Biomedical subjects

B C Paria

Publications and source records attributed to B C Paria.

76 records · Page 5Linked to original sources

PubMed1983

Steroid hormones and embryo development in ovariectomized hamsters.

Preimplantation embryo development was arrested at the premorula stage in hamsters ovariectomized on Day 1 of pregnancy. This effect was reversed when 500 micrograms progesterone were administered daily. Oestradiol-17 beta given alone had no significant effect on the cleavage rate or blastocyst formation, but a synergistic response was evident when a suboptimal (30 micrograms) dose of progesterone was given with 50 ng oestradiol-17 beta. Cholesterol and hydrocortisol had no effect on embryo development.

Animals↗

PubMed1982

In vitro inhibiton of trophoblast maturation and expansion of early rat blastocysts by an oestrogen antagonist.

Rat blastocyst development and expansion were studied in an in vitro culture system. Early blastocysts collected from rats on the morning of day 5 were shown to develop normally and underwent expansion when placed in bovine serum albumin supplemented culture medium for 12 h at 37 degrees C. Nafoxidine, an oestrogen antagonist, prevented embryo expansion when added to the culture medium, and it was found that if oestradiol-17 beta was added to this medium this inhibitory effect was removed and the embryos again expanded. Ethanol, used as a solvent for steroids, and cholesterol were added to the medium containing nafoxidine but the blastocysts remained unexpanded after 12 h in culture. These results suggest a need for oestrogen action during blastocyst expansion in vitro. Cultured rat blastocysts were subjected to histochemical study for acid phosphatase (ACPase) and leucylnaphthylamidase (LNAse). In unexpanded blastocysts ACPase was found to be low while LNAse activity was higher when compared with enzyme distribution patterns in expanded blastocysts.

Acid Phosphatase↗

PubMed1981

Effect of an oestrogen antagonist on implantation and uterine leucylnaphthylamidase activity in the ovariectomized hamster.

CI-628 citrate, an oestrogen antagonist, instilled into the uterine lumen of ovariectomized, progesterone-treated hamsters on Day 3 of pregnancy completely prevented implantations. Normal implantations occurred in the contralateral uterine horn which was pierced by a needle and in horns into which saline was instilled. There was less activity of lysosomal leucylnaphthylamidase in implantation sites than in inter-implantation sites and in the tissues of the CI-628 citrate-treated horns.

Animals↗

PubMed1981

Involvement of lysosomal enzymes in mouse embryo implantation: effect of the anti-oestrogen, CI-628 citrate.

Implantation of embryos was studied in mice which had bee ovariectomized on the afternoon of day 4 of pregnancy and injected intraperitoneally with a non-steroidal antioestrogen or control injection. Normal implantations were obtained in the latter mice as indicated from the positive blue-dye sites when animals were killed late in the evening of day 4. Exposure to CI-628, however, led to a significant inhibition in the number of implantations and only a small percentage of the mice exposed to the steroid antagonist showed normal implantation sites. Study of a few lysosomal enzymes in uterine tissues at the time of early embryo attachment revealed a striking change in the activity of leucyl naphthylamidase. The enzyme showed a reduction in its activity only in uterine which contained attached blastocysts. Acid phosphatase, beta-glucuronidase and non-specific esterase did not show any such implantation-specific changes in their activity patterns. A possible role of leucyl naphthylamidase in the attachment of the embryo to the wall of the uterus has been explored.

Acid Phosphatase↗