Effect of Cinnamomum cassia methanol extract and sildenafil on arginase and sexual function of young male Wistar rats.

INTRODUCTION: Herbs have been used as an aphrodisiac since ages. Cinnamomum cassia is an important ingredient of many Ayurvedic formulations to treat male sexual disorder including erectile dysfunction (ED). AIM: The objective of the present study was to evaluate erectogenic and aphrodisiac activity of methanol extract of C. cassia bark in young male rats. METHODS: Methanol extract of C. cassia was screened in vitro for arginase inhibition potential and IC50 was determined. Effect of the extract was observed in vitro on phenylephrine pre-contracted isolated rat corpus cavernosum smooth muscle (CCSM) at 0.1, 1, 10, and 100 µg/mL. Young male Wistar rats were dosed with extract at 100 mg/kg body weight for 28 days and its effects on sexual behavior and penile smooth muscle : collagen level were observed. MAIN OUTCOME MEASURE: Effect of C. cassia was studied on arginase activity in vitro and sexual behavior of young male rats. RESULTS: C. cassia inhibited arginase activity in vitro with an IC50 of 61.72 ± 2.20 µg/mL. The extract relaxed phenylephrine pre-contracted isolated rat CCSM up to 43% and significantly increased (P < 0.05) sexual function of young male rats. Treatment with the extract also increased smooth muscle level and decreased collagen level in rat penile tissue. CONCLUSION: The study proves usefulness of methanol extract of C. cassia bark for increasing sexual function.

Developmental changes in mitochondria during the transition into lactation in the mouse mammary gland. II. Membrane marker enzymes and membrane ultrastructure.

The activity of cytochrome oxidase (an inner mitochondrial membrane marker) in mouse mammary gland homogenates was found to increase five- to sixfold from late pregnancy to day 8 of lactation, while that of monoamine oxidase (an outer membrane marker) increased only about 25%. The specific activity of cytochrome oxidase in the isolated mitochondria decreased slightly over the same period while the specific activity of monoamine oxidase decreased fivefold. This reflects the fact that both cytochrome oxidase and mitochondrial protein are increasing at a much greater rate than is monoamine oxidase activity. Mixing experiments preclude the possibility that the release or removal of an inhibitor or stimulator produces the changes in enzymatic activity. The cytochrome oxidase to monoamine oxidase ratio was followed throughout the pregnancy-lactation cycle in total mammary homogenates, isolated mammary parenchymal cells, and isolated mammary mitochondria. In each preparation the pattern was the same with little change in the ratio until late pregnancy; and then a three- to fourfold increase occurred and the values reached a maximum by day 8 of lactation. These experiments were interpreted as demonstrating that the observed enzymatic changes are reflective of alterations in the mitochondria of the mammary parenchymal cell population. Electron micrographs of mid-pregnant and mid-lactating mammary parenchymal cells in situ were prepared, and distinct changes in the mitochondrial morphology noted. The most significant and obvious change is the large increase in the number of inner membrane cristae and an increase in matrix density in the lactating gland cell. Therefore, both enzymatic and morphological studies support the concept of an expansion of the mitochondrial inner membrane during presecretory differentiation in the mouse mammary parenchymal cell.

PIP: The enzyme markers for mitochondrial inner and outer membranes throughout the pregnancy-lactation cycle in the mouse were compared. The ultrastructural changes of the organelle during the transitions were studied by electron microscopy. The activity of cytochrome oxidase in mouse mammary gland homogenates was found to increase 5- to 6-fold from late pregnancy to Day 8 of lactation, while that of monoamine oxidase in the isolated mitochondria decreased slightly over the same period while the specific activity of monoamine oxidase decreased 5-fold. The cytochrome oxidase to monoamine oxidase ratio was followed throughout the pregnancy-lactation cycle in total mammary homogenates, isolated mammary parenchymal cells, and isolated mammary mitochondria. The pattern was the same in each preparation with little change until late pregnancy and then a 3- to 4-fold increase occurred and values reached a maximum by Day 8 of lactation. Electron micrographs of midpregnant and midlactating mammary parenchymal cells in situ were prepared, and changes in the mitochondrial morphology noted. The most significant change is the large increase in number of inner membrane cristae and an increase in matrix density in the lactating gland cell.

Gossypol prevents activation of purified proenzyme of human seminal plasma acidic proteinase.

Gossypol inhibits the potential activity of the proenzyme form of human seminal plasma acidic proteinase, but has no effect on the active enzyme under the conditions tested. Inhibition of proenzyme is rapid and pH-dependent: 50% inhibition can be observed at gossypol concentrations of approx. 1.5 X 10(-5) M. SDS-polyacrylamide gel electrophoresis indicates that treatment of proenzyme with gossypol prevents the formation of active enzyme that normally occurs on acidification. Determination of free amino groups with 1-fluoro-2,4-dinitrobenzene suggests that gossypol reacts with 7.8 out of the 11.0 lysine residues in proenzyme: such a reaction could interfere with the activation process.

