Wlodzimierz Kowalski

Strategies for ovulation induction and oocyte retrieval in the lowland gorilla

Purpose: Ovulation induction and oocyte retrieval were performed in a lowland gorilla in an attempt to propagate and potentially cryopreserve embryos from an infertile animal and to advance techniques to help preserve this endangered species.Results: Following 34 days of leuprolide acetate suppression, human menopausal gonadotropins were administered for 14-days in a 32-year-old wild-born lowland gorilla. Ten oocytes were retrieved by transrectal ultrasound-guided aspiration. Other approaches to oocyte recovery were not feasible in this case. A serum estradiol concentration of 4700 pg/ml at the time of human chorionic gonadotropin administration did not induce ovarian hyperstimulation. Mature oocytes were recovered from follicles measuring 14 to 24 mm in diameter, with a corresponding average serum estradiol concentration of approximately 300 pg/ml for each mature follicle. Cryopreservation of a gorilla embryo was effected from cryopreserved gorilla spermatozoa.Conclusions: Parameters for monitoring ovulation induction in the gorilla appear to be similar to those for humans. The results indicate that the use of a gonadotropin releasing hormone agonist and higher doses of gonadotropins than previously used in gorillas appear to improve oocyte recovery.

Response of the Primate Secretory Endometrium to Subchronic Hypercortisolemia

Objective: To assess the impact of subchronic and moderate hypercortisolism on the secretary endometrium of the cynomolgus monkey. Methods: Osmotic pumps containing hydrocortisone phosphate (HP) were implanted subcutaneously in each monkey on the first day of the menstrual cycle; each monkey also received pumps containing saline in another cycle. Blood was obtained three times per week and urine was collected daily for hormone analyses. Endometriectomy was performed 13 ± 1 days after the serum estradiol (E2) peak in each study cycle. Results: Infusion of HP elevated serum cortisol levels by an average of 70%. Mean serum progesterone (P) levels were decreased by 50% during the secretory phase of HP-treatment cycles by comparison with self-control cycles (P < .01); as a result, the mean endometrial glycogen concentration was reduced by 30% (P < .05) and the activity of 17β-hydroxysteroid dehydrogenase was decreased by 70% (P < .05). Serum E2 levels were not consistently elevated by HP treatment, but cytosolic estrogen receptor levels of the endometrium were decreased by 50% (P < .01), indicating increased estrogenic stimulation. Histologic development of the secretory endometrium was retarded, but the length of the secretory phase was not affected by the treatment. Conclusion: A moderate elevation of serum cortisol levels over one menstrual cycle consistently produced a reduction in serum P and a hypoprogestogenic-hyperestrogenic response of the secretory endometrium in the cynomolgus monkey.

Disappearance and unexpected reappearance of progesterone in the circulation of the monkey: novel hormone kinetics.

1. Intravenous injection of [3H]progesterone in non‐pregnant monkeys resulted in total disappearance of the labelled hormone from the circulation within 3 h. However, 0.5‐1.75 h after disappearance the hormone reappeared, reaching 20% (median, 5%) of the initial maximal concentration. 2. Reappearance of labelled hormone was accompanied by similar fluctuations in the levels of labelled metabolites, [3H]20 alpha‐dihydroprogesterone and [3H]17 alpha‐hydroxyprogesterone, which reached 61% (median, 14%) and 120% (median, 13%), respectively, of the initial maximal concentrations. 3. Chromatography was used to separate labelled progesterone and its metabolites. Efficiency of the procedure was determined separately in each sample and for each steroid. All data were corrected for percentage recovery. 4. Analytical equations were devised, based on the theory of compartmental systems with continuously distributed time lags, to describe the unexpected kinetics of progesterone levels. The coefficients of determination ranged from 86 to 99% (median, 96%) which indicates that the equations enabled reliable prediction of hormone levels in blood within the time range studied. 5. The unexpected reappearance of labelled progesterone cannot be explained by hormone secretion but only by a delayed release from tissue stores, since progesterone does not undergo enterohepatic recirculation. Thus, a previously undescribed mechanism affecting circulating progesterone levels, and perhaps those of other hormones, exists.

