Relationship of smoking cessation and nicotine gum use to salivary androstenedione and testosterone in middle-aged men

Cross-sectional studies have associated cigarette smoking in men with elevated androstenedione and little net effect on other sex steroids. However, it is not clear if such findings reflect the impact of nicotine exposure or if sex hormone levels change following smoking cessation. The relationship of the reported number of cigarettes smoked per day and salivary cotinine to salivary testosterone and androstenedione was examined in 221 men aged 35 to 59 years at baseline and 1 year following randomization into a clinical trial including a smoking-cessation intervention. At baseline, salivary cotinine was related to increased salivary androstenedione and testosterone following control for age, body mass, alcohol intake, and time of day of specimen collection (partial r = +.14 and +.30 P < .05 and .01, respectively). The reported number of cigarettes smoked per day was unrelated to either hormone. At the first annual visit, there was a significant decrease in the salivary androstenedione of men who had quite smoking and were currently using nicotine gum (94 v 60 pg/mL, P < .05, n = 34) and of men who had quit smoking and were not exposed to nicotine (86 v 56 pg/mL, P < .05, n = 48), whereas the salivary androstenedione of men who remained smokers at the first annual visit was unchanged (83 v 85 pg/mL, n = 139). Salivary testosterone levels were not significantly affected by a change in smoking status.(ABSTRACT TRUNCATED AT 250 WORDS)

Melatonin and puberty in female lambs exposed to EMF: a replicate study

In an earlier study, we found no effects of 60 Hz electric and magnetic fields (EMF) from a 500 kV transmission line on serum melatonin patterns or on puberty in ten female Suffolk lambs (Ovis aries). We conducted a larger replicate study of 15 lambs exposed to a mean electric field of 6.3 kV/m and a mean magnetic field of 3.77 muT and 15 controls exposed to EMF two orders of magnitude weaker than in the line area. The replicate produced essentially the same results as our previous study.

Acute administration of a 3 beta-hydroxysteroid dehydrogenase inhibitor to rhesus monkeys at the midluteal phase of the menstrual cycle: evidence for possible autocrine regulation of the primate corpus luteum by progesterone

Colocalization of progesterone receptors and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD), a key enzyme in progesterone biosynthesis, in macaque luteal cells suggest that progesterone has an autocrine role in the regulation of primate luteal function. To test this hypothesis, we administered trilostane, a 3 beta HSD inhibitor, to rhesus macaques at the midluteal phase of spontaneous menstrual cycles to rapidly and reversibly reduce progesterone production. Animals received trilostane (600 mg/dose; treated group; n = 5) or vehicle (control group; n = 4) orally on days 6-7 of the luteal phase. Trilostane significantly (P < 0.05) elevated pregnenolone levels within 1 h of treatment compared to those in vehicle-treated animals; after 1 day of treatment, the mean pregnenolone level (173 nmol/L) was 86-fold greater than the control value. Pregnenolone levels dropped after cessation of drug administration and became indistinguishable from control levels by day 13. Trilostane significantly reduced serum progesterone levels within 3 h of initial administration (P < 0.01), and levels remained near baseline (1.0 nmol/L) throughout the 2 days of treatment. Progesterone levels also remained low after cessation of trilostane treatment in four of five monkeys, and trilostane-treated animals experienced a shorter luteal phase than vehicle-treated animals (7.8 +/- 0.2 vs. 16 +/- 1 days; P < 0.01). Histological analysis (n = 3/group) revealed indexes of premature structural luteolysis by 4 days after the onset of trilostane administration. Exposure to trilostane had no effect on the percentage of luteal cells expressing progesterone receptors, as determined by immunocytochemistry. Serum LH levels were not different between treatment and control groups throughout the experimental period. As trilostane dramatically reduced serum progesterone and induced premature menses without major concurrent alteration in serum cortisol, we conclude that trilostane ios an effective, rapidly acting inhibitor of 3 beta HSD in the macaque corpus luteum during the midluteal phase of the menstrual cycle. Progesterone production did not typically resume after cessation of trilostane treatment despite continuing gonadotropin support luteolysis. Thus, progesterone or a related metabolite may be required to maintain the function and structural integrity of the primate corpus luteum during the normal menstrual cycle.

Individualized gonadotropin regimens for follicular stimulation in macaques during in vitro fertilization (IVF) cycles

Follicular stimulation was compared in macaques receiving sequential gonadotropin treatment which was terminated after seven, eight, or nine days depending on the time required to attain preselected criteria of follicular maturation. Although estradiol levels and follicle sizes varied, the number of follicles and oocytes/animal, oocyte nuclear maturity, IVF rates and progesterone levels during the luteal phase were similar among groups. Reducing the duration of gonadotropin treatment to individualize follicular stimulation regimens does not compromise follicle or gamete quality.