PIP: Studies of the effect of gossypol on the purified proenzyme of human seminal plasma acidic proteinase suggest that, while there is no effect on the active enzyme, the potential activity of the proenzyme form is inhibited. When the purified proenzyme was incubated at pH 8.0 with 0.25 mM of gossypol, 70% of potential activity was abolished within 2.5 minutes; moreover, this inhibitory activity was progressive, to the extent that only 5% of the original activity remained 90 minutes after incubation. When the concentrations of gossypol were varied, 50% inhibition of the potential activity of the proenzyme was observed at concentrations of approximately 15 mcgM. The reaction between gossypol and proenzyme was further found to be pH-dependent; a pH of at least 6.5, optimally 8.0, was required for activity inhibition. To determine whether treatment with gossypol altered protein structure, the active enzyme and proenzyme were preincubated with gossypol and subjected to SDS-polyacrylamide gel electrophoresis. Gossypol treatment decreased the potential activity of the proenzyme by 97%, but failed to affect the active enzyme. Studies on the amino acids affected suggested that gossypol protected 7.8 of 11 lysine residues in proenzyme from reaction with FDNB, presumably by formation of Schiff's bases. The physiological significance of the gossypol inhibition of seminal plasma acidic proteinase proenzyme remains unclear. Since the acidic proteinase requires acid for activation, it is unlikely that the enzyme plays a role in fertilization. It is more probable that seminal plasma acidic proteinase disposes of the remains of the ejaculate after intercourse, at a point when the vaginal pH has become acidic again. Thus, inhibition by gossypol could interfere with this "cleaning up" process.

Distinct testicular 17-ketosteroid reductases, one in interstitial tissue and one in seminiferous tubules. Differential modulation by testosterone and metabolites of testosterone.

The final step in the biosynthesis of testosterone is the reduction of androstenedione, which is catalyzed by the microsomal enzyme 17-ketosteroid reductase. Evidence is presented which suggests that there are two distinct 17-ketosteroid reductases in rat testes, one in interstitial tissue and one in seminiferous tubules. The two enzymes have different pH optima, 5.6 for the one from interstitial tissue and 6.5 for the one from seminiferous tubules. At the optimum pH, a 70-fold difference in Km values was observed, 17 muM for the interstitial tissue enzyme and 0.25 muM for the enzyme from seminiferous tubules. Testosterone and metabolites of testosterone have very different effects of each of these enzyme activities. The interstitial tissue enzyme activity is inhibited by testosterone and several 5alpha-reduced metabolites of testosterone and by estrogens. The most potent inhibitor of the steroids investigated was 5alpha-androstane-3alpha, 17beta-diol, followed by 17beta-estradiol approximately equal to dihydrotestosterone greater than testosterone greater than estrone greater than estriol. 5alpha-Androstane-3alpha, 17beta-diol and 17beta-estradiol were shown to act by competitive inhibition with apparent Ki values of 2.2 and 3.7 muM, respectively. In contrast, it was demonstrated that among the above steroids, only dihydrotestosterone inhibits the 17-ketosteroid reductase activity of seminiferous tubules and this inhibition was only observed at very high concentrations of inhibitor. Testosterone stimulated the 17-ketosteroid reductase activity of seminiferous tubules. 5alpha-Androstane-3alpha, 17beta-diol at low concentrations stimulated the enzyme activity from seminiferous tubules, while it had no effect at high concentrations. The remainder of the steroids tested had no effect on the 17-ketosteroid reductase activity of seminiferous tubules. The difference in response of the two enzyme activities suggests a mechanism for local regulation of testosterone synthesis in each testicular compartment that does not involve directly pituitary gonadotropins.

PIP: 2 distinct 17-ketosteroid reductases, 1 in interstitial tissue and the other in the seminiferous tubules, were identified in rat testes and characterized. The pH optima was 5.6 for the interstitial tissue enzyme and 6.5 for the seminiferous tubule enzyme. At optimum pH, K m values for the interstitial tissue enzyme was 17 mcM while that for the seminiferous tubule enzyme was .25 mcM. Testosterone, several 5alpha-reduced testosterone metabolites, and estrogens inhibited interstitial tissue enzyme activity, with 5alpha-androstane-3alpha, 17beta-diol being the most potent inhibitor, followed by 17beta-estradiol and dihydrotestosterone, testosterone, estrone, and estriol. 5alpha-androstane-3alpha, 17beta-diol and 17beta-estradiol were found to act by competitive inhibition. Of the above steroids, only dihydrotestosterone was able to inhibit enzyme activity in the seminiferous tubules, and then at only very high concentrations of the androgen. 17-ketosteroid reductase activity in seminiferous tubules was stimulated by testosterone and low concentrations of 5alpha-androstane-3alpha, 17beta-diol. The results suggest an extrapituitary mechanism for the local regulation of testosterone synthesis in interstitial tissue and the seminiferous tubules.

