Plasma concentration of prolactin during four-day osmotic pump infusion of thyrotropin-releasing hormone and vasoactive intestinal polypeptide in rats.
Pituitary prolactin (PRL) responses to 4-day continuous infusion of thyrotropin-releasing hormone (TRH) and vasoactive intestinal polypeptide (VIP) were investigated in unanesthetized male rats using Alzet osmotic minipumps. The TRH dose infused was 3.6 micrograms/day and the VIP dose was 32.8 micrograms/day. Infusion of TRH with osmotic pumps elevated the plasma PRL level compared to controls over the 4-day infusion period. However, mean levels of PRL tended to decrease during the 4-day infusion. On the other hand, continuous VIP infusion elicited a significant continuous PRL release over the 4-day infusion period. Thus, it may be said that the PRL responses to infused TRH and VIP were maintained during the 4-day infusion.
D000818:Animals; D007263:Infusions, Parenteral; D008297:Male; D011388:Prolactin / Q000097:blood*; D051381:Rats; D011919:Rats, Inbred Strains; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D013997:Time Factors; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D014660:Vasoactive Intestinal Peptide; D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin