) and the protein binding less (95.5 and 97%) in women than in men. When weights were normalized, plasma clearances of total drug did not differ, but clearance of unbound drug was significantly less in women (8.7 ml/min/kg) than in men (15.6 ml/min/kg). Women taking OCs had a lower plasma binding (from 93.6-95.5%) and a higher volume of distribution (from .62-4 1/kg) than women not taking OCs. Elimination half-life was longer (from 23.4-14.8 hours) and clearance of unbound drug lower (from 5.7-8.7 ml/min/kg) in women on OCs than in those not using them, but these differences were not statistically significant.

Vitamin B6 requirements of women using oral contraceptives.

Fifteen women who used combined estrogen-progestogen oral contraceptives and nine control women were given a vitamin B6-deficient diet for 4 weeks and the same diet supplemented with 0.8, 2.0, or 20.0 mg of pyridoxine hydrochloride for an additional 4 weeks. At weekly intervals a variety of indices of vitamin B6 nutrition were measured to determine rates of depletion and repletion. The tryptophan load test (2.0 g) was significantly different in the contraceptive users. However, other indices, including urinary cystathionine (3.0 g L-methionine load), urinary 4-pyridoxic acid, plasma phosphate, and erythrocyte alanine and aspartate aminotransferases, were not significantly different. Since altered tryptophan metabolism persisted in contraceptive users even when other indices of vitamin B6 nutrition were normal, we suggest that the use of oral contraceptives specifically affects tryptophan metabolism by some means other than through a vitamin B6 deficiency.

PIP: This study was designed to evaluate the effect of oral contraceptive use on the requirement for Vitamin-B6 and the rate at which such persons became depleted of Vitamin-B6 while ingesting a diet low in this vitamin. The same indices were used to measure the rate at which these persons became repleted when the diet was supplemented by pyridoxine. Before testing, women using estrogen-containing oral contraceptives were shown to excrete increased amounts of tryptophan metabolites after a tryptophan load test as compared with women not taking oral contraceptives. Elevated levels of 3-hydroxyanthranilic acid were also excreted in urines of such subjects. There were 15 young women subjects who had used estrogen-progestogen oral contraceptives for at least 6 months and 9 women who had not used any oral contraceptive. All were given a Vitamin-B6 deficient diet containing only 1.9 mg of pyridoxine equivalent per day for 4 weeks and then the same diet supplemented with .8-20 mg of pyridoxine hydrochloride for 4 more weeks. Weekly indices of Vitamin-B6 nutrition were determined. Only the tryptophan load test was significantly different in contraceptive users. Urinary cystathionine, urinary 4-pyridoxic acid, plasma phosphate, erythrocyte alanine, and aspartate aminotransferases were not significantly changed. The altered tryptophan metabolism persisted in contraceptive users after other indices of Vitamin-B6 nutrition became normal. Therefore, this altered tryptophan metabolism in oral contraceptive users is considered to be due to other factors than Vitamin-B6 deficiency. This effect may be primarily dependent on the activity of tryptophan oxygenase although other enzymes may also be factors. It is suggested that the use of estrogen-containing oral contraceptives may produce a Vitamin-B6 deficiency in some persons but this is not considered consistent or to have been shown by these experiments. The amount of Vitamin-B6, as pyridoxine, needed to maintain normal levels of indices, other than tryptophan, was between .8 and 2 mg/day. Data suggest that any alteration of Vitamin-B6 need by the use of combined estrogen-progestogen preparations is a minor one of doubtful clinical significance in the majority of women taking these steroids.

Relationship between levels of blood lipids, vitamins C, A, and E, serum copper compounds, and urinary excretions of tryptophan metabolites in women taking oral contraceptive therapy.

