Daily variations of FSH, LH and testosterone response to intravenous luteinizing hormone-releasing factor (LRF) in normal men

Purification and functional characterization of a low-molecular-mass Ca2+,Mg2+- and Ca2+-ATPase modulator protein from rat brain cytosol

A low-molecular-mass modulator protein having a molecular mass of about 12 kDa has been purified from rat brain cytosol following gel filtration and FPLC/Mono Q anion-exchange chromatographic separation. A number of protein fractions were obtained from an FPLC column when eluted with a 0.1 M NaCl hold gradient. One fraction (peak no. 5) was found to stimulate Ca2+,Mg2+-ATPase but inhibit Ca2+-ATPase isolated from goat spermatozoa. The S50 (concentration producing 50% stimulation) and I50 were found to be in the nanomolar range. The modulator seems to bind to Ca2+, Mg2+- or Ca2+-ATPase at a site distal from the ATP binding site. The binding to both the ATPases is reversible and non-competitive in nature. The inhibitory activity is found to depend significantly on -SH or -NH2 group(s) of the modulator, whereas no appreciable dependency of the stimulatory effect was apparent. The study indicates that the modulator is not a glycoprotein. CD analysis suggests that the protein exists as an unordered secondary structure. An immuno-cross-reactivity study with specific antibody and inhibition by thapsigargin suggests that the Ca2+,Mg2+- and Ca2+-ATPases from goat testes microsomal membranes are two isoforms of the sarcoplasmic/endoplasmic-reticulum Ca2+-ATPase (SERCA) family. The modulator does not contain any Trp molecules, as evident from Trp fluorescence analysis. Amino acid analysis shows that glycine, serine, derivatives of tyrosine and phenylalanine are the predominant amino acids. The data suggest that the modulator is a negatively charged protein and is a good tool for distinguishing the regulation of Ca2+,Mg2+- and Ca2+-ATPase activities.

Morning to evening changes of human pituitary and adrenal responses to specific stimuli

We performed a combined stimulation test with the simultaneous application of GnRH (100 micrograms), TRH (200 micrograms) and ACTH (10 micrograms) in 10 healthy adult males at two opposite clock timing, i.e. at 09:00 and 21:00 h. Pituitary (gonadotropins, PRL, TSH) and adrenal (cortisol, aldosterone, progesterone) hormones showed a common trend of enhanced responsiveness to the evening challenge. Differences reached statistical significance in the case of cortisol, aldosterone, PRL and FSH. These findings suggest that the responsiveness of some pituitary and adrenocortical hormones to specific stimuli is physiologically different in humans as a function of the clock timing, being higher in the evening than in the morning. From the clinical standpoint, however, differences in the magnitude of responses were not enough to recommend provocative testing at a particular clock time, at least for routine diagnostic purposes.

Testicular steroid response to continuous and pulsatile intravenous luteinizing hormone-releasing hormone administration in normal men

In 18 healthy normal men Leydig cell response was examined following intravenous luteinizing hormone-releasing hormone (LH-RH) administration under standardized conditions. The same total amount of LH-RH was administered for 3 hours both in a continuous (1 microgram/min; C (1,1)) and in a pulsatile fashion, by giving a 20 micrograms dose at 20 minutes intervals, P (20, 20), and a 60 micrograms dose at 60 minutes intervals, P (60, 60). Following the different modes of LH-RH administration which all caused 3-4 fold elevations of the mean endogenous luteinizing hormone (LH) concentrations and 1.7-2 fold elevations of the mean follicle-stimulating hormone (FSH) serum levels, an overt increase of the mean testosterone (T) levels was noticed up to 1.5 X the baseline value. No difference was observed in the total amount of T release among the investigated groups. The patterns of the T response, however, clearly differed from one another with a rapid increase, during the C (1, 1) and the P (20, 20) LH-RH administration, and a delayed but persistent T increase in the P (60, 60) experiment. The mean 17-hydroxyprogesterone (17-OHP) concentrations demonstrated a similar course to T in the P (60,60) experiment, while significant increases of the oestradiol (E 2) levels were never observed in all three experiments. In view of the comparable LH and FSH increments in response to LH-RH administration in either experiment the differences in T responses may be explained by assuming a direct effect of LH-RH on Leydig cell steroidogenesis in the men.