Pharmacokinetics and pharmacodynamics of anordrin (2α, 17α-diethynyl-A-nor-5α-androstane-2β, 17β-diol diproprionate)

Abstract In order to determine the pharmacokinetics of anordrin a dose of 0.2 mg/kg of [3-14C]anordrin was administered i.v. to 5 cynomolgus monkeys; the same monkeys received the same dose i.m. at a later date. An additional 3 monkeys received 1.0 mg/kg of [3-14C]anordrin i.m. After administration of the compound, the dipropionate esters of anordrin were rapidly hydrolyzed to the dihydroxy parent compound, anordiol. After i.v. administration, anordrin had a mean residence time (MRT) of 5.0 ± 1.3 (SE) min. [14C]Anordiol formed from [14C]anordrin had an MRT of 139 ± 27 (SE) min. The metabolic clearance rates (MCR) of anordrin and anordiol were 55 and 34 mL/min·kg, respectively. The apparent volume of distribution at steady state (Vss) for anordrin was 276 mL/kg, 7.5% of body weight of the animals; anordiol had a much larger Vss of 4460 mL/kg. The MRT of anordiol after i.m. administration of 1.0 mg/kg of [14C]anordrin was 26.3 days. An average of 44% of the dose appeared in urine regardless of the route of administration or dose. The MRT values of total radioactivity were the same when calculated from serum or urine after an i.v. dose, but after i.m. administration, values from urine were approximately 60% of that calculated from serum, indicating that products appearing in urine had a shorter MRT than products appearing primarily in feces. A separate group of monkeys was given anordrin i.m. in doses ranging from 0.1 to 0.4 mg/kg on the first day of menses The regression of length of menstrual cycle on dose was significant (P = 0.004). Control cycle length was 30 days and the response was linear to 76 days with the maximum dose given.

Effects of subchronic infusion of dehydroepiandrosterone sulfate on serum gonadotropin levels and ovarian function in the cynomolgus monkey

OBJECTIVE To assess the impact of elevated adrenal androgen levels on ovarian function in a nonhuman primate using a repeated measures experimental design. DESIGN Osmotic pumps that released dehydroepiandrosterone sulfate (DHEAS) were implanted subcutaneously in five cynomolgus monkeys (Macaca fascicularis) for one menstrual cycle. The pumps were filled with saline for the two control cycles, one preceding and the other following DHEAS infusion. RESULTS Administration of DHEAS elevated its levels in serum fourfold and in urine sevenfold, which returned to pretreatment values in the next cycle. Serum concentrations of estradiol (E2) were reduced by 55% during DHEAS administration in both follicular and luteal phases and were still decreased in the following cycle by 69% in follicular phase and 48% in luteal phase (P less than 0.01). Luteal serum progesterone (P) levels were diminished by 52% during treatment and were accompanied by 56% reduction in immunoreactive pregnanediol excretion in urine (P less than 0.05). Serum luteinizing hormone (LH) levels were decreased during DHEAS infusion by 51% in follicular phase and 58% in luteal phase (P less than 0.01) but returned to baseline in the next cycle. Conversely, serum follicle-stimulating hormone (FSH) concentrations were increased during treatment by 70% in follicular phase and 101% in luteal phase and remained increased by 58% in follicular phase of the next cycle (P less than 0.05). Estrone excretion in urine was higher during DHEAS infusion (1.5-fold increase) but was below pretreatment values in the following cycle by 57% in follicular phase and 51% in luteal phase (P less than 0.001). Administration of DHEAS did not change significantly serum levels of sex hormone-binding globulin. The length of menstrual cycles was not affected by increased levels of adrenal androgens either. However, in the cycles that followed DHEAS infusion, follicular phase was prolonged by an average of 9 days, and luteal phase was shortened by an average of 5 days (P less than 0.01). CONCLUSIONS These data document that subchronically elevated adrenal androgen levels in primates: (1) suppress E2 and P levels, which may affect fertility; (2) differentially affect gonadotropin secretion, decreasing LH and increasing FSH serum concentrations; and (3) result in disturbances of ovarian function that persist for at least one menstrual cycle after normalization of androgen levels.

Erratum: Pharmacokinetics and pharmacodynamics of anordrin (2α,17α- diethynyl-A-nor-5α-androstane-2β,17β-diol dipropionate) (Steroids (March 1994) 59:3 (217-223))

[This corrects the article on p. 219 in vol. 49.].

Modulation of Gonadotropin and Sex Steroid Levels by Adrenal Androgens with Osmotic Pumps

Chronic exposure to an excess of adrenal androgens has been linked to the pathophysiology and the clinical picture of such endocrinological disorders as polycystic ovary syndrome (1), congenital adrenal hyperplasia (2), and hirsutism (3), conditions often associated with impaired fertility. The purpose of our study was to investigate subacute effects of elevated adrenal androgen levels on gonadotropin secretion and sex steroid concentrations in female monkeys. Of all adrenal androgens, dehydroepiandrosterone sulfate (DS) is the most abundant in the circulation, has the lowest metabolic clearance rate, and can be converted in vivo to other adrenal androgens (4). For these reasons, this steroid was chosen as a model for studying the influence of adrenal hyperandrogenaemia on the hormones of the pituitary-ovarian axis.