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

Comparison between testosterone enanthate-induced azoospermia and oligozoospermia in a male contraceptive study. III. Higher 5 alpha-reductase activity in oligozoospermic men administered supraphysiological doses of testosterone.

The administration of exogenous testosterone (T) to eugonadal men causes suppression of gonadotropin secretion and thus of spermatogenesis. This is currently being investigated as a possible method of hormonal male contraceptive, but complete suppression of spermatogenesis to azoospermia is induced in only 50-70% of Caucasian men; the remainder maintain a low rate of spermatogenesis. The basis for this polymorphism in response is unclear. The enzyme 5 alpha-reductase (5 alpha R) converts T to dihydrotestosterone (DHT) and is important in determining the magnitude of the androgen stimulus in some tissues. We investigated whether the maintenance of spermatogenesis in men remaining oligozoospermic while receiving suppressive doses of T is associated with evidence of increased 5 alpha R activity. Thirty-three normal men were given 200 mg T enanthate (TE), im, weekly in a clinical trial of hormonal male contraception. The MCR of T (MCRT) and the conversion ratio of T to DHT (CRT-DHT) were measured by infusion of [3H]T, plasma levels of DHT and androstanediol glucuronide (AdiolG) were measured by RIA, and 24-h urinary steroid metabolites were measured by capillary column gas chromatography. Sperm density decreased in all men; 18 achieved azoospermia by 20 weeks of treatment, and the remainder had a mean sperm density of 2.0 +/- 0.8 x 10(5)/mL at that time. This treatment caused increases in plasma T levels and MCRT, but with no differences between azoospermic and oligozoospermic responders. There were no differences in CRT-DHT plasma DHT, or AdiolG before treatment, but after 16 weeks, CRT-DHT had increased in the oligozoospermic responders, but not in the azoospermic responders. TE treatment increased plasma DHT and AdiolG levels in both groups, but the increases in both 5 alpha R metabolites were significantly greater in the oligozoospermic responders. Urinary excretion of etiocholanolone and androsterone was increased after 16 weeks of TE treatment, but did not differ between the two groups, andetiocholanolone/androsterone ratios did not differ greatly from unity. There was no change in urinary excretion of tetrahydrocortisol, allo-tetrahydrocortisol, or cortisone after 16 weeks of TE treatment in either group. These results suggest that after TE administration there is a selective increase in 5 alpha R activity in those men who remain oligozoospermic, but not in those becoming azoospermic. This difference in the androgenic milieu may underlie the incomplete suppression in the oligozoospermic responders, in whom a low rate of spermatogenesis is maintained despite the apparent absence of gonadotropins.