Differential effect of luteinizing hormone-releasing hormone infusion on testicular steroids in normal men and patients with idiopathic oligospermia

Basal serum gonadotropin levels in 11 oligospermic men were significantly higher than in 9 euspermic control subjects, although most were still in the normal range. Basal serum testosterone (T), 17-hydroxyprogesterone (17-OHP), and estradiol levels and their ratios did not differ significantly. Continuous luteinizing hormone-releasing hormone (LH-RH) infusion (1 microgram/minute for 180 minutes) during integrated blood sampling evoked similar gonadotropin responses in both groups but had a differential effect on T: in the control subjects T increased (P less than 0.01) within 15 minutes to 1.5 times baseline, whereas in the oligospermic men T decreased (P less than 0.01). From 60 minutes on, however, T also significantly rose in the oligospermic men, but the maximum increment was about half lower (P less than 0.01) than in the euspermic men, despite virtually similar rises in 17-OHP. Only in the oligospermic men did the 17-OHP/T ratio increase (P less than 0.02) during LH-RH, which is compatible with the occurrence of a 17,20-lyase block. Serum estradiol did not increase in either group. In conclusion, continuous LH-RH infusion uncovers an intrinsic difference in acute Leydig cell stimulation between euspermic and oligospermic men.

Pituitary gonadotropin responses to different modes and doses of intravenous luteinizing hormone-releasing hormone administration in normal men

In 22 potentially fertile men, pituitary gonadotropin secretion was investigated by intravenous luteinizing hormone-releasing hormone (LH-RH) administration. LH-RH was administered continuously (1 microgram/minute) and in a pulsatile fashion (20 micrograms at 20-minute intervals, 20 micrograms at 60-minute intervals, and 60 micrograms at 60-minute intervals), for 3 hours, under standardized conditions. Blood was collected continuously by means of an integrated sampling technique. The mean serum luteinizing hormone (LH) concentration after any type of pulsatile administration rose significantly more than after continuous LH-RH administration. The mean increase in LH after pulsatile LH-RH administration with a 60-micrograms dose and 60-minute intervals was significantly greater than after pulsatile administration with a 20-micrograms dose and 20- or 60-minute intervals. No differences were observed in follicle-stimulating hormone responses after any type of LH-RH administration. These data confirm the existence of a self-priming effect for LH in the men; and maximum pituitary stimulation, within the dosage range tested, is reached after pulsatile LH-RH stimulation with an interval of 60 minutes.

D-Tryptophan-6-luteinizing hormone-releasing hormone in the treatment of normogonadotropic oligoasthenozoospermia

D-Tryptophan-6-LH-RH was assessed in the treatment of patients with normogonadotropic oligoasthenozoospermia in 18 subjects selected on the basis of at least 3 spermiograms, long standing infertility, normal LH, FSH, prolactin and testosterone serum levels and lack of evidence of any other pathologic involvement. Testicular biopsies performed on these patients showed hypospermatogenesis with foci of alteration at the spermatid stage in some of them. D-Trp-6-LH-RH was administered im for 90 days at a dose of 5 micrograms every 2 days, 10 micrograms daily or 10 micrograms every 2 days. There was no significant improvement in the concentration of spermatozoa or in the motility and vitality parameters. Moreover, in 5 patients who received 10 micrograms daily, basal levels of LH and FSH and the response to LH-RH, decreased significantly during treatment. D-Trp-6-LH-RH at the dose used in this study does not seem useful for the treatment of oligoasthenozoospermia normogonadotropic patients.

Effect of D-leucine-6-luteinizing hormone-releasing hormone ethylamide in patients with hypogonadotropic hypogonadism with anosmia

Four men with hypogonadotropic hypogonadism and anosmia were tested with acute intravenous injections of luteinizing hormone-releasing hormone (LH-RH) and D-leucine-6-LH-RH-ethylamide (D-L eu-6-LH-RH-EA) with a 1-week interval. Each patient was then treated with this drug for 60 days and tested again after this period with an intravenous injection of D-L eu-6-LH-RH-EA. The administration of LH-RH resulted in a significant increase in the LH level in only one patient and in follicle-stimulating hormone (FSH) and testosterone increases in none. The analog D-Leu-6-LH-RH-EA resulted in significant increases in LH levels in two patients, in FSH levels in three, and in testosterone levels in one. Results obtained after treatment were closely similar to those observed before treatment. Clinical improvement in terms of increased libido, erection, pubic hair growth, and testicular size was observed. D-Leu-6-LH-RH-EA could be useful in the treatment of patients with hypogonadotropic hypogonadism, a possibility deserving further studies.

