set at the maximum speed (5 x 1O s at 0C). The receptor preparation was suspended at a concentration of 2 g in 10 ml of assay buffer (0.05 M, Tris-buffer, pH 7.5, containing 0.1 % BSA, 5 mM MgCI2 and 0.1 M sucrose).The testicular receptors were obtained from immature (21-day-old) Holtzman rats (Reichert & Abou-Issa, 1977). The receptor preparations were suspended at a concentration of I g in 10 ml in the assay buffer.Human FSH (hFSH-13) was iodinated by the chloramine-T method (Reichert & Bhalla, 1974) with a specific activity of about 15 tCi yg-'.Binding studies were performed using labelled hFSH (5 ng hFSH in 50 d l assay buffer) in the presence of serial dilutions of unlabelled FSH (I -250 ng) with 50 mg of testicular receptor in 500 gl of assay buffer. The total reaction volume was made up to I ml by addition of assay buffer. The tubes were then incubated in a metabolic shaker at 37°C for 2 h. Incubation was terminated by addition of 2 ml of chilled buffer. The tubes were then centrifuged at 1,500g for 15 min. The supernatant was discarded by decantation and the tubes were drained and counted in the well type gamma-counter. The non-specific binding was determined in presence of a 1000-fold excess of oFSH (NIH-FSH-S-16).

To study the sperm chromatin compactness various methods, such as acidic aniline blue or acridine orange staining, have been applied. Due to its metachromatic properties, acridine orange dye fluoresces green with double- and red with single-stranded DNA. Samples (n = 181) were evaluated and grouped as follows: group I, normal recently fertile; group II, male having female partner with repeated early pregnancy loss; group III, male with varicocele; and group IV in-vitro fertilization and intrauterine insemination failures. Routine semen analyses were carried out in all the cases. Amorphous particulate matter as observed under phase contrast microscope was graded on the scale of nil to +4. Fixed smears were stained with an aqueous solution of acridine orange and viewed under a fluorescence microscope. Two hundred cells were counted and the percentage of fluorescence calculated. Groups II, III and IV exhibited significantly low green fluorescence compared with the control group. The study also indicates that increased amorphous particulate matter (indicating infection) might be one of the contributing factors to lower acridine orange stainability. Thus acridine orange staining can be used to evaluate the integrity of the nucleus, disorders of which can cause unexplained infertility or lower fertilization potential that may go undetected by routine analysis.

Administration of hCG to normal healthy men caused 40 fold increase in circulating levels of inhibin at 24 hr. FSH levels decreased between 72-120 hr of hCG injection. Although, testosterone levels were maintained at higher levels during hCG therapy for more than 10 days, inhibin and FSH levels returned back to pretreatment levels, indicating involvement of hCG in the regulation of circulating levels of inhibin.

Circulatory levels of LH and FSH were measured in serum of male rats (28, 35, 42, 63, 70, 77, and 207 days of age) 7 days following sham operation, castration (C), prostatectomy (P), and castration + prostatectomy (C + P). In C + P rats that were 49, 63, 70, 77, and 207 days of age, the plasma FSH was significantly elevated as compared to the C group. Administration of aqueous prostatic extract restored the circulatory FSH level in C + P animals to that observed in C animals, whereas in C animals FSH levels were suppressed, indicating inhibinlike activity. In rats 49 and 77 days of age, circulatory LH levels were significantly suppressed in C + P animals as compared to the C group. Both castration and prostatectomy alone suppressed circulatory prolactin levels. Administration of prostatic extract to castrated animals restored the prolactin levels to that of the sham-operated control animals. Results of the present study suggest a role of the prostate in feedback regulation of FSH and prolactin.

The seasonal changes in the production of semen were investigated in four proven-fertile bonnet males (Macaca radiata), maintained under ordinary laboratory conditions. The various physical and biochemical characteristics of 190 ejaculates collected at different seasons of the year were analyzed. There were no significant changes in the responses to penile stimulation, in semen volume, sperm density, and in the concentrations of fructose, citric acid, sialic acid, maltase, amylase, and protein of seminal plasma, attributable to season.