Initiation of periovulatory events in primate follicles using recombinant and native human luteinizing hormone to mimic the midcycle gonadotropin surge

The amplitude and duration of the midcycle LH surge required for periovulatory changes in the primate follicle are incompletely defined. We reported that short (4- to 14-h) LH surges were insufficient to induce periovulatory events after multiple follicular development in macaques. In contrast, an 18- to 24-h LH surge induced oocyte maturation plus granulosa cell luteinization, but did not support corpus luteum function. In this study, the periovulatory changes following LH surges of 48 h elicited using pituitary (pit) or recombinant (r) human (h) LH were compared to those after 24-h LH surge durations or after urinary hCG (u-hCG) treatment. Beginning at menses, rhesus monkeys were treated with human gonadotropins for 9 days to stimulate follicular growth. On day 10, animals (n = 3-5/group) received 1) a single injection of u-hCG [79 +/- 3 micrograms RP-1 equivalents (equiv), im], 2) two injections of pit-hLH (91 +/- 4 micrograms RP-1 equiv, im), 3) one injection of r-hLH (21 +/- 1 micrograms RP-1 equiv, im), or 4) two injections of r-hLH (21 +/- 1 micrograms RP-1 equiv). Oocytes and granulosa cells were obtained via follicle aspiration 27 h after the initial LH or hCG injection. In all groups, serum estradiol rose to similar peak levels by day 10. Circulating LH-like bioactivity was elevated for more than 48 h after u-hCG. Peak serum LH bioactivities were proportional to the administered LH doses, as determined in the in vitro bioassay. Two injections of either r-hLH or pit-hLH elicited surge levels (> 100 ng/mL) of bioactive LH for 36-48 h, whereas one injection sustained surge levels for only 18-24 h. The proportions of oocytes resuming meiosis (68-76%) were similar in all groups. Immunocytochemical staining for progesterone receptor and in vitro progesterone production by granulosa cells in all LH-treated groups were comparable to those of cells form the hCG-treated group. Peak levels of progesterone in the luteal phase were comparable in monkeys treated with two doses of pit-hLH and r-hLH (18.5 +/- 10.4 vs. 8.1 +/- 1.5 ng/mL) and approached that in u-hCG treated monkeys (39.5 +/- 18.0 ng/mL). However, progesterone levels in animals treated once with r-hLH (3.4 +/- 1.5 ng/mL) were less (P < 0.05) than those in u-hCG-treated monkeys.(ABSTRACT TRUNCATED AT 400 WORDS)

Steroid reduction during ovarian stimulation impairs oocyte fertilization, but not folliculogenesis, in rhesus monkeys

OBJECTIVE

To test the hypothesis that steroids locally modulate and may be required for normal follicular function and gametogenesis in primates, the effects of steroid reduction during gonadotropin-stimulated folliculogenesis was studied in rhesus monkeys.

DESIGN

Animals received human FSH (hFSH; days 1 to 6) and hFSH+human LH (hLH; day 7) to promote multiple follicular growth, and then received hCG (day 8) for ovulatory maturation. Four animals received trilostane (3 beta-hydroxysteroid dehydrogenase inhibitor) on days 1 to 8 or no inhibitor (controls; n = 4). Follicles were aspirated 34 hours after hCG.

MAIN OUTCOME MEASURES

Follicular growth, serum E2, P, and pregnenolone, oocyte nuclear maturity, and IVF.

RESULTS

Trilostane markedly reduced E2 to levels as low as 7% of controls throughout the follicular phase. Pregnenolone was 66-fold greater during trilostane treatment relative to controls. In both groups, P was at baseline during follicular stimulation but was reduced for 72 hours after hCG in trilostane-treated animals. Despite E2 suppression, follicular growth and oocyte nuclear maturity were unaltered by trilostane. Trilostane hindered the fertilizability of metaphase II oocytes (15%) in three of four animals compared with controls (65%). Metaphase I oocytes that required > 8 hours to complete meiosis in vitro failed to fertilize in the same three of four receiving trilostane relative to controls (31%).

CONCLUSIONS

Follicular growth and oocyte meiosis did not require high or increasing E2 levels. Levels of follicular products other than E2 may be of value in determining the progress of ovarian stimulation protocols. However, the acquisition of oocyte competence for fertilization may require steroids.

Systemic and intraluteal infusion of inhibin A or activin A in rhesus monkeys during the luteal phase of the menstrual cycle

The endocrine or local actions of inhibin-related peptides synthesized by the primate corpus luteum (CL) remain undefined. This in vivo study was designed to determine whether exogenous inhibin or activin modulates pituitary gonadotropin secretion and the functional life span of the CL during the luteal phase of the menstrual cycle. Beginning at midluteal phase of the cycle, either vehicle or 1 microgram/h of recombinant human inhibin A or activin A (n = 3-6 per treatment group) was infused into rhesus monkeys via the jugular vein (i.e., peripheral infusion) or directly into the CL (i.e., intraluteal infusion) by means of an osmotic minipump for 7-14 days. Daily samples of saphenous venous serum were assayed for estradiol (E) and progesterone (P) content by RIA, and for FSH and LH levels by bioassay. Intraluteal infusion of inhibin or activin did not alter circulating P levels or the length of the luteal phase compared to those values in vehicle-infused controls. Likewise, LH levels were not different between the three groups. However, FSH levels declined progressively during inhibin infusion to 26% of pretreatment levels (p < 0.05), whereas FSH levels in vehicle-infused controls were unchanged for several days and then rose (p < 0.05) to peak levels around menses. FSH levels did not change significantly during activin infusion into the CL. Although similar results were obtained in monkeys receiving peripheral or intraluteal infusions of inhibin, events following the peripheral infusion of activin were markedly different from those during intraluteal administration.(ABSTRACT TRUNCATED AT 250 WORDS)