PIP: The administration of exogenous testosterone (T) to eugonadal men causes suppression of gonadotropin secretion and thus of spermatogenesis. This is currently being investigated as a possible method of hormonal male contraceptive, but complete suppression of spermatogenesis to azoospermia is induced in only 50-70% of Caucasian men; the remainder maintain a low rate of spermatogenesis. The basis for this polymorphism in response is unclear. The enzyme 5 alpha-reductase (5 alpha R) converts T to dibydrotestosterone (DHT) and is important in determining the magnitude of the androgen stimulus in some tissues. We investigated whether the maintenance of spermatogenesis in men remaining oligozoospermic while receiving suppressive doses of T is associated with evidence of increased (TE), im, weekly in a clinical trial of hormonal male contraception. The MCR of T (MCRT) and the conversion ratio of T to DHT (CRT-DHT) were measured by infusion of [3H]T, plasma levels of DHT and androstanediol glucuronide (AdiolG) were measured by RIA, and 24-h urinary steroid metabolites were measured by capillary column gas chromatography. Sperm density decreased in all men; 18 achieved azoospermia by 20 weeks of treatment, and the remainder had a mean sperm density of 2.0 +/- 0.8 x and MCRT, but with no differences between azoospermic and oligozoospermic responders. There were no differences in CRT-DHT plasma DHT, or AdiolG before treatment, but after 16 weeks, CRT-DHT had increased in the oligozoospermic responders, but not in the azoospermic responders. TE treatment increased plasma DHT and AdiolG levels in both groups, but the increases in both 5 alpha R metabolites were significantly greater in the oligozoospermic responders. Urinary excretion of etiocholanolone and androsterone was increased after 16 weeks of TE treatment, but did not differ between the two groups, andetiocholanolone/androsterone ratios did not differ greatly from unity. There was no change in urinary excretion of tetrahydrocortisol, allo-tetrahydrocortisol, or cortisone after 16 weeks of TE treatment in either group. These results suggest that after TE administration there is a selective increase in 5 alpha R activity in those men who remain oligozoospermic, but not in those becoming azoospermic. This difference in the androgenic milieu may underlie the incomplete suppression in the oligozoospermic responders, in whom a low rate of spermatogenesis is maintained despite the apparent absence of gonadotropins. In the UK, physicians recruited 33 healthy men aged 21-41 to a clinical trial of weekly intramuscular injections of 200 mg testosterone enanthate (TE) (Testoviron) for up to 18 months. 18 (55%) of the men achieved azoospermia after 20 weeks of treatment. The sperm density in the remaining 15 men (45%) stabilized at a mean density of 2(+or- 0.8) million/ml and stayed oligozoospermic for the remainder of the clinical trial. Plasma samples taken immediately before and 1, 2, 4, and 7 days after the 1st and 16th TE injections and after 2, 4, 8, and 12 weeks of treatment allowed the researchers to compare the activity of 5alpha-reductase (5alphaR). 5alphaR converts T to the more potent androgen dihydrotestosterone (DHT) and plays a key role in determining the magnitude of the androgen stimulus in some tissues. Exogenous testosterone (T) increased plasma T levels and the mean conversion rate of T (MCRT), but there were no differences between azoospermic and oligozoospermic men. Before treatment there were no differences in plasma DHT and androstanediol glucuronide (AdiolG) levels between the two groups. After 16 weeks, the conversion ratio of T to DHT (CRT-DHT) increased in oligozoospermic men (3.1% vs. 4%; p 0.05) but not in azoospermic men, whereas before treatment it was essentially the same in both groups. Exogenous T significantly increased both plasma DHT and AdiolG levels in both groups, but the increases in both these 5alphaR metabolites were significantly higher in oligozoospermic men than azoospermic men (p 0.02 and 0.01, respectively). (Abstract Truncated)

Influence of medroxypregesteroneacetate on testosterone metabolism by cultured human fibroblasts: a model for drug-steroid interaction.

PIP: Medroxyprogesteroneacetate (MPA) was used to study drug-steroid interaction in an in-vitro cell culture system of human skin fibroblasts from prepubertal children. MPA did not alter testosterone utilization in 9 of the 10 cell lines studed. The addition of MPA inhibited the formation of androstanediol by nearly 53% suggesting an inhibition of 3 alpha-hydroxysteroid dehydrogenase. In 3 cell lines, dihydrotestosterone increased.^ieng

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.

Effect of estrogen on triacylglycerol metabolism: inhibtion of post-heparin plasma lipoprotein lipase by phosvitin, an estrogen-induced protein.

PIP: The effects of phosvitin and lipovittelin on partially purified postheparin plasma levels of lipoprotein lipase (LPL) and triacylglycerol (TGL) and adipose tissue LPL were studied in laying and nonlaying female turkeys and estrogen-treated male turkeys. Postheparin plasma lipolytic activities and those of LPL and TGL decreased 2- to 3-fold after the onset of egg production, while a 24-fold increase in triacylglycerol (TG) was observed. Lipovittelin had no effect on either TGL or LPL, while phosvitin, in a dose of 3 mcg protein/ml assay mixture, had a strong inhibitory effect on plasma LPL and chicken adipose tissue LPL. TGL was not affected by phosvitin. The results suggest that phosvitin may have a role in the regulation of adipose tissue and plasma levels of TG in laying birds.^ieng

Pharmacokinetic drug interactions with oral contraceptives.

