Studies in antifertility agents. 50. Stereoselective binding of d- and l-centchromans to estrogen receptors and their antifertility activity

Centchroman [dl-3,4-trans-2,2-dimethyl-3-phenyl-4-[p-(beta-pyrrolidinoethoxy)phenyl] - 7-methoxychroman hydrochloride], an antifertility agent under clinical evaluation, has been resolved into its optical enantiomers. The cytosol estrogen receptor binding affinity and estrogenic, antiestrogenic and antiimplantation activities of the two enantiomers have been determined. The enantiomers display a 7-fold difference in receptor affinity, and a corresponding difference in stimulation of the uterine growth and antiimplantation activity was observed in rats.     

Morphological changes in human spermatozoa as examined under scanning electron microscope after in vitro exposure to saponins isolated from Sapindus mukorossi

Saponins isolated from Sapindus mukorossi have potent spermicidal activity. Morphological changes in human ejaculated spermatozoa after exposure to these saponins were evaluated under Scanning Electron Microscope. The minimum effective concentration (0.05% in spot test) did not affect the surface topography after exposure for 1 minute. However, incubation of spermatozoa for 10 minutes resulted in extensive vesiculation and disruption of plasma membrane in the head region. Higher concentrations (0.1%, 1.25%, 2.5% and 5.0%) caused more or less similar changes which included vesiculation, vacuolation, disruption or erosion of membranes in the head region. These findings suggest that the morphological changes observed are due to alterations in the glycoproteins associated with the lipid bilayer of plasma membrane of spermatozoa.     

Atrial fibrillation with neonatal pulmonary lymphangiectasia

A female infant born at 28 weeks' gestation was found to have mild hydrops foetalis. Initial echocardiography showed a structurally normal heart. During the first week of life, episodic atrial tachycardia with 1:1 or 2:1 conduction was seen, requiring therapy with digoxin. The infant remained ventilator dependent, with a persistent, chylous pleural effusion which contained a preponderance of lymphocytes. Congenital pulmonary lymphangiectasia (CPL) was confirmed histologically. Worsening episodes of atrial tachycardia, including episodes of atrial fibrillation, were further investigated and a repeat echocardiogram revealed thickening of the entire right atrial wall. The cardiac findings of a thickened right atrial wall with the histological signs of myocarditis were thought to be the cause of paroxysms of atrial fibrillation, an extremely rare arrhythmia in the neonatal period. To the authors' knowledge there have been no previous reports of CPL in association with the cardiac abnormalities described herein.     

Effect of long-term centchroman treatment on some estrogen-sensitive biochemical constituents in the genital organs of female rhesus monkeys (Macaca mulatta)

Effect of long-term Centchroman (3,4,-trans-2,2-dimethyl-3-phenyl-4-p-(beta-pyrrolidinoethoxy)-phe nyl)-7-methoxy chroman) treatment on some estrogen-sensitive biochemical parameters in the genital organs of female rhesus monkey was studied. Centchroman treatment did not demonstrate any consistent pattern of stimulation or inhibition in any of the estrogen-sensitive biochemical parameters. However, glycogen recorded a gradual decline in uterus, cervix and vagina. The results thus indicate that Centchroman evoked a mixed response probably due to manifestations of both estrogenic and antiestrogenic properties.     

Estrogen receptors in rat bone: their interaction with estrogen receptor modulators.

Estrogen receptors (ER) were studied in rat bone cytosol using immunoprecipitation, and Western blot technique. Ligand specificity of bone ER was studied using various known modulators of ER. Competitive experiments were performed under exchange conditions in bone tissue obtained from one day old rats. ER alpha and beta subtypes were identified using immunoblotting experiments compared with that of ovarian and uterine tissues. In competitive binding assay, maximum inhibition in specific 3H-E2 binding was shown by E2 followed by tamoxifen and diethylstilbestrol. 7-Hydroxycentchroman and 85/287 also inhibited specific 3H-E2 binding but were less potent as compared to tamoxifen and diethylstilbestrol. However, 85/287 was less effective (81%) as compared to 7-hydroxycentchroman. Polyacrylamide gel electrophoresis of cytosol and Western blot analysis revealed the presence of 55 kD and 66 kD ER immunoreactive bands corresponding to alpha and beta subtypes, respectively, in bone as well as in uterus. Interestingly, the concentration of 55 kD ER was 3-fold higher than that of 66 kD ER. Ovarian cytosol revealed the presence of a 55 kD band only in Western blot analysis. These studies suggest the action of estrogens/ER modulators on osteoblasts which contain a limited number of classical alpha as well as beta sub types of ER that are known to be structurally different in their hormone-binding domains.