title: Effect of a rat uterine fluid endopeptidase on lysis of the zona pellucida.
abstract: The uterine endopeptidase of rats caused lysis of the zona pellucida of unfertilized rat and mouse eggs but not of fertilized rat and mouse eggs. Induction of cortical granule discharge of unfertilized eggs by treatment with boromycin and a guanidine derivative led to resistance of the zona pellucida to lysis by the endopeptidase. Lysis of the hamster zona pellucida occurred within 90 min, whatever the treatment and trypsin caused lysis of all zonae within 20 min. We suggest that after fertilization cortical granule modifies the zona pellucida to prevent digestion by the endopeptidase.
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000201:enzymology*; D006224:Cricetinae; D010450:Endopeptidases / Q000494:pharmacology*; D005260:Female; D051379:Mice; D010063:Ovum / Q000187:drug effects*; D051381:Rats; D014599:Uterus / Q000378:metabolism*; D015044:Zona Pellucida / Q000187:drug effects*; D015053:Zygote / Q000187:drug effects
chemical_list: D010450:Endopeptidases