Oral contraceptive steroids are used by an estimated 60 to 70 million women world-wide. Over the past 20 years there have been both case reports and clinical studies on the topic of drug interactions with these agents. Some of the interactions are of definite therapeutic relevance, whereas others can be discounted as being of no clinical significance. Pharmacological interactions between oral contraceptive steroids and other compounds may be of 2 kinds: (a) drugs may impair the efficacy of oral contraceptive steroids, leading to breakthrough bleeding and pregnancy (in a few cases, the activity of the contraceptive is enhanced); (b) oral contraceptive steroids may interfere with the metabolism of other drugs. A number of anticonvulsants (phenobarbital, phenytoin, carbamazepine) are enzyme-inducing agents and thereby increase the clearance of the oral contraceptive steroids. Valproic acid has no enzyme-inducing properties, and thus women on this anticonvulsant can rely on their low dose oral contraceptive steroids for contraceptive protection. Researchers are now beginning to unravel the molecular basis of this interaction, with evidence of specific forms of cytochrome P450 (P450IIC and IIIA gene families) being induced by phenobarbital. Rifampicin, the antituberculous drug, also induces a cytochrome P450 which is a product of the P450IIIA gene subfamily. This isozyme is one of the major forms involved in 2-hydroxylation of ethinylestradiol. Broad spectrum antibiotics have been implicated in causing pill failure; case reports document the interaction, and general practitioners are convinced that it is real. The problem remains that there is still no firm clinical pharmacokinetic evidence which indicates that blood concentrations of oral contraceptive steroids are altered by antibiotics. However, perhaps this should not be a surprise, given that the incidence of the interaction may be very low. It is suggested that an individual at risk will have a low bioavailability of ethinylestradiol, a large enterohepatic recirculation and gut flora particularly susceptible to the antibiotic being used. Two drugs, ascorbic acid (vitamin C) and paracetamol (acetaminophen), give rise to increased blood concentrations of ethinylestradiol due to competition for sulphation. The interactions could have some significance to women on oral contraceptive steroids who regularly take high doses of either drug. Although on theoretical grounds adsorbents (e.g. magnesium trisilicate, aLuminium hydroxide, activated charcoal and kaolin) could be expected to interfere with oral contraceptive efficacy, there is no firm evidence that this is the case. Similarly, there is no evidence that smoking alters the pharmacokinetics of oral contraceptive steroids. These agents are now well documented as being able to alter the pharmacokinetics of other concomitantly administered drugs.(ABSTRACT TRUNCATED AT 400 WORDS)

PIP: The pharmacokinetics and clinical significance of the major drug interactions seen with oral contraceptives are reviewed, both drugs interfering with pill efficacy, and situations where pills interfere with action of other drugs. Drugs affecting contraceptive efficacy include anticonvulsants, antibiotics, rifampicin, griseofulvin, ascorbic acid, and acetaminophen. Phenytoin is the most common anticonvulsant reported to cause contraceptive failure. It as been established by measurements of steady-state ethinyl estradiol levels, sex hormone binding globulin levels, and pharmacokinetic drug concentration curves that both ethinyl estradiol and levonorgestrel levels are decreased during phenytoin and carbamazepine intake. Induction of certain cytochrome P450 isozymes is probably responsible. Neither the causation or even the existence of drug interaction with antibiotics is definitely known, although case reports of pregnancies abound. Rifampicin is an exception, where enzyme induction clearly occurs. Ascorbic acid and acetaminophen are atypical for increasing the therapeutic effect of ethinyl estradiol. The effect of benzodiazepines depends on the type of drug metabolism: drugs oxidized and nitroreduced, e.g. chlordiazepoxide, alprazolam, diazepam, and nitrazepam, exhibit reduced clearance during pill intake. Clearance of cyclosporin, prednisolone, alcohol, caffeine and theophylline are also slowed by orals. Pills accelerate clearance of salicylic acid and morphine.

Drug-induced anaemias.

Many drugs have been reported to have caused anaemia. The most serious form involves marrow aplasia, but the way in which this is produced is not understood. A number of drugs lead to megaloblastic anaemia and where this is caused by interference with dihydrofolate reductase the explanation is obvious. However, some substances, notably anticonvulsants, cause megaloblastic anaemia by some other mechanism. A number of drugs cause intestinal bleeding with anaemia as a result. Sideroblastic anaemia is a relatively rare condition, sometimes caused by drugs, particularly those used in the treatment of tuberculosis. Leukaemia very occasionally supervenes in patients with drug-induced aplastic anaemia.

PIP: Several forms of drug-induced anemia are discussed. Anemia resulting from toxic effects on the marrow may occur after large doses or long treatment courses of alkylating agents, the plant alkaloids vinblastine and vincristine, and antibiotics used in cancer chemotherapy. A lesion of the stem cells in bone marrow is thought to be caused. Aplastic anemia has been produced by chloramphenicol in a small percentage of cases. This has led to its disuse except when no suitable alternative is available or where the mortality of the disease being treated is high. Some nonnarcotic analgesics, e.g., amidopyrine, have caused agranulocytosis. Gold injections have also been implicated. Insecticides or an inhaled agent such as benzine or a glue solvent may cause hypoplastic anemia. A list is given of drugs that have been reported as having caused aplastic anemia. Chromosomal changes have rarely been reported. An alleric mechanism is sometimes responsible for drug-induced aplastic anemia. There may be individual variations in ability to metabolize a drug. Treatment of drug-induced aplastic anemia requires transfusions. Bone marrow transplants have also been used. Antibiotic therapy is needed. Oral contraceptives may be of value if there is menorrhagia. Megaoloblastic anemia may be due to defective metabolism of folate. Anticonvulsant drugs may also cause megaloblastic anemia, especially primidone. Giving folic acid with these drugs may prevent this development. Oral contraceptives have been reported to cause folate depletion but megaloblastic anemia has not been shown to follow. Alimentary bleeding with peptic ulcer or following drug use may cause anemia. Sideroblastic anemia may be a congenital abnormality of iron metabolism or an acquired form induced by drugs or lead poisoning. Pyridoxine therapy is used. Drug-induced leukemia may follow use of radioactive compounds or may develop in patients with a drug-induced aplastic anemia.