The Brown Norway rat as a model of male reproductive aging: evidence for both primary and secondary testicular failure

In man, aging is associated with both primary and secondary testicular dysfunction. In contrast, most studies in male rat models of aging have demonstrated only secondary testicular failure. We previously reported that testes from aging male F344 rats secrete excessive progesterone (P), which may suppress gonadotropin secretion and confound aging studies. To determine whether the male Brown Norway (BN) rat is a more suitable aging model, trunk blood was collected from intact (sham-operated) and orchidectomized young (3 mo), middle-aged (13 mo), old (23 mo), and senescent (28-30 mo) animals. Testosterone (T), estradiol (E2), P, prolactin (PRL), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were measured by RIA. In intact rats, T levels declined with aging, while LH was unchanged, and FSH increased progressively with aging. In contrast to F344 rats, no age-related increases in P or E2 occurred, nor did PRL or other steroid hormones increase. In the absence of testicular feedback (orchidectomized rats), FSH and LH declined progressively with aging. These findings suggest that, as in men, aging male BN rats manifest both primary and secondary testicular failure, and do not exhibit decreased gonadotropin levels secondary to excessive steroid or PRL secretion. Therefore, the BN rat appears to be the best available rat model for studies of male reproductive aging.

Fetectomy alters maternal endocrine and uterine activity rhythms in rhesus macaques during late gestation

OBJECTIVE

The current study was designed to test the hypothesis that fetectomy will eliminate or substantially alter rhythms in maternal estradiol concentrations and subsequently reduce or eliminate uterine activity rhythms.

STUDY DESIGN

Six rhesus macaques underwent surgery for catheter implantation between days 117 and 122 of gestation (term = 167 days). At surgery the fetuses were removed and the membranes and placenta remained intact. Thirteen additional catheterized pregnant animals served as controls. Maternal arterial blood samples were collected for hormone analysis at 3-hour intervals for 24 hours, starting at 9 AM. This sampling protocol was performed four times at weekly intervals until 151 to 157 days' gestation.

RESULTS

A significant rhythm (p < 0.01) in estradiol was determined in the control animals with peak concentrations observed in the morning hours whereas the progesterone peak was observed at night. In the fetectomy group mean plasma estradiol concentrations decreased significantly from 312 +/- 34 to 110 +/- 8 pg/ml throughout the study (p < 0.01). Despite a trend toward elevated morning levels, the estradiol rhythm was ablated. The uterine contractile rhythm observed in the control animals with peak activity between 10 PM and midnight (p < 0.01) was also ablated after fetectomy. Basal concentrations of progesterone were significantly lower than control values.

CONCLUSIONS

(1) Fetectomy resulted in the elimination of the maternal estradiol rhythm. (2) The uterine activity rhythm was lost after fetectomy. These data suggest that the fetus, by supplying precursors of estrogen, may play an indirect role in the regulation of maternal estradiol rhythms, which in turn appear to play a key role in regulating uterine activity rhythms.

Melatonin secretion and puberty in female lambs exposed to environmental electric and magnetic fields

This study determined whether chronic exposure of female lambs to the electric and magnetic fields (EMF) of a high voltage transmission line can alter pineal secretion of melatonin and the normal occurrence of puberty. Twenty female Suffolk lambs were assigned randomly in equal numbers to a control and a treatment group. Treatment from 2 to 10 mo of age consisted of continuous exposure within the electrical environment of a 500-kV transmission line (mean electric field 6 kV/m, mean magnetic field 40 mG). Treated lambs were penned directly beneath the transmission line; control lambs were maintained in a pen of similar construction 229 m from the line where EMF were at ambient levels (mean electric field < 10 V/m, mean magnetic field < 0.3 mG). Melatonin was analyzed by RIA in serum of blood samples collected at 0.5-3-h intervals over eight 48-h periods. To assess attainment of puberty, serum concentrations of progesterone were determined by RIA from blood samples collected twice weekly beginning at 19 wk of age. Concentrations of circulating melatonin in control and treated lambs were low during daylight hours and increased during nighttime hours. The characteristic pattern of melatonin secretion during nighttime (amplitude, phase, and duration) did not differ between control and treatment groups. Age at puberty and number of subsequent estrous cycles also did not differ between groups. These data suggest that chronic exposure of developing female sheep to 60-Hz environmental EMF does not affect the mechanisms underlying the generation of the circadian pattern of melatonin secretion or the mechanisms involved in the onset of reproductive activity.

