title: Development in the cyclic hamster of refractoriness to the superovulatory action of anti-LH serum.
abstract: Hamsters injected s.c. on the day of ovulation (Day 1) with 100 microliters equine anti-bovine LH serum ovulated 28 eggs at the end of a 5-day cycle. When a second injection of anti-LH serum was administered 4-93 days later, the animals did not superovulate and had normal 4-day cycles. Injection of 100 microliters normal rabbit serum (NRS) on Day 1 followed 14 days later by anti-LH serum resulted in the ovulation of 32 ova whereas a priming injection of 100 microliters normal horse serum (NHS) followed by anti-LH serum resulted in the ovulation of only 18 ova. When hamsters were injected on Day 1 with anti-LH serum, NHS or NRS and then with anti-LH serum in the 4th cycle, high titres of free antibodies to LH were present on Days 2-4 only in the animals treated with NRS; these hamsters ovulated a mean of 35 ova. These experiments suggest that the hamster rapidly forms antibodies to equine immunoglobulins, thus preventing a second injection of anti-LH serum from inducing superovulation.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D006224:Cricetinae; D004971:Estrus; D005260:Female; D007106:Immune Sera / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000276:immunology* / Q000502:physiology; D008647:Mesocricetus; D010060:Ovulation; D010062:Ovulation Induction; D011247:Pregnancy; D013480:Superovulation
chemical_list: D007106:Immune Sera; D007986:Luteinizing Hormone