Bromocriptine in the treatment of hyperolactinemic amenorrhea

Thirty women with secondary amenorrhea and hyperprolactinemia were studied; galactorrhea was present in 25 of them, and 18 were infertile. Serum prolactin (PRL) levels were high in all cases, between 26 and 120 ng/ml. All women were treated with bromocriptine in increasing doses from 2.5 to 5.0 or 7.5 mg daily, according to the response obtained, for 4 months. In 27 patients a PRL determination was performed during treatment; values returned to normal (up to 20 ng/ml) in 23 women and remained high in 4. Galactorrhea disappeared in 21 of 25 women. Ovulatory menses were re-established in 17 patients (56.6%). Seven women became pregnant (38.8%), one of them after bromocriptine and clomiphene were given simultaneously in the same cycle. According to our results and a literature review the following conclusions may be drawn: (1) bromocriptine is a useful therapeutic tool for re-establishing menstruation and inducing ovulation in patients with the hyperprolactinemic-amenorrhea syndrome; (2) the association of bromocriptine and clomiphene could be the next step in the treatment of patients who fail to ovulate with bromocriptine alone.

Pituitary and testicular response to LH-RH and to a long-acting analogue (D-leu-6-LH-RH-ethylamide)

The LH, FSH and testosterone response to 50 microgram i.v. LH-RH and to 2.5, 5.0, 10.0, and 20.0 microgram i.m. D-Leu-6-LH-RH-ethylamide was studied in 6 subjects with normogonadotrophic, idiopathic oligozoospermia. All injections were given between 8:00 and 9:00 a.m. at weekly intervals. Blood samples were collected before and 30 and 45 minutes after injection of LH-RH, and before and 2, 4, 6, 12, and 24 hours after D-Leu-6-LH-RH-ethylamide injections. Serum levels of LH, FSH, and testosterone were measured by triplicate by R.I.A. LH and FSH responses to LH-RH showed peak values at 30 minutes, whereas following injections of D-Leu-6-LH-RH-ethylamide, maximal values were recorded between 4 and 6 hours and were higher than those obtained with LH-RH. A significant rise of serum testosterone levels was observed after all stimuli, with peak values 45 minutes after LH-RH and 4 to 6 hours after D-Leu-6-Lh-RH-ethylamide injections. The testosterone levels obtained following LH-RH and different doses of the analogue did not differ significantly from one another. The same sequence of maximal LH and FSH values was obtained after injections of LH-RH and of D-Leu-6-LH-RH-ethylamide, particularly at doses of 10.0 and 20.0 microgram. This suggests that the gonadotrophin response to these agents would be a true reflection of the individual mode of pituitary response.

Germinal cell aplasia: response of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone to LH/FSH-releasing hormone with histopathologic correlation

Five male patients with infertility due to biopsy-proven germinal cell aplasia were given a 100-microng bolus of luteinizing hormone (LH)/follicle-stimulating hormone (FSH)-releasing hormone (LRH), and the resultant LH, FSH, and testosterone responses were correlated with their histologic patterns on testicular biopsy. The basal and stimulated FSH values were elevated in four of five patients. Basal LH values were elevated in three patients, while two clearly had exaggerated LH and testosterone responses to LRH. Although there was little correlation between various parameters, elevated basal LH values were associated with Leydig cell hyperplasia. Higher basal FSH levels were present when fibrosis and complete aplasia of germinal elements were found in the same biopsy specimen, and the magnitude of the FSH response to LRH correlated positively with the basal concentration. The findings of elevated basal LH values, an exaggerated LH response to LRH, lack of testosterone response, and Leydig cell hyperplasia indicate a definite disturbance of the LH-testosterone axis in many patients with germinal cell aplasia. Therefore, the regulation of secretion of both gonadotropins appears to be abnormal in this disorder.