Chorionic gonadotropin, estradiol, and progesterone levels in baboons (Papio anubis) during early pregnancy and spontaneous abortion

The purpose of this study was to sequentially characterize peripheral chorionic gonadotropin (CG), estradiol (E2), and progesterone (P) profiles during early pregnancy in the baboon (Papio anubis). Ten pregnant baboons were bled sequentially at eighteen time points between Days 8 and 128 of gestation. In addition, blood was obtained at corresponding time points from 5 spontaneously aborting baboons. CG levels were assessed in a mouse Leydig cell bioassay using rhesus pituitary LH as the standard E2 and P levels were measured by RIA. Pregnancy-associated CG activity was detectable by Day 15 (901.4 +/- 275.6 ng/ml), peaked at Day 27 (53,494.1 +/- 14,995.6 ng/ml), and then returned to baseline values by Day 51 (45.4 +/- 8.9 ng/ml). Mean E2 concentrations rose from 28.9 +/- 4.3 pg/ml on Day 8 to 280.6 +/- 145.5 pg/ml on Day 58 and then increased 9-fold to a level of 2436.4 +/- 928.0 pg/ml on Day 72. Mean E2 concentrations ranged between 2065.9 and 3830.9 pg/ml from Day 72 through Day 128. Mean P concentrations ranged from 7.5 to 10.2 ng/ml between Days 8 and 21, rising dramatically to 38.6 +/- 4.6 ng/ml on Day 37 prior to declining to levels that ranged from 11.1 to 17.1 ng/ml between Days 51 and 128. CG levels were low in 3 of 5 animals prior to spontaneous abortion E2 and P concentrations preceding spontaneous abortion were similar to values in uncomplicated pregnancy; however, at the time abortion was detected P concentrations in all 5 animals were 1.3 ng/ml or less.(ABSTRACT TRUNCATED AT 250 WORDS)

Preovulatory gonadotropin-releasing hormone surge in ovarian-intact rhesus macaques

The occurrence and profile of the preovulatory hypothalamic GnRH surge in relation to plasma profiles of LH and ovarian steroids, i.e. 17 beta-estradiol (E2) and progesterone (P4), were examined in ovarian intact, freely moving rhesus macaques. Nine monkeys with active ovarian cycles were each fitted with a jugular venous catheter and two push-pull cannulae directed to separate sites within the median eminence (ME). Each female was connected continuously to a tether/swivel device through which daily blood samples or frequent blood samples and ME perfusates (simultaneously at 10- to 20-min intervals for 18-24 h) were obtained without disturbing the animals. An increment in the plasma E2 level (> 150 pg/ml) during the follicular phase (FP) was selected as the preovulatory ovarian signal and served as the index for initiating the ME push-pull perfusion (PPP). Daily increased P4 concentrations of more than 1 ng P4/ml plasma for several consecutive days were consistent with the assumption of ovulation and subsequent formation of a corpus luteum after PPP. A total of 18 PPP trials were completed; each in a fresh ME site. Five of these PPPs were performed during the mid- and late FP (3 were between 6-8 days before and 2 were 4 days before the E2 peak). The remaining 13 PPPs, each of 18- to 24-h duration, were performed between 24 h before and 48 h after the highest daily plasma E2 level, i.e. time zero. Of these 13 PPPs, 2 started within 12 h before (-12 to 0 h), 8 began within 12 h after (0-12 h), and 3 started between 12-24 h after this peak E2 value. During the FP, mean levels of GnRH and LH were less than 2 pg/ml and 20 ng/ml, respectively. During the periovulatory interval (-24 to 48 h around time zero), the release of hypothalamic GnRH (expressed in picograms per ml) increased to 6.63 +/- 2.35 between -12 to 0 h (n = 2), peaked at 20.70 +/- 6.09 between 0-12 h (n = 10), declined to 3.25 +/- 1.39 between 12-24 h (n = 11), and further declined to 0.89 +/- 0.18 between 24-36 h (n = 3). The mean GnRH value from 0-12 h was higher (P < 0.05) than other means (including those during the FP), except for the value between -12 to 0 h. Changes in mean plasma LH values during the same periods paralleled those in GnRH.(ABSTRACT TRUNCATED AT 400 WORDS)

Human recombinant activin-A alters pituitary luteinizing hormone and follicle-stimulating hormone secretion, follicular development, and steroidogenesis, during the menstrual cycle in rhesus monkeys

