|Vallet, Jeffrey - Jeff|
|Bartol Frank F|
|Wiley Anne A|
Submitted to: Journal of Reproduction and Fertility
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/3/1994
Publication Date: N/A
Interpretive Summary: The uterine capacity of swine limits litter size. Uterine capacity may be influenced by the extent or efficiency of neonatal uterine development. Determining factors which influence neonatal uterine development may lead to techniques which improve the development process and therefore, increase uterine capacity and litter size in swine. In this experiment, a protein previously determined to be associated with neonatal uterine development was identified as a retinol (vitamin A) binding protein-like protein. The association of secretion of this protein with initiation of neonatal uterine gland development was confirmed. Because results suggested that retinol and retinol binding protein may be involved in uterine gland development, we tested the effects of progesterone (known to stimulate uterine RBP synthesis in adults) and retinyl palmitate on production of the RBP-like protein and gland development. No effect of progesterone or retinyl palmitate treatment on secretion of the protein could be demonstrated, and equivocal effects of these agents on uterine gland development were observed, possibly due to the dosages and/or vehicle used for treatment. The retinol binding protein-like protein is the first uterine protein to be identified which may play a role in uterine gland development. These results suggest that aspects of vitamin A metabolism may be useful in affecting uterine development. Further experimentation with Vitamin A may improve uterine development and uterine capacity and therefore, litter size in swine.
Technical Abstract: Previous experiments have demonstrated that uterine secretion of several proteins changes during neonatal endometrial gland development. To determi whether one of these proteins (Mr 20,000, pI 5.5) is related to retinol binding protein (RBP), uterine tissue (60-day-old gilt) was cultured and conditioned medium was immunoprecipitated using anti-human retinol binding protein antiserum. A radioactive protein with Mr 20,000, pI 5.5 was specifically immunoprecipitated from the conditioned medium. Immunoprecipitation of uterine culture medium from 0- to 12-day-old pigs demonstrated increased secretion of irRBP by day 3. Also, on day 0-6, two molecular weight forms of irRBP (Mr 19,000 and 20,000) were observed. Uterine production of the lower molecular weight form decreased by day 9. a third experiment, gilts were treated daily with either corn oil, retinyl palmitate (1760 IU/day), progesterone (5 mg/day) or progesterone plus retin npalmitate for 14 days beginning at birth. Retinyl palmitate treatment ten to decrease (p<0.1) glandular development. Progesterone had no effect on glandular development but did increase (p<0.05) lumenal epithelial area. Neither progesterone nor retinyl palmitate treatment altered uterine protei synthesis, irRBP secretion or production of GAG. Immunohistochemistry localized RBP to lumenal and glandular epithelial cells and to myometrial cells. These results are consistent with a role for RBP in the development of the uterus during the neonatal period.