Pilot study with technosphere/PTH(1-34)--a new approach for effective pulmonary delivery of parathyroid hormone (1-34).

Sequential subcutaneous PTH injection therapy (repeated 14 days of PTH administration and a subsequent treatment pause for a few weeks) is known to increase bone mineral density in patients with osteopenic disorders. Alternative methods of drug delivery may be beneficial in increasing compliance. A pilot study was performed in 10 healthy volunteers (4 female/6-male, age: 25.6 +/- 3.5 years, BMI: 22.3 +/- 2.4 kg/m 2, mean +/- SD) to assess the pharmacokinetic profiles of 1600 IU of PTH(1 - 34) using the pulmonary Technosphere drug delivery system in comparison to a subcutaneous injection of 400 IU. The treatments were administered in the morning after an overnight fast and blood samples for measurement of PTH(1 - 34), PTH(1 - 84), and calcium and calcitonin were taken over a period of 6 hours. Both injection and pulmonary application of PTH(1 - 34) were well tolerated. After pulmonary administration of Technosphere/PTH(1 - 34), PTH(1 - 34) appeared in the serum with a faster concentration increase (T max: pulmonary 10 +/- 5 min vs. subcutaneous 28 +/- 8 min, p < 0.001) and with higher maximal concentrations (C max : pulmonary 309 +/- 215 pmol/l vs. subcutaneous 102 +/- 45 pmol/l, p < 0.05) as compared to the subcutaneous injection. The relative bioavailability of pulmonary Technosphere/PTH(1 - 34) was calculated to be 48 %. No differences were seen between pulmonary and subcutaneous application with regard to the PTH(1 - 84), calcitonin and calcium concentrations. In conclusion, pulmonary application of Technosphere/PTH(1 - 34) appears to be an effective and thus attractive candidate for PTH substitution therapy in osteoporosis and other conditions leading to a decrease in bone mineral density.

Hypothalamic-pituitary-gonadal function in anorexia nervosa and bulimia.

Patients with anorexia nervosa (AN) exhibit neuroendocrine abnormalities that may result solely from emaciation or may reflect defective endocrine mechanisms which are intrinsic to disordered eating even in the absence of starvation. To distinguish these possibilities, we have studied indices of hypothalamic-pituitary-gonadal (HPG) function in 9 patients with AN, 12 normal weight patients with bulimia and recent or current oligomenorrhea, and 8 normal weight controls. Measurement of 24-hour luteinizing hormone (LH) secretion with 30-min sampling revealed significantly fewer LH secretory spikes and a trend toward lower mean 24-hour LH levels in both bulimic and anorectic patients than in controls. Stimulation with gonadotropin releasing hormone produced elevated LH responses in the bulimic group and blunted LH responses in the anorectic group. Stimulation with estradiol revealed diminished LH augmentative responses and a trend toward diminished follicle stimulating hormone augmentative responses among bulimic as well as AN patients compared to controls. In each instance, the bulimic group tended to show within-group heterogeneity, with some individuals falling within the AN range. These findings suggest that HPG axis abnormalities in eating disordered patients cannot entirely be attributed to emaciation and that factors other than subnormal weight contribute to disturbed hypothalamic-pituitary functioning in these patients.

Ovulation induction in anestrous bitches by pulsatile administration of gonadotropin-releasing hormone.

Preliminary studies in anestrous Beagle bitches demonstrated that a single injection of gonadotropin-releasing hormone (150 micrograms) produced a rapid, physiological rise in serum estradiol lasting 1-3 days while progesterone remained below 1 ng/ml, whereas serial injections of FSH rapidly produced greater elevations in estradiol and a rapid rise in progesterone over 2 ng/ml. Consequently, attempts to induce fertile ovulation by means of pulsatile intravenous administration of GnRH (1 pulse/1.5 hours for 6-12 days; 0.04-0.43 micrograms/kg body weight/pulse) were conducted in eight anestrous bitches. Willingness to mate, serum progesterone levels and results of mating were monitored. In six of the eight bitches, vulval and vaginal signs of proestrus occurred by Day 2-4 after initiation of treatment (Day 0); but, two bitches showed negligible responses. In five of the six bitches in which proestrus was induced, behavioral (n = 4) and vaginal (n = 5) correlates of early estrus occurred by Day 5-7 of treatment and breedings occurred over a period of 4-12 days. Following onset of estrus, four of the five bitches had increases in serum progesterone levels between Days 14 and 18 after initiation of treatment (and 4-11 days after cessation of treatment); three of them became pregnant and whelped normal litters (ranging from 9 to 11 pups). The fifth bitch did not have elevated progesterone during the induced estrus, and upon return to estrus one month later was successfully bred and whelped a normal litter of 10 pups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of androgen administered to neonatal male rats on hypophyseal gonadotropin content, secretion and response to LHRH at adulthood.