Activin, a stimulator of pituitary FSH secretion in nonprimate species, may also act in the ovary to modulate follicular development. To examine whether activin has similar actions in primates, female rhesus monkeys (n = 3/treatment) exhibiting regular menstrual cycles received sc injections of either vehicle or 60 micrograms/kg recombinant human activin-A at 0800 and 1600 h for 1 (acute) or 7 (chronic) days beginning in the early follicular phase. The vehicle-treated monkeys displayed menstrual cycles of normal length, with the follicular (11.3 +/- 1.3 days, mean +/- SE) and luteal (16.6 +/- 1.8 days) phases demarcated by midcycle peaks in serum estradiol (E) and bioactive LH. After the first activin injection, levels of human activin A peaked at 90 ng/mL within 1 h and returned to baseline before the second injection 8 h later. Although serum E and FSH levels did not change, LH increased (273%, P < 0.05) within 8 h. Acute activin treatment increased (P < 0.05) serum E within 24 h to levels (1290 +/- 330 pmol/L) typically observed at midcycle. With chronic treatment, serum E peaked on day 2 (2580 +/- 338 pmol/L; P < 0.05), then declined and rose to a second peak (1680 +/- 279 pmol/L) on day 5. During chronic activin treatment, LH levels peaked on day 2 (603 +/- 270 ng/mL; P < 0.05 compared to day 0, 15 +/- 7 ng/mL) whereas FSH increased progressively until day 5 (937 +/- 320 ng/mL; P < 0.05 compared to day 0, 169 +/- 59 ng/mL). After acute or chronic activin, the expected midcycle rises in serum E and gonadotropins were delayed to greater than or equal to day 20 (n = 4) or did not occur before menses (n = 2). Although an enlarged ovary with one greater than or equal to 4-mm follicle was observed by laparoscopy during the late follicular phase in vehicle-treated monkeys, medium-to-large follicles were not visible on ovaries during chronic activin treatment or later at the expected midcycle interval in activin-treated monkeys. Similar hormonal and ovarian events were obtained after activin treatment of amenorrheic monkeys having serum FSH, LH, and E levels that were comparable to those at menses in spontaneous menstrual cycles. Thus, exogenous activin stimulates pituitary LH and FSH secretion and ovarian estrogen secretion during the early follicular phase in intact monkeys. However, acute or chronic activin treatment did not promote complete follicular development and disrupted subsequent events in the menstrual cycle.(ABSTRACT TRUNCATED AT 400 WORDS)

Serum concentrations of oestradiol and progesterone and frequency of sexual behaviour during the normal oestrous cycle in the snow leopard (Panthera uncia)

Serum oestradiol and progesterone concentrations were measured at weekly intervals for six months, and correlated with daily behavioural observations in two adult female snow leopards (Panthera uncia). Three oestradiol peaks (> 21 pg ml-1; interval 3.6 weeks) were identified in a snow leopardess housed alone (two more were probably missed because of the weekly sampling schedule), and three oestradiol peaks were identified in a snow leopardess housed with a male as a breeding pair (interval 6 weeks). Daily frequencies of feline reproductive behaviour averaged 1.77 observations per observation period during weeks of high oestradiol and 0.62 during weeks of low oestradiol. Progesterone concentrations did not rise above baseline values (< 2 ng ml-1) in the isolated animal, but 6 weeks of high progesterone concentrations (4.9-38.8 ng ml-1) was recorded in the paired snow leopardess following mating. No offspring were produced. Snow leopards were observed daily for an additional 4.5 years. Sexual behaviour peaks could be clearly identified from December through April, and average daily sexual behaviour scores were higher during these months than during the rest of the year. Intervals between sexual behaviour peaks for the isolated snow leopardess averaged 3.03 weeks. The sexual behaviour of the paired snow leopards decreased for 8-9 weeks following mating when no offspring were produced, and decreased for 13 weeks in one year when a single cub was born.

The relationship between hCG and relaxin secretion in normal pregnancies vs peri-implantation spontaneous abortions

OBJECTIVE

We determined the ovarian response to human chorionic gonadotrophin (hCG) in terms of relaxin and progesterone secretion during the peri-implantation period of normal and failing pregnancies. We wished to test the hypotheses that relaxin production in failing pregnancies is different from that in normal pregnancies, that relaxin is a reliable, quantitative indicator of the biological activity of endogenous hCG, and that relaxin is a useful predictor of peri-implantation spontaneous abortions.

DESIGN

Daily blood samples were collected in a prospective longitudinal study from insemination patients.

PATIENTS

Women undergoing artificial insemination in natural cycles with non-frozen donor semen at a University clinic.

MEASUREMENTS

Serum LH, hCG, relaxin and progesterone were measured and the relationship between hCG and the ovarian hormones was evaluated in the peri-implantation period of normal pregnancies and spontaneous abortions.

RESULTS

Nine of 23 conceptive cycles resulted in a spontaneous abortion between 16 and 70 days after the LH peak. In all normal and failing pregnancies there was a close qualitative relationship between hCG secretion and relaxin production. Six of nine failing pregnancies were associated with abnormally low hCG secretion. Six of the spontaneous abortions were associated with rates of relaxin secretion which were higher than the mean of 14 normal pregnancies. No such alterations in progesterone concentrations were observed. In cases where hCG was extremely low, the quantitative relationship between hCG and relaxin was different from that in cases of normal hCG concentrations.

CONCLUSIONS

There is a close temporal relationship between the secretion of trophoblastic hCG and ovarian secretion of relaxin in the peri-implantation period of normal and failing pregnancies. In failing pregnancies there is substantial variability in the quantitative relationship between relaxin and hCG, indicating that relaxin is not a reliable quantitative indicator of hCG bioactivity. Contrary to previous reports, relaxin concentrations in failing pregnancies tended to be higher than or equal to concentrations in normal pregnancies until the loss was imminent. Because of this relaxin is not a useful predictor of peri-implantation spontaneous abortions.