Luteinizing hormone (LH), follicle-stimulating hormone, and testosterone responses to consecutive injections of D-leucine-6-LH-releasing hormone ethylamide in normal men

Luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T) responses to three consecutive intravenous injections of D-Leu-6-LH-releasing hormone ethylamide (D-Leu-6-LH-RH-EA) at 3-hour intervals were studied in six healthy, fertile, male volunteers 34.2+/-1.6 years of age. Each man received three injections of 20 microng of D-Leu-6-LH-RH-EA at 6:00 A.M., 9:00 A.M., and 12:00 noon, respectively. Blood samples were obtained before the first injection and at 1, 2, 3 (before the second injection), 4, 5, 6 (before the third injection), 7, 8 and 9 hours after the beginning of the test. Serum levels of LH, FSH, and T were determined by radioimmunoassay with the double-antibody technique. The response to the first injection of D-Leu-6-LH-RH-EA confirmed the longer duration of the stimulation of LH and FSH release caused by this compound as compared with that caused by LH-RH. Serum T levels rose significantly, almost paralleling the variations experienced with gonadotropins. The second injection caused a slight increase in LH and T responses in relation to the first injection. Two and three hours after administration, the third stimulus resulted in hormone levels lower than those obtained with the first two injections. Possible explanations for this finding might be a reduction of pituitary responsiveness as a result of multiple stimulation with D-Leu-6-LH-RH-EA, or spontaneous circadian variation of the pituitary response, or a combination of factors.

Correlation between leuteinizing hormone responses to luteinizing hormone-releasing hormone (LH-RH) and to D-leu-6-LH-RH-ethylamide in patients with hypothalamo-pituitary disease

Seventeen patients (eleven females and six males) with organic hypothalamo-pituitary disease were subjected to a test consisting of a rapid intravenous injection of 50 mug of luteinizing hormone-releasing hormone (LH-RH) at 8:00 A.M., with blood sampling before and 30 and 60 minutes afterward. Two to four weeks later, a rapid intravenous injection of 50 mug of D-Leu-6-des-Gly-10-LH-RH-ethylamide (D-Leu-6-LH-RH-EA) was given under similar conditions, with blood sampling before and 30, 60, and 90 minutes afterward. Serum LH levels were determined by radioimmunoassay. D-Leu-6-LH-RH-EA caused a greater and more sustained rise in serum LH levels than did an equal dose of LH-RH. However, functional classifications of patients were similar with either preparation. This finding suggests that acute administration of D-Leu-6-LH-RH-EA does not cause a higher number of relevant responses as compared with LH-RH, but only a greater stimulation of LH releases in responsive patients.

LH and FSH responses to luteinizing-releasing hormone in normal, adult, human males

Time-response and dose-response relationships were established for the LH and FSH response to single intravenous bolus injections of synthetic LRH. Sixteen normal adult human males, ages 19-45 were studied, and 80 individual tests were performed using a broad range of LRH doses from 0-3000 mug. Serum gonadotropins were measured at frequent intervals ranging from -30 to 180 min after LRH injection. The curves describing changes in blood LH and FSH with time were not superimposable at any dose level. The 50% decay time for the LH response showed a significant linear log-dose relationship to LRH. For LH, dose-response relationships existed for both, the peak LH release, and the total LH secretion (area under the time-response curve). No minimal or maximal effective doses were reached for LH within the dose range from 1 to 3000 mug LRH. The smallest dose (measured as peak LH concentration), that produced a response significantly different from saline injections, was 1.58 mug/subject; judged by total LH secretion (area under the time-response curve) the smallest dose producing a significant response was 2.39 mug/subject. No dose-response relationship existed for the peak FSH release. Judged by total FSH secretion (area under the time-response curve), the effects of LRH were dose related; the smallest effective dose was 20 mug LRH. As for LH, no maximal effective dose was reached within the dose range studied. The 95% confidence intervals for the peak responses to an intravenous bolus injection of 100 mug synthetic LRH were 400%-800% of the individual mean base line LH concentration, and 100%-200% of the individual mean base line FSH concentration. Serum testosterone did not change significantly in response to single bolus injections of LRH at any of the dose levels studied. The peak LH responses to any dose of LRH were positively correlated to the individual mean base line LH concentrations. No correlations were observed between the peak LH or FSH responses and age, race, marital status, body weight, or body surface area of the subjects. In a second series of studies, a 2-hr, constant infusion of synthetic LRH was administered at five different infusion rates (doses) to four normal adult human males for a total of 20 infusions. Serum LH and FSH responses were sustained at dose related levels characteristic of each individual during the entire LRH infusion period. In contrast to the lack of testosterone responses to bolus injections of LRH, serum testosterone rose significantly in response to all dose levels of LRH infusion. These are the most extensive pharmacologic studies of LRH-LH and LRH-FSH relations in man yet reported.

