Comparison of opioid and alpha-2 adrenergic receptor binding in horse and dog brain using radioligand autoradiography.

Objective: To test the hypothesis that the distribution, density, and subtype of opioid and alpha (alpha)-2 adrenergic receptors within the central nervous system (CNS) are significantly different between horse and dog.

Study Design: Prospective experimental study.

Animals: Three dogs (3 years of age) and three horses (2-5 years of age).

The antiestrogen ICI 182,780 abolishes developmental injury for murine embryos exposed in vitro to o,p'-DDT(1).

Previously, we reported that in vitro exposure of murine embryos to 0.1 microg/ml o,p'-DDT (an estrogenic pesticide) significantly reduced development to blastocyst and mean cell number per embryo, and increased percent cell death by 96 h of culture. The objective of the present study was to determine if developmental injury induced by o,p'-DDT resulted from estrogenic, antiestrogenic, or unrelated adverse biologic mechanisms.

Developmental alterations in murine embryos exposed in vitro to an estrogenic pesticide, o,p'-DDT.

Culturing pronuclear embryos from CD-1 mice with o,p'-DDT and p,p'-DDT was examined as a means for directly evaluating toxicant risk and for increasing the speed of screening developmental toxicants. Pronuclear (2PN) embryos from CD-1 mice were cultured 96 h in modified Earle's balanced salt solution containing 0.1% (v/v) ethanol (control) or 10-fold dilutions of 17/beta-estradiol, o,p'-DDT, or p,p'-DDT.