Effect of benzo(a)pyrene and chlorpromazine on aryl hydrocarbon hydroxylase activity from rat tissues.

PIP: The effects of 3,4-benzo(a)pyrene (BP) and chlorpromazine (CP) on th e distribution and relative levels of aryl hydrocarbon hydroxylase (AHH) in rat tissue were studied in vitro. The metabolism of AHH in BP-treated lymph node, lung, prostate, kidney, salivary glands, liver, spleen and mammary gland was markedly increased, while only lung, liver, and kidney tissue showed a marked increase in CP experiments. Prior to treatment, the metabolism of polycyclic hydrocarbons occurred primarily in the liver. However, kidney and lung tissues became much more important in metabolizing these hydrocarbons after exposure to BP or CP. The importance of AHH activity in protective tissues of entry into the body is discussed.^ieng

Effect of cyproterone acetate on the proteinase activities of adult rat testis and epididymis.

PIP: The in vivo and in vitro effects of cyproterone acetate (CA), an antiandrogenic compound, on the proteinase activities in epididymal and testicular spermatozoa in male albino rats was studied. CA was injected intramuscularly at a dose of 50 mg/kg daily for 10, 20, and 30 days. The testis and epididymis were homogenized and submitted for enzyme assay. The in vitro experments involved the incubation of supernatents from centrifuged testis and epididymis for 30 minutes with CA. Proteinases were assayed using acid-denatured hemoglobin as substrate. Acid proteinase activities increased in both testis and epididymis, but the inhibition of neutral and alkaline proteinase activities was greater in epididymis than testis with both long- and short-term treatment with CA. It is suggested that CA inhibits the maturational processes in the epididymis rather than spermatogenesis in the testis.^ieng

Influence of chlorpromazine on the positive and negative feed-back mechanism of oestrogens in man.

PIP: It was determined whether all the different neuroendocrine actions of estrogen are competitively antagonized by phenothiazines to test the putative analogy between the 2 types of molecular receptor. 12 men aged 22-25 years were tested on 3 days and then given 2 X 20 mg ethinylestradiol (EE) for 4 days with either 2 X 50 mg chlorpromazine (6 cases) or a placebo (6 cases). Neurohypophyseal activity and adenohypophyseal activity were tested. There was a lack of significant changes in pulse, blood pressure, body weight, and psychosexual factors. Blood alkaline phosphatases decreased in all 12 men after estrogen, and an inhibitory effect of estrogens alone was seen on blood FSH and on the 2 and 5 fraction of urinary 17-keto-steroids. The neurophysine basal level and the growth hormone peak response to hypoglycemia showed a stimulatory effect. There was no effect on FSH by chlorpromazine or on the inhibition of 17-keto-steroids due to estrogens. However, chlorpromazine lessened the neurophysine increase and abolished the facilitatory effect of estrogens on growth hormone responsibeness to hypoglycemia. In 60% of the cases TSH blood levels were undetectable and unvaried.^ieng

Retroviruses: new viral infections in man.

PIP: Human retroviruses, or RNA viruses, including the 2 HIV agents associated with AIDS, and the 2 HTLV agents causing leukemia, are described from the viewpoint of history, detection, serology, transformation mechanism, disease pathophysiology, genetic function, associated disease, and related viruses. Both HTLV and HIV infect the human T-lymphocytes, also known as CD4 or helper cells. Both can now be grown in culture, and their genomes are well characterized. HTLV, an acronym for human T-lymphotropic leukemia virus, causes the fulminating adult T-cell leukemia-lymphoma (ATLL), 1st described in 1977. It is prevalent in population clusters, notably in the Caribbean and in southwestern Japan, and is spread by sexual, blood and perinatal routes, as is HIV. It is thought to promote transformation of target cells by release of growth promoting, soluble factor, perhaps a product of the viral "tat" gene. Besides leukemia, HTLV-1 causes a myelopathy sometimes called tropical spastic paraparesis. HIV, formerly known as HTLV-III, causes depletion of the T-cells, and also infects the brain and nervous system. IT has also been isolated from semen, cervical secretions, saliva, monocytes, milk, endothelial cells, tears and cornea. HIV has 5 more genes than HTLV, which regulate transcription, mRNA processing and virus maturation. Parts of the HIV genome are highly heterogeneous, and mutate rapidly, notable sections of the envelope protein. Thus, HIV has 2 main subtypes, but others are known and probably exist. Approaches toward developing AIDS therapeutic agents as of 1987 are outlined: an effective drug should cross the blood-brain barrier. Several anti-viral drugs that block the enzyme reverse transcriptase area being investigated. Possible mechanisms for growth of Kaposi's sarcoma, activation of herpes type viruses, and animal viruses related to HTLV and HIV are discussed.^ieng

Response of Ethiopian human immunodeficiency virus type 1 isolates to antiviral compounds.