To evaluate which women using oral contraceptive agents might be at risk, biochemical indices known to be affected by the estrogens and progestogens were studied in women who take oral contraceptive agents, in women who do not use oral contraceptive agents, in women in third trimester of pregnancy and 6 weeks after parturition, and in men with normal and high blood lipid levels. The most consistent changes due to oral contraceptive agents were in serum levels of copper, triglycerides, and vitamin A and in the urinary excretion of xanthurenic acid and niacin derivatives before and after a tryptophan load test. There was only a slight suggestion, with no statistical significance, that serum vitamin C levels decreased when the serum levels of ceruloplasmin were high. The highest blood pressures and serum triglycerides and vitamin A levels were obtained in those women who ingested the highest level of estrogens. Pregnant women had the lowest levels of serum vitamin A. The oral contraceptive agents users had the lowest average levels of carotenoids corresponding to the highest average levels of vitamin A in the serum. Thus, estrogens not only increase the rate of change of tryptophan to niacin but may also increase the rate of conversion of carotene to vitamin A. Relative reactivity to oral contraceptive agents and possible risk to a patient might be evaluated by a profile of blood pressure and serum triglycerides, copper, and vitamin A.

PIP: To determine if methods can be developed which will show those patients for whom oral contraceptive agents (OCAs) constitute a hazard, data on blood lipids, serum levels of Vitamis-A, E, and C and copper are reported. Results of the tryptophan load test are also given. This tes t is related to the levels of pyridoxine in the tissues. The program was designed to show the relationship of any changes to each other, and to get a better understanding of their significance. Results are compared from subjects taking OCAs, from those not taking OCAs, from women in the last trimester of pregnancy, from women after parturition, and from males. All blood and urine samples were taken at 21 days after the beginning of subjects' menstrual periods, except for those who were pregnant and males. There were 49 women taking a variety of OCAs. 32 not taking OCAs served as controls. Included were 22 pregnant women in the last trimesters of their pregnancies. Of these, 11 were tested again 6 weeks postpartum. 9 men with high blood lipids and 12 men with normal lipid levels were also tested. Diastolic blood pressures averaged higher in the group taking OCAs (p less than .01), except for the males who were older or who wer known to have high lipids. Serum cholesterol levels in OCA users were unaltered. Serum phospholipids showed some increase in OCA users (p less than .05). Triglycerides show ed the greatest increase in OCA users (p less than .001), especially in those taking the most estrogen. The pregnant women had high serum levels of cholesterol, triglycerides, phospholipids, and total lipids. All of these levels were found to be less at 6 weeks postpartum. Serum copper levels were increased in all OCA users to above 1.5 mcg/ml but in only 2 of the nonusers to this level. Serum Vitamin-A was increased in the OCA user group (p less than .001). The pregnant women had relatively low levels of Vitamin-A. This increased by 6 weeks after parturition to the level of OCA users. An 8-hour urine collection after a 2-g tryptophan load showed at 6 times increased excretion of xanthurenic acid in those using OCAs as compared with nonusers. An increased ability of pregnant women to convert tryptophan to nictionic acid was shown. It is not known to what degree the biological changes caused by OCAs are undesirable. However, it is assumed that women showing the greatest changes are at greater risk. Analyses which may serve as incicators of potential risk include serum triglycerides, copper, and Vitamin-A levels. Carbohydrate intolerance and triglyceride elevation have been associated. Blood pressure measurements should be included in any profile.

Oral contraceptives and ascorbic acid.

Plasma, leukocyte, and platelet ascorbic acid levels are decreased in women ingesting oral contraceptive steroids. Studies have shown that it is the estrogenic component of the oral contraceptive agents that is associated with the decresased ascorbic acid concentrations. Urinary excretion of ascorbic acid does not appear to be increased by the steroids. Although serum levels of copper are increased by estrogens and oral contraceptives, ascorbic acid catabolism does not appear to be increased (unpublished). Our preliminary data on tissue uptake of ascorbic acid suggest that changes in tissue distribution are one possible answer for the observed effects of the steroids on blood levels of ascorbic acid.