Supraphysiologic doses (1.75-3.50 mg) of testosterone propionate (TP) administered to male rats on the day of birth and 24 h later resulted in markedly reduced serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels in adult males castrated for 16 days. These effects diminished as androgen was injected on succeeding postnatal days. Since exogenous dihydrotestosterone and testosterone were similarly effective, aromatization to estrogen is not required to elicit these effects. No build-up of either gonadotropin occurred in the pituitaries of TP-treated animals; pituitary LH content was appreciably reduced, while FSH remained unchanged. These data imply that hypophyseal synthesis and secretion of gonadotropins are curtailed in adult castrated males who have been androgenized neonatally. Pituitaries of such neonatally treated animals, however, were capable of increased secretion of LH in response to a challenge of luteinizing hormone-releasing hormone. These findings are compatible with a model in which an androgen suppressible event occurs at a suprahypophyseal level, e.g., hypothalamus or higher brain centers, in the male rat during a restricted neonatal period, which is responsible for programming the development of mechanisms involved in accumulation and secretion of gonadotropins.

Menopausal hot flashes: thermoregulatory, cardiovascular, and circulating catecholamine and LH changes.

Thermoregulatory, cardiovascular and endocrine changes were simultaneously monitored in 11 post-menopausal women with frequent hot flashes (catecholamine and LH levels were measured in 5 and 6 subjects respectively). Plasma samples were obtained at 1- and 5-min intervals. Hot flashes were accompanied by abrupt increases in plasma epinephrine (about 150%) and concomitant decreases in norepinephrine (about 40%). Increased luteinizing hormone was associated with most hot flashes. A detailed sequence of hot flash-associated changes was established. An aura preceded the onset of the hot flash by several seconds. HR and FBF increased just before the onset of the flash and reached peak levels of 10-20 beats/min and 30-fold respectively. Coincident with vasodilation and sweating, finger temperature increased an average of 3.9 degrees C and esophageal temperature fell 0.2-0.6 degrees C. Flashes of both discrete and prolonged intervals were observed. Sensation was a reliable index of flash occurrence and intensity as measured physiologically. Our observations are consistent with the hypothesis that hot flashes are due to a change in the thermoregulatory set point. Furthermore, the changes in catecholamine levels are consistent with the cardiovascular changes accompanying hot flashes.

Pulsatile administration of gonadotropin-releasing hormone for induction of ovulation.

Chronic pulsatile administration of gonadotropin-releasing hormone (GnRH) was used to induce ovulation in 12 women with various ovulatory disorders. In the first group of eight patients with normal to low baseline levels of gonadotropin, seven responded favorably to the treatment. Follicular maturation was observed in 57% of the treated cycles, and normal ovulatory cycles were induced in 24% of the patients. Two patients became pregnant. The intravenous route of administration was more effective than the subcutaneous one, possibly in response to the GnRH profile after each pulse. (The amplitude of GnRH peaks after an intravenous pulse was four times that seen after a subcutaneous one.) In contrast, follicular maturation and ovulation could not be induced in four women of a second group of patients with normal baseline levels of follicle-stimulating hormone but with high and frequent pulses of luteinizing hormone. The conclusion reached was that pulsatile administration of GnRH can be a new therapeutic tool in the treatment of ovulatory disorders in women who have an insufficient endogenous release of GnRH.

Steroid receptors in rat uteri: postmortem retention of specific binding functions in crude tissue preparations.

Steroid receptor measurement by steroid binding analysis is a clinically useful procedure. The determination of steroid binding by specific receptors is thought to reflect the biological status of the test specimen and thereby aid prediction of patient response to endocrine therapy. The need for rapid excision of a specimen and transfer to a cold environment is believed necessary to allow reliable receptor evaluation. The optimal method of processing specimens for receptor assays, however, remains to be determined. This article reports our results on the hormone specific binding functions of rat uterine estrogen and progesterone receptors in relation to their time postmortem in situ. Steroid binding by inactive (cytoplasmic) and activated (nuclear) receptors and the processes of receptor transformation, translocation and nuclear association have been studied. Contrary to generally held notions, our results indicate that the binding functions were not altered up to 1.5 hours postmortem in situ relative to their behavior in incubation media at 2 degrees C. Thus, this apparent stability of the steroid receptors, in situ, allows greater freedom in the procurement of tissues for receptor analyses in clinical and basic research studies.