Chlamydia in the neonate

Chlamydia trachomatis infections are the most prevalent of all sexually transmitted diseases and can be transmitted to the neonate during the birth process. Neonatal chlamydial infections include inclusion conjunctivitis and chlamydial pneumonia. These infections cause no reported mortality but are associated with a high incidence of morbidity in the newborn. Nursing care is vitally important in prevention, early detection, and management of neonates with chlamydial infections. A knowledge of Chlamydia, its risk factors, clinical manifestations, diagnosis, and treatment will assure an improved outcome for the entire neonatal population.

Administration of an aromatase inhibitor during the late follicular phase of gonadotropin-treated cycles in rhesus monkeys: effects on follicle development, oocyte maturation, and subsequent luteal function

Local modulation of follicular and gametogenic functions by ovarian androgens and estrogens in mammalian species has been proposed. This study examined the effects of elevated androgen/estrogen ratios during follicular maturation in vivo by inhibiting aromatase activity in rhesus monkeys. To obviate steroid feedback effects, gonadotropin-treated animals were used. Beginning at menses (day 1), animals received human (h) FSH (60 IU/day, im) on days 1-6, followed by hFSH plus hLH (60 IU/day, im) on days 7-9 to promote the growth of multiple follicles. Ovulatory maturation was induced by hCG (1000 IU, im) on day 10. On days 8-10, four animals received an aromatase inhibitor, 1,4,6-androstatrien-3,17-dione (ATD; 1-1.25 g, orally, twice/day), while five served as controls and received no further treatment. Within 8 h of ATD treatment, a 63% reduction in serum estradiol levels relative to control values was evident, which reached maximal suppression (84%) by day 10. A marked elevation (17-fold) in serum androstenedione and a lesser increase (2.6-fold) in serum testosterone occurred with aromatase inhibition, yielding androstenedione/estradiol (18.0) and testosterone/estradiol (1.9) ratios greater than those in controls (0.6 and 0.3, respectively). ATD treatment did not alter follicular diameters or the total number of follicles per animal (20 +/- 3) relative to control values (16 +/- 3). Of the total cohort classified, the proportion of oocytes collected at prophase I was greater (P < 0.05) after ATD treatment (31%) than in controls (11%). Completion of oocyte meiosis to metaphase II was retarded (P < 0.05) in ATD-treated (4%) compared to control (26%) animals. Furthermore, the in vitro fertilization rate of metaphase II oocytes from ATD-treated animals (9%) was reduced (P < 0.05) relative to that in controls (25%). While basal progesterone production by luteinizing granulosa cells in vitro was similar between groups, the addition of hCG in vitro enhanced progesterone secretion by cells from ATD-treated animals (3.1 +/- 0.3-fold over basal) to a greater extent (P = 0.05) than in controls (1.5 +/- 0.3-fold). Progesterone receptor was detected by immunocytochemistry in nuclei of luteinizing granulosa cells from ATD-treated animals as well as controls. Serum progesterone profiles and the length of the luteal phase were similar between groups. Thus, acute elevation of serum androgen/estrogen ratios in vivo during follicular maturation was detrimental to the gametogenic functions of the primate follicle, but did not alter follicular growth, events of early luteinization, or subsequent luteal function.(ABSTRACT TRUNCATED AT 400 WORDS)

Sex differences in adrenal function in the lizard Cnemidophorus sexlineatus: I. Seasonal variation in the field

In order to document sex differences in adrenal function and how this relates to gonadal function during the period of seasonal activity, blood samples from male and female six-lined racerunners, Cnemidophorus sexlineatus, were taken immediately after capture in the field for determination of plasma corticosterone and gonadal steroid concentrations. Plasma testosterone and dihydrotestosterone levels for males, and 17 beta-estradiol and progesterone levels for females, were measured. Trends in the concentration of plasma corticosterone differed significantly between males and females. In males the highest concentrations of corticosterone were measured in late spring and the lowest concentrations were measured in late summer. Whereas half of the variation in corticosterone levels among males could be explained as seasonal change, less than 1% of the variation among females could be explained as seasonal change. In males plasma corticosterone and androgens exhibited similar seasonal decreases. Corticosterone levels for females were not correlated with progesterone or 17 beta-estradiol levels. Sex differences in seasonal variation in plasma corticosterone concentrations suggest that corticosterone may be involved in the different reproductive strategies and energy requirements of males and females during the seasonal period of activity.

Embryotoxicity studies of norfloxacin in cynomolgus monkeys. II. Role of progesterone

