Effect of neonatal pineal ablation on estradiol receptors in mammary glands of rats housed under varying photoperiods.

Estradiol receptors (ER) in mammary glands of female Holtzman rats, either intact or neonatally pinealectomised and housed in 10:14 or 24:0 L:D (light:dark) schedule were studied at 30, 40, 50 +/- 5 and 65 +/- 5 days of age. Whereas ER were detectable only at the age of 60-65 days in intact rats housed in 10:14 L:D, they were present as early as 30 days onwards in the pineal ablated group. In the 24:0 L:D pinealectomised group, though mammary gland ER were maximum around 40 days of age and temporarily undetectable around day 50, they had stabilized around the age of 60-65 days. The data demonstrates for the first time, the modulation of ER in rat mammary glands in response to varying photoperiods as well as pineal ablation. Earlier reports on incidence of chemically induced mammary tumours have been compared to the receptor modulation.

Effect of vitamin C deficiency and excess on the liver: a histopathological and biochemical study in guinea pigs fed normal or high cholesterol diet.

When guinea pigs were kept on a restricted vitamin C intake of only 0.5 mg daily, their serum ascorbic acid fell to 0.16 +/- 0.06 mg/d1 in 16 weeks as compared to 0.73 +/- 0.11 in control. This was associated with significant increase in liver cholesterol and triglycerides. When they were simultaneously challenged with a high cholesterol load, this fat accumulation was markedly exaggerated. The weight of the liver now increased by almost two-and-half times. Liver cholesterol rose to 12.90 +/- 2.63 mg/gm as compared to 3.23 +/- 0.56 mg/gm with low vitamin C alone. Histopathology showed marked distension and vacuolation of hepatocytes, focal necrosis and fibroplasia. Administration of excess vitamin C (100 mg daily) significantly countered these changes. The vitamin C-lipid relationship has important clinical bearings and liver could be an important site of vitamin C action.

Indian contribution to reproductive physiology: the last 2 decades.

The end of twentieth century is witnessing far-reaching changes in the reproductive behaviour of modern man. Population is doubling now in a record time of 30 years in some parts of the world like India. On the other hand, living-together without marriage and widespread use of contraceptives is making child bearing highly optional in the West. Technological advances in the realm of in-vitro fertilization and genetic manipulation have opened up enormous possibilities, bringing us almost on the verge of Aldous Huxley's Brave New World. It is natural, therefore, that reproduction has become an attractive area of research for physiologists. We review here some of the significant contributions made by Indians to reproduction physiology during the last 20 years (1970-1990). Considerable pruning of available material has been necessary. The emphasis sometimes was on Physiologists although their contribution may not be exactly basic physiology, and sometimes on Physiology although the contributors were not exactly physiologists.

Leucocyte and serum ascorbic acid levels in mothers and their newborn in semi-arid western India.

Leucocyte ascorbic acid (LAA) and serum ascorbic acid (SAA) have been estimated in 50 pregnant women, their newborn infants, and 14 non-pregnant women living in the semi-arid region of western India. LAA was significantly higher in the newborn as compared to their mothers, the mean values being 35.52 +/- 6.85 and 23.94 +/- 5.84 micrograms/10(8) cells, respectively (P less than 0.01). The sex and birth weight of the infant, however, did not influence its ascorbic acid status. Pregnant women had relatively lower SAA (0.81 +/- 0.22 mg/dl) and LAA (23.94 +/- 5.84 micrograms/10(8) cells) as compared to the matched non-pregnant group (1.01 +/- 0.26 mg/dl and 29.98 +/- 8.45 micrograms/10(8) cells). But despite the semi-arid, draught prone geographical region and the hemodilution which accompanies pregnancy, none of the mothers had a clearly subnormal vitamin C status.

Structural organisation within the epididymis and its functional implications.

The functional organisation of the epididymis has been studied in 20 adult albino rats. The gross divisions of Caput or head, Corpus or body, and Cauda or lower end show distinctive features which indicate functional specialisation. The Caput epididymis has strikingly tall columnar cells with a mean height of 124 mu, but little muscle tissue. It seems to be adapted as a distensible low-pressure reservoir to accomodate the testicular outflow and modify it by absorption and secretion; the prominent stereocilia (or microvilli) would favour this absorptive function. The Cauda, on the other hand, shows abundant muscle tissue around the widening duct and provides the mechanism for rapid delivery of sperms during ejaculation. The Corpus or middle part is peculiarly long and slender, accomodating only 2 or 3 ductules side-by-side. It might serve to separate the two functionally different upper and lower parts and protect the testis against any undue back-pressure. The epididymis weighed 67% of the corresponding testis, on an average. The capacity of the testis to tolerate any obstruction of the outflow tract might be related to the size and capacity of the epididymis in that species.

A correlative study of seminal biochemistry and testicular histology in infertile males.

Two androgen-dependent constituents of the seminal plasma, fructose and acid phosphatase, have been estimated in 50 infertile males along with a testicular biopsy. Azoospermics, as a group, showed a very wide range of fructose (16-600 mg%) as compared to 210-397 mg% in healthy fertile males. Oligospermics tended to have low values with a mean of 218 +/- 75.1 mg%. Acid phosphatase in the controls was 1927 +/- 164.6 K.A. unit/ml and was generally higher in the infertile groups. The state of spermatogenesis, as revealed by testicular biopsy, bore no consistent relationship with the seminal fructose or acid phosphatase. It appears that there may be no inter-relationship between the activity of the germinal epithelium and the secretion of the accessory glands and, although both are androgen-dependent, they can be affected separately by a multitude of factors in human infertility.