Gonad-gonadotrope interactions: plasma gonadotrophin levels and tumour induction in long-term castrated rats.

The patterns of gonadotrophin secretion in intact controls and in male and female rats castrated for up to 36 months were established utilizing specific radioimmunoassay methods. Plasma LH increased 14-16 fold and FSH rose 4-8 fold in rats of either sex in the first 30 day interval showed an additional 76% increase of LH in both sexes and increases in FSH of 32 and 61% in males and females, respectively. These levels were maintained for an additional 34 months. The number of hypophyseal gonadotrophin containing cells, studied by immunohistochemical localization techniques, increased following gonad removal in a pattern similar to that for the circulating hormones. Development of gonadotrophin secreting concentrations which suggests that the gonadotropes are uniquely resistant to tumourogenesis unlike mammotropes, thyrotropes, and corticotropes.

Intranuclear transformation of the estrogen receptor in adulthood: tissue and species similarities.

Previous studies in immature rodents have demonstrated the presence of two forms (4S, 5S) of salt extractable estrogen receptor in uterine nuclear preparations. The link between these binding forms appears to be that of hormone dependence and time in a precursor-product relationship. In the present study, this relationship has been observed in nuclear extracts of the uterus and anterior pituitary of intact and gonadectomized adult rats. Both forms of the estrogen receptor have also been isolated from purified nuclei of endometrial cell preparations of the adult dog. As a result of these studies, the phenomenon of intranuclear receptor transformation in estrogen action may now be extended to include (a) the physiologic state of adulthood, (b) persist in the absence of endogenous estrogens and (c) be a feature of estrogen target tissues in animal species other than rodents.

Immunoassay of serum alphafetoprotein and albumin reflects the mode of tissue preparation: implications for steroid hormone receptor assays.

The effect of various modes of tissue preparation on the retention of distinct serum proteins was determined. Specific and sensitive radioimmunologic methods were used to measure serum alphafetoprotein (AFP) and albumin(SA) in 105,000 x g hypotonic soluble (cytoplasm) and hypertonic (400mM KCl) solubilized pellets (nuclear extracts) from homogenates of immature rat estrogen target tissues. The tissue level of both serum antigens was influenced by the preparative method: cervical dislocation followed by organ isolation and a single rinse yielded the highest levels of apparent tissue AFP and SA while decapitation followed by exsanguination, organ isolation and multiple rinses resulted in the lowest levels. For the uterus, exposure of the uterine lumen enhanced reduction of serum antigen detection. The recommended procedure minimizes the inclusion of serum proteins which can interfere in the subsequent in vitro measurement of specific receptors in hormone responsive tissues.

[Effects of estradiol-7 alpha-butyric acid on hypothalamus cells]. / Effets de l' "oestradiol-7 alpha-acide butyrique" au niveau de cellules hypothalamiques.

When Rat uterus was incubated at 37 degrees with estradiol-7 alpha-butyric acid (OII-7 alpha-bu), no interference was observed with the intracellular estradiol receptors. In addition, OII-7 alpha-bu did not display estrogenic effect such as in vivo inhibition of LH secretion in Rat and in vitro increased activity of the enzyme ornithine-decarboxylase in the chick oviduct. Contrary to these negative findings, we have observed preoptic and septal cells in the guinea pig where micro-iontophoresis of OII-7 alpha-bu triggers changes of the electric activity within a second. We submit therefore, that this latter response is due to an interaction between the acid estrogen and the neuron membrane.

Estrogen receptors in different target tissues: similarities of form--dissimilarities of transformation.

The time-related uptake, retention and intracellular distribution of estrogen by different target tissues of the intact immature female rat were studied. The cytoplasmic compartment of the uterus, hypothalamus and pituitary was shown to have a primary hormone receptor complex sedimenting as 8S by sucrose density gradient analysis. Nuclear extracts from all three target tissues contained two forms of estrogen receptor complex; a 5--6S form and a more slowly sedimenting 4S species. The heavier nuclear form accumulated subsequent to the 4S complex in a time-dependent manner which differed according to target tissue. The observed intranuclear differences in properties of the estrogen receptor system may be related to the physiologic responses which characterize dissimilar estrogen target tissues. The tissue content of such serum estrogen-binding proteins as alpha1-fetoprotein and albumin were also determined. The observed levels were evaluated as possible factors in tissue estrogen retention.