Norfloxacin, an orally active fluoroquinolone antimicrobial, has been reported to be embryolethal but not teratogenic when administered to pregnant cynomolgus macaques prior to gestational day (GD) 36 at doses > or = 200 mg/kg/day. Additional studies have been performed in an effort to examine the mechanism responsible for this effect, particularly regarding the role of progesterone (P). The first study (Study I) investigated the effect of norfloxacin administration during early pregnancy (200 mg/kg/day; daily GD 20-30) in the absence of a functional corpus luteum (CL). The CL was surgically removed from 16 gravid females on GD 19 in order to focus on placental-derived P; ten were dosed with norfloxacin and six received vehicle only. Embryolethality was observed for 7/10 (70%) of the treated animals during GD 25-31 versus 0/6 (0%) for controls. A reduction in serum P was noted prior to embryonic loss, although no significant effects on chorionic gonadotropin (CG), 17 beta-estradiol (E2), or P or E urinary metabolites were observed. A second study (Study II) was performed in order to evaluate the capacity of norfloxacin (200 mg/kg) to reduce CL-derived P in both normally cycling and CG-stimulated nonpregnant females (ten treated, ten controls; daily for 8 days). No effects on P production or on luteal phase or menstrual cycle lengths were observed. The third study (Study III) was designed to examine the effect of norfloxacin on the metabolism and excretion of P in nonpregnant females. Silastic P implants were placed subcutaneously in order to maintain constant P levels during a 10 day treatment regimen (200 mg/kg/day; ten controls, nine treated). Five of the controls and four of the norfloxacin-treated females also received 14C-P intravenously within 1 hr of the last dose of norfloxacin in order to study excretory patterns. No significant differences between control and treated groups were observed. The results of these studies combined suggest that the developmental toxic effects observed in prior studies and Study I are specific to pregnancy and directly related to placental-derived P production.

Sex differences in adrenal function in the lizard Cnemidophorus sexlineatus: II. Responses to acute stress in the laboratory

Circulating concentrations of plasma corticosterone and gonadal steroids were measured in intact and gonadectomized male and female lizards (Cnemidophorus sexlineatus) following acute stress (handling) in the laboratory. There was a significant increase in plasma corticosterone after stress. Whereas intact females exhibited greater concentrations of corticosterone relative to intact males, ovariectomized females exhibited lower concentrations of corticosterone relative to castrated males. In addition to sex differences in corticosterone responses to gonadectomy, progesterone was elevated by stress in both intact and ovariectomized females but not in males. Corticosterone adjusted for castration and handling in males was negatively correlated with the plasma androgen level. The adrenal responsiveness of males to acute stress may be attenuated by androgens presumably secreted by the testis. Not only does adrenal function influence reproduction, but adrenal responses differ between males and females, and appear to be influenced by the gonadal axis. The sex differences in adrenal responses to stress likely reflect different reproductive strategies and nutritional requirements of males and females during the breeding season.

Influence of corpus luteum age on the steroidogenic response to exogenous human chorionic gonadotropin in normal cycling women

OBJECTIVE

The null hypothesis of this study is that the patterns of steroid secretion exhibited by the human corpus luteum in response to exogenous human chorionic gonadotropin stimulation are independent of corpus luteum age at the time of treatment.

STUDY DESIGN

Twenty-five normally cycling women in whom the midcycle urinary luteinizing hormone surge (luteal day 0) was identified and from whom blood samples were obtained daily from cycle day 11 until menses were prospectively randomized to receive no treatment (group I, n = 5) or exogenous human chorionic gonadotropin 5000 IU administered intramuscularly on luteal day 0 (group II, n = 5), +4 (group III, n = 5), +8 (group IV, n = 5), or +12 (group V, n = 5). Serum concentrations of estrone, estradiol, progesterone, 17-hydroxyprogesterone, and androstenedione were measured by specific radioimmunoassays in all subjects; serum human chorionic gonadotropin concentrations were determined by immunoradiometric assay in treated subjects.

RESULTS

Serum human chorionic gonadotropin levels (mean +/- SEM) were virtually identical among treatment groups (p greater than 0.05). Luteal phase duration (mean +/- SEM) was prolonged (p less than 0.05) only in group V (18.4 +/- 0.5 days) compared with untreated subjects (group I 13.8 +/- 0.7 days). In all groups estrone and 17-hydroxyprogesterone concentrations closely paralleled those of estradiol and progesterone, respectively. Steroid data and progesterone/estradiol ratios (mean +/- SEM) in groups I and II were indistinguishable and were combined (control, n = 10). Group III subjects exhibited patterns of steroid secretion similar to groups I and II, although progesterone was moderately increased after human chorionic gonadotropin treatment. In groups IV and V, progesterone increased (p less than 0.05) 1 day after human chorionic gonadotropin and remained elevated for 5 to 6 days; a 4-day rise (p less than 0.05) in estradiol began 3 days after treatment, and androstenedione rose modestly in parallel. Progesterone/estradiol ratios in groups III through V increased (p less than 0.05) approximately twofold after human chorionic gonadotropin treatment and remained elevated for 4 to 5 days.

CONCLUSION

The human corpus luteum exhibits distinct age-dependent patterns of steroid secretion in response to exogenous human chorionic gonadotropin stimulation, an observation that may have clinical implications regarding the empirical use of exogenous human chorionic gonadotropin in support of luteal function.

