Journal of Neuroendocrinology vol:8 issue:2 pages:123-127
We have previously isolated a cleaved prolactin variant, secreted by rat pituitary cells in culture, that stimulated [3H]thymidine incorporation into DNA in gonadotrophs and thyrotrophs when added to pituitary aggregate cell cultures of 14-day-old female rats. Using synthetic peptides homologous to the new C- and N-termini of the cleavage site, we made antisera recognizing this cleaved variant without significant cross reaction with native prolactin. Addition of these antisera to pituitary aggregate cell cultures decreased [3H]thymidine incorporation into DNA in gonadotrophs and thyrotrophs but not in the other pituitary cell types. These data are further evidence that this prolactin variant, cleaved between Tyr-145 and Leu-146, may have an important role as growth regulator of the gonadotrophs and thyrotrophs in the rat pituitary.