| Abstract: | The appearance of the uterine specific proteins following induction of ovulation in prepubertal gilts is described. 12 gilts each at 3, 4, and 5 months of age were allotted randomly to 1 of 2 treatment groups prior to induction of ovulation: 1) saline treated and 2) human chorionic gonadotropin (HCG) treated (400 IU daily from Days 12 through 16 of the induced cycle). Ovulation was induced with HCG following treatment with pregnant mare serum gonadotropin and the day of ovulation was designated as Day 1. All the gilts were laparotomized and uteri infused with phosphate-buffered saline on Day 16 to obtain uterine protein secretions. Plasma progesterone levels on Day 11 and observations made at laparotomy indicated that only 1 gilt 3 months of age failed to ovulate. The number of corpora lutea, plasma progesterone, total recoverable uterine protein, and uterine specific protein on Day 16 were markedly affected by the age of the gilt. These same characteristics, except uterine specific protein, were additionally affected by HCG treatment. Total recoverable uterine protein and uterine specific protein in saline and HCG-treated gilts at 3, 4, and 5 months of age were 6.3 and 1.5, 10.4 and 2.8; 38.8 and 15.2, 51.6 and 15.9; 20.4 and 7.7, 47.8 and 14.6 mg, respectively. Polyacrylamide slab gel electrophoresis showed that HCG-treated gilts at 3 months of age and both saline- and HCG-treated gilts at 4 and 5 months of age generally produced the purple basic protein and the complete profile of the low molecular weight acidic proteins during the induced cycle. |