Human immunodeficiency virus type 1 (HIV-1) isolates of 8 Ethiopian and 8 Swedish untreated AIDS-patients were examined for their sensitivity to 3'-azido-3'-deoxythymidine (AZT), 2',3'-dideoxyinosine (ddI) and leukocyte-derived interferon-alpha (IFN-alpha). No significant difference in drug sensitivity was found between Ethiopian and Swedish isolates, which all were sensitive to AZT, ddI and IFN-alpha except for one Swedish isolate. This isolate exhibited a mutation at amino acid position 215. These results suggest that it should be possible to perform clinical trials in Ethiopia using the same dose regimens as in Sweden.

PIP: Human immunodeficiency virus (HIV-1) isolates from 8 Ethiopian and 8 Swedish AIDS patients, none of them treated with antiviral drugs, were compared for sensitivity to azido-deoxy-thymidine (AZT), dideoxy-inosine (ddI) and interferon-alpha. HIV was isolated from peripheral blood mononuclear class, identified by Western blot and nucleotide sequencing, and passaged 1-3 times. Sensitivity to the 3 drugs, expressed as ED50s relative to positive controls, was determined by culturing HIV in the presence of drugs in a range of concentrations and assaying the supernatant for p24 antigen and the virus pellet for reverse transcriptase (RT). Dose-dependent anti-HIV activity for AZT was seen in the 8 Ethiopian isolates, and ED50s for p24 antigen and RT activity were correlated. 1 Ethiopian HIV isolate was sensitive to ddI, and another, to interferon-alpha. 1 Swedish HIV was resistant to AZT, and on analysis had a mutation from threonine to tyrosine at position 215. There were no significant differences between ED50s for interferon in the Swedish and Ethiopian HIVs. Combined data for each drug showed correlation between the p24 antigen and RT activities of the Ethiopian and Swedish HIVs. Since there was no resistance observed in the Ethiopian HIV to AZT or ddI, low-dose treatment would probably slow progression of HIV infection in Ethiopians, if these drugs could be made available for clinical trials.

Contraception with intrauterine devices.

PIP: A review of the history of contraception with intrauterine devices, characteristics of present devices, and directions of current research is presented. The serious need for population control is not yet being met by today's inconvenient, ineffective, or unsafe methods. Intrauterine devices have been best for international family planning programs because they are cheap, easily installed, and provide continuous protection. There are many different models that have been and are being used, with different effectiveness and complication rates. The most commonly used today is the Lippes Loop, with a pregnancy rate of 2.8/100 years of woman use and an expulsion rate of 10.4. Most of these failures occur in the first few months of use, after which these rates are greatly reduced. The removal rate because of bleeding or pain for the Lippes device is 14.0. Other devices commonly used have pregnancy rates ranging 1.3-4.7, expulsion rates of 2.6-25.8, and removal rates of 13.5-22.1. Expulsion is directly related to the size and design of the IUD and the age and parity of t,e recipient. It is important to match the size of the device used to the individual characteristics of the patient. Research is seeking a design that will implant itself in the endometrium to resist expulsion, but not too deeply so that it is covered. Removal for bleeding and pain remains the most frequent complication of the IUD, and it partly depends on the skill of the inserting physician and how well the patient is psychologically prepared for side effects in the first months of use. Pregnancy is the most significant IUD complication. The key to an effective IUD is an understanding of its antifertility mechanism, which has thus far eluded researchers. The IUD prevents implantation of the blastocyst in the uterine wall, which may be due to a foreign-body reaction in the endometrium. IUDs with copper cause a greater reaction than plastic devices and provide hope for a very effective device; particularly the T-shaped design, which resists expulsion. The most promising new IUD is the Dalkon Shield. It has small projections that imbed in the endometrium and a broad surface for contact with the uterine wall. In preliminary experiments the pregnancy rate with this device was 1.1, the expulsion rate 2.3, and the removal rate 2.0, much lower than that with any other device yet developed. It is concluded that IUDs such as the Dalkon Shield can provide safe contraception with high effectiveness.^ieng

Association between glucose-6-phosphate dehydrogenase deficiency and neonatal jaundice: interaction with multiple risk factors.