Luteinizing hormone and follicle stimulating hormone and the response to luteinizing hormone releasing hormone in relation to sex and age

Serum follicle stimulating hormone (FSH) and luteinizing hormone (LH) before and after intravenous injection of luteinizing hormone releasing hormone (LHRH) were studied in 71 male and female subjects of various ages. Mean basal FSH and LH levels were not significantly different in the male groups, except that FSH was significantly higher in the very old subjects. Postmenopausal female subjects had much higher concentrations of both hormones than had premenopausal women. LH was higher in female subjects shortly after the menopause than in very old female subjects. The serum concentrations of both FSH and LH 30 min. after intravenous injection of 200 mug LHRH were not different from the 60 min. values. There was no significant difference in the response of LH in the male groups. The peak FSH concentration was higher in the very old male subjects. Postmenopausal women had a much higher peak concentration of both FSH and LH than had younger subjects. The increment of LH, but not of FSH, was larger in female subjects shortly after the menopause than in very old female subjects. In both sexes there was a significant correlation between the basal FSH/LH ratio and age. In younger male subjects there was a close positive correlation between basal LH and serum testosterone, in older male subjects this correlation was negative and significant.

Treatment of idiopathic normogonadotropic oligoasthenospermia with synthetic luteinizing hormone-releasing hormone

An assessment of the effectiveness of synthetic luteinizing hormone-releasing hormone (LH-RH) in the treatment of idiopathic normogonadotropic oligoasthenospermia was made in 21 subjects selected on the basis of at least three previous sperm counts; a history of long-standing infertility; normal urinary gonadotropin excretion; normal serum levels of luteinizing hormone, follicle-stimulating hormone, and testosterone; and lack of any evidence of other clinical, endocrine, vascular, infectious, and/or urologic involvement. On testicular biopsy, 14 patients showed hypospermatogenesis or arrest up to the spermatid stage (group 1), while the remaining 7 had more severe spermatogenetic disorders (group 2). Libido and/or potency were previously unaltered in all subjects. Five patients in group 1 and five patients in group 2 received intramuscular injection of 100 to 500 mug of LH-RH daily for no less than 60 days (long-term treatment); the remainder received the drug for 30-day periods, with 30-day intervals (short-term treatment). Qualitative and quantitative assessment of the results during and after treatment showed frank improvement in spermatozoal concentration, vitality, and motility in group 1 patients, particularly in those undergoing long-term treatment (three of five patients under these conditions were able to impregnate their wives). The long-term regimen also resulted in predomantly qualitative improvements in group 2 (one of five patients impregnated his wife). The short-term regimen was less effective. Improvements under either regimen usually occurred at the end of, or after, treatment. Six of seven patients in group 1 who were followed for a long period retained values above preliminary values for 90 to 150 days after the drug was discontinued. Increased libido and potency were spontaneously reported by 15 patients, 20 to 30 days after the start of administration of synthetic LH-RH.

Response of luteinizing hormone and follicle-stimulating hormone to different doses of D-leucine-6-LH-RH ethylamide in oligospermic patients

The rise in luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels after intramuscular administration of D-leucine-6-LH-RH ethylamide was studied in seven patients with idiopathic normogonadotropic oligospermia. Four tests with 2.5, 5.0, 10.0, and 20.0 mug of the analog, respectively, were carried out at 8 A.M. on each subject. The interval between tests was 1 week. Serum levels of LH and FSH were determined by radioimmunoassay before (-15 And 0 minutes) and 2, 4, 6, 12, and 14 hours after each injection. No differences in the basal values for either hormone were observed. D-Leucine-6-LH-RH ethylamide produced significant increases in LH and FSH levels for 6 to 12 hours after the injection. Peak values were obtained between 4 and 6 hours. A dose-response relationship for both gonadotropins was observed. The highest average levels of LH and FSH were obtained after injection of 20.0 mug of the drug. A great individual variation in magnitude of response was observed which seemed to be related to the functional reserve of the pituitary. It is suggested that doses of 10.0 to 20.0 mug of D-leucine-6-LH-RH ethlamide/day could be used for chronic treatment in male infertility.