PIP: Plasma, leukocyte and platelet ascorbic acid levels have been shown to decrease in in women using oral contraceptives (OC). Supplemental ascorbic acid therapy ranging from 50-200 mg/day showed no difference between the values for supplemented and nonsupplemented OC use. Measurement of plasma ascorbic acid after supplementation with 500 mg ascorbic acid/day for 14 days showed that adequate supplementation to reach tissue saturation and maximum fasting plasma levels occurred in control subjects but not in OC users. Other studies indicated that when women were maintained for 75 days on high ascorbic acid intake, the plasma levels in OC users were lower than in controls. Studies in humans and animals suggest that the estrogen in OCs cause decreased plasma and tissue levels of ascorbic acid. Women taking oral progestin (.35 mg daily norethisterone) and depot progestin (150 mg medroxyprogesterone acetate im every 3 months) had similar leukocyte plasma and platelet levels of ascorbic acid to controls. 625 mg daily of conjugated estrogens showed lower plasma and leukocyte levels than controls. Whereas increase of urinary excretion of ascorbic acid during OC therapy has not been shown, an increase in serum copper levels has been shown under OC use and estrogen influence. It is suggested that an increased catabolism of ascorbic acid accounts for the decreased plasma and tissue levels in humans and animals with estrogen or OC steroids. Other unconfirmed or disputed suggestions include decreased absorption, changes in tissue distribution and decreased levels of reducing compounds. Tissue uptake patterns in steroid-treated animals appear altered suggesting that changes in tissue distribution may be associated with observed changes in ascorbic acid blood levels in OC users.

Effect of oral contraceptive agents on nutrients: II. Vitamins.

Clinical, biochemical and nutritional data were collected from a large population of women using oral contraceptive agents. Higher incidence of abnormal clinical signs related to malnutrition were observed in the lower (B) as compared to the higher (A) socioeconomic groups, and also in the nonsupplemented groups as compared to the supplemented groups in the B subjects. As a rule the intake of oral contraceptive agent subjects of vitamin A, C, B6 and folic acid did not differ from that of the controls As expected, subjects from the supplemented groups had higher intake of vitamin A, C, B6, thiamin, riboflavin and folic acid, and A groups had higher intake of vitamin C, B6, riboflavin and folic acid. Increased plasma vitamin A and decreased carotene levels were observed in oral contraceptive agent users. In general oral contraceptive agents had little or no effect on plasma ascorbic acid. Urinary excretion of both thiamin and riboflavin in subjects using oral contraceptive agents were lower in A groups. Erythrocyte folate and plasma pyridoxal phosphate was decreased in A groups due to oral contraceptive agents. Subjects who took supplements had higher levels of plasma vitamin A, ascorbic acid and folate. But urinary thiamin and riboflavin were higher only in group A subjects who took supplements.

PIP: 18-45 year old women were tested to determine if the use of oral contraceptive agents (OCAs) affects the metabolism of vitamins. 4 different hormonal conditions and 2 socioeconomic levels in 8 groups were considered. Some of each socioeconomic level had taken Norinyl (1 mg norethisterone and 50 mcg mestranol) for 3 months or more. Others had used Ovral (.5 mg norgestrel and 5 mcg ethinyl estradiol) for equal periods. There were some in each group who had resumed use of OCAs during lactation within 5 weeks after pregnancy. Vitamins and mineral supplements were given to groups in each socioeconomic classification. They had a higher intake of Vitamins-A, C, thiamin, riboflavin, and folic acid. Incidence of clinical sings of malnutrition, such as dry skin, easily pluckable hair, angular lesions of the mouth, dental caries, bleeding gums, glossitis, and scaling of the skin, were significantly more frequently observed in the lower socioeconomic groups, and especially in nonsupplemented groups of women taking OCAs than in others. OCA administration increased plasma Vitamin-A levels but no socioeconomic effect was found. Plasma carotene levels were decreased by OCA therapy, but less so in the higher socioeconomic subjects. Plasma ascorbate was not affected by OCA use. Urinary excretion of thiamin annd riboflavin was decreased in subjects using OCAs. Erythrocyte folate and plasma pyridoxal phosphate (PLP) were also decreased. Results show a definite lowering effect of OCAs on red cell folate in subjects in the upper socioeconomic levels. There may also be a depletion of body stores of folic acid. It has been suggested that women who become pregnant soon after discontinuing OCA therapy have a high chance of developing folic acid deficiency during pregnancy. The lower socioeconomic group may be marginally deficient in folic acid. Similar results were obtained with thiamin and riboflavin. Changes due to OCA use with respect to thiamin, riboflavin, folate, and PLP were seen mainly in subjects in the upper lower socioeconomic groups may have prevented detection of smaller similar alterations due to OCA use.