This nonconcurrent cohort study was carried out to evaluate the association of neonatal jaundice with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and its interactions with other risk factors. The G-6-PD enzyme activity of 12,379 neonates was screened by a semi-quantitative fluorometric assay and double-checked by a quantitative method to identify a G-6-PD deficient cohort of 333 neonates. Matched with these on birth date, sex and delivery hospital were a G-6-PD normal cohort of 653 neonates. Neonatal jaundice was defined by a peak serum bilirubin (PSB) level of > or = 15 mg/dl. A significant association between G-6-PD deficiency and neonatal jaundice was observed in male but not female neonates. There was an inverse dose-response relation between G-6-PD activity and neonatal jaundice among male neonates. Both hypoxia/asphyxia and maternal hepatitis B surface antigen (HBsAg) carrier status were associated with an increased risk of neonatal jaundice among G-6-PD deficient but not G-6-PD normal male neonates. Based on multiple regression analyses, an additively synergistic effect on PSB level and severe jaundice (PSB > or = 20 mg/dl) was observed for G-6-PD deficiency and maternal HBsAg carrier status.

PIP: Researchers compared data on 333 newborns with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency at 5 public and 5 private hospitals in Taiwan with data on 653 birth date, sex, and delivery hospital matched newborns to examine the peak serum bilirubin (PSB) level and incidence of neonatal jaundice of both G-6-PD deficient and G-6-PD normal newborns. They also wanted to determine whether an association exists between G-6-PD activity level and incidence of neonatal jaundice and associations between G-6-PD deficiency and other likely risk factors of neonatal jaundice. A significant association between G-6-PD deficiency and neonatal jaundice existed among male neonates but not female neonates. Male neonates had a considerably higher incidence of neonatal jaundice than did female neonates (11.6% vs. 6.2%). There was a significant inverse dose-response relationship between G-6-PD activity and neonatal jaundice among the male neonates (p.01). For example, the relative risk was 1.78 for 20.1-29.9 relative intensity, 2.01 for 15.1-20, 2.61 for 10.1-15, and 4.07 for 10. Maternal hepatitis B surface antigen (HBsAg) carrier status and hypoxia/asphyxia significantly increased the risk for G-6-PD deficiency in male neonates (p.05). The multiple regression analysis indicated a significant effect of G-6-PD deficiency on the PSB level and the incidence rate of severe neonatal jaundice. There was a similar significant interaction between G-6-PD deficiency and maternal HBsAg carrier status.

Folic acid absorption, anticonvulsant and contraceptive therapy.

PIP: Studies of the effects of oral contraceptives and other drugs on folic acid absorption are reviewed. In 1 study, estradiol, progesterone, and estrone did not inhibit folate conjugase nor interfere with the passage of folate conjugase across the lysosomal membrane. 12 women taking an oral contraceptive (norethisterone and ethinyl estradiol) had significantly higher mean serum folate levels at Day 20 of the menstrual cycle than at Day 5 (7.63 ng/ml and 5.36 ng/ml), though no significant difference was observed with compared with a control group. In another study, women taking oral contraceptives showed significantly lower mean peak serum folate levels after saturation with yeast polyglutamate when compared with controls. It is suggested that steroid hormones increase the rate of clearance of folate from the blood.^ieng

Influence of nutritional status on pharmacokinetics of contraceptive progestogens.

PIP: In response to recent studies from India suggesting that malnutrition, as assessed by anthropometric indexes, affects metabolism of oral progestogens, this study administered a mini-pill containing .35 mg of norethindrone (NET) and combination pills containing 250 or 150 mcg of d-norgestrel (d-NG) and either 50 or 30 mcg ethinyl estradiol as a single dose for fasting women of high and low income. Blood samples were collected for up to 24 hours for NET and 80 hours for the combination pills. Pharmacokinetics were evaluated by a least-squares method. Anthropometric measurements were also made. Peak NET levels occurred within 1-2 hours; half-life of plasma NET was shorter among low income, malnourished women compared with high income, well-nourished women. A direct correlation between weight/height and half-life of the drug suggests that malnutrition enhanation rate and reduces NET's half-life. Peak levels for d-NG also were reached between 1 and 2 hours after dosing. In well-nourished women, the decline in plasma d-NG was tri-exponential; malnourished women showed a biphasic curve with a neglible alpha-phase. Therefore, the lower the nutrition status, the faster the plasma clearance of these 2 orally administered compounds. Studies inn rabbits designed to elucidate this connection showed a significant elevation in specific activities of liver microsomal glucuronyl transferase and cytochrome-p450 in undernourished compared with control animals. There was also an increase in the amount (but not affinity) of uterine progesterone receptors in undernourished animals. Another study of a small group of Thai and Indian women showed positive correlation between anthropometric indexes and post peak plasma NET levels; however, an obesity study of Thai women found no such correlation.^ieng