Excessive testicular progesterone secretion in aged male Fischer 344 rats: a potential cause of age-related gonadotropin suppression and confounding variable in aging studies

Previous studies have inconsistently reported elevated sex steroid levels in aging male F344 rats, which frequently develop testicular Leydig cell tumors. The aims of this study were to characterize circulating steroid levels and to determine the in vivo source and functional significance of altered steroid secretion in these animals. Progesterone (P) and to a lesser extent estradiol (E2) levels were increased, while gonadotropins and testosterone (T) were decreased, in intact 24-mo-old compared to 12-mo-old rats. P levels were inversely correlated with gonadotropins and T. All old rats demonstrated Leydig cell hyperplasia or tumors. After orchidectomy, P levels were markedly decreased. Gonadotropin levels were similar in orchidectomized 24-mo compared to 3-mo-old rats. We conclude that the testis is the source of excessive P and E2 secretion in vivo in old F344 rats. Increased P (or E2) negative feedback may contribute to the suppression of gonadotropins and reproductive function in aging male F344 rats. Finally, excessive P secretion may be a confounding pathological variable in aging studies using this rat model.

The Sulawesi Crested Black Macaque (Macaca nigra) menstrual cycle: changes in perineal tumescence and serum estradiol, progesterone, follicle-stimulating hormone, and luteinizing hormone levels

Events in the normal menstrual cycle of the endangered Sulawesi Crested Black Macaque (Macaca nigra) were characterized. Daily blood samples were obtained during 10 menstrual cycles from five M. nigra demonstrating regular cycles. The amount of perineal tumescence was scored daily. Serum levels of estradiol and progesterone were determined by RIA, serum LH levels were determined by the mouse Leydig cell bioassay, and serum FSH levels were determined by the rat granulosa cell aromatase bioassay. Cycle length was 39.8 +/- 1.0 days (mean +/- SEM) with an LH surge occurring 25 +/- 1.5 days from the onset of menses. After menses, both LH and estradiol were initially depressed, with estradiol first exceeding 50 pg/ml 8 days before the LH surge. In five cycles, peak estradiol levels (340 +/- 44 pg/ml) occurred on the day of the LH surge (637 +/- 58 ng/ml) and in the other five cycles, on the day before the LH surge. There was a broad increase of FSH in midcycle without a well-defined surge corresponding to the LH surge. Progesterone began increasing on the day of the LH surge and reached peak levels (6.8 +/- 0.96 ng/ml) 8 days later. Maximal perineal tumescence was generally associated with the time of the LH surge, but variation between animals made it impossible to predict accurately the day of the LH surge by perineal tumescence scores alone.

Circadian myometrial and endocrine rhythms in the pregnant rhesus macaque: effects of constant light and timed melatonin infusion

Six chronically catheterized rhesus macaques maintained on a 12-hour-light/dark cycle (lights on from 7 AM to 7 PM) showed a nocturnal uterine activity rhythm with peak contractile events between 9 and 11 PM (p less than 0.05). In blood samples collected at 3-hour intervals over a 24-hour period, we determined that plasma melatonin and progesterone concentrations were elevated at night whereas estradiol, estrone, and cortisol reached peak concentrations in the early morning (p less than 0.05). Lights were then left on for the remainder of the study. After 12 days in constant light, daily rhythms in uterine activity and plasma steroid levels were relatively unchanged, whereas melatonin concentrations were suppressed. Animals then received a timed infusion of melatonin (0.2 mg/kg/hr each day from 7 PM to 6 AM daily until delivery). The nocturnal uterine activity rhythm and the rhythms in plasma steroid concentrations were maintained. We conclude that the 24-hour patterns in maternal uterine activity and plasma steroid hormone levels are circadian rhythms generated by an endogenous biologic clock and do not appear to be driven by the pattern of melatonin in circulation.

Reproductive hormone levels after pituitary allograft in cyclosporin-treated monkeys

OBJECTIVE

To determine the course of events during the onset of hyperprolactinemic amenorrhea, a nonhuman primate model was sought that did not require suckling or interference with the in situ hypothalamic-pituitary axis.

DESIGN

Because removal of the adenohypophysis from hypothalamic influence results in secretion of large quantities of prolactin (PRL) but little of the other adenohypophyseal hormones, we explored the possibility of establishing pituitary allografts in monkeys. Normally cycling female rhesus monkeys were immunosuppressed with a daily regimen of cyclosporin A (CyA; 10 to 15 mg/kg per day) and then subcutaneously grafted with a pituitary from another animal (allograft). Blood samples were obtained daily via saphenous vein puncture during control, only CyA-treatment, and allografted-plus CyA- menstrual cycles.

SETTING

Oregon Regional Primate Research Center, Beaverton, Oregon.

PARTICIPANTS

Female Macaca mulatta exhibiting regular menstruation.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Prolactin, luteinizing hormone (LH), estradiol (E2), and progesterone (P) levels were determined in harvested serum.

RESULTS

Temporary survival of 5 of 11 (45%) allografts was assumed based on elevations in serum PRL. Of the viable grafts, 4 of 5 (80%) resulted in reproductive dysfunction, as first evidenced by delay or loss of the preovulatory rise in E2. When the peak of follicular E2 was delayed, then the LH surge occurred, but it was also delayed. If follicular E2 levels did not peak, then the LH surge was absent as was luteal P production.

CONCLUSION

These data suggest that in the etiology of PRL-induced infertility in women, the first event is a suppression of follicular E2 production. In addition, the hypothalamus probably remains responsive to the positive feedback of E2 during early or moderate hyperprolactinemia.