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Synthetic Neuropeptide Antagonists Stimulate in Vitro Thyrotropin and Growth Hormone Secretion by Hatchling Turtle Pituitaries by Robert J. Denver; Paul Licht is a Environmental Science article available to read on EtoBox.

The effects of synthetic antagonists to mammalian vasoactive intestinal polypeptide (VIP), corticotropin-releasing hormone (CRH), and growth hormone-releasing hormone (GHRH) on in vitro thyrotropin (TSH) and growth hormone (GH) secretion by pituitaries of hatchling slider turtles (Pseudemys scripta elegans) were investigated in hopes of understanding the mechanism(s) of action of the native neuropeptides. Pituitary glands were incubated individually in wells, and the culture medium was changed every 2 hr. After determination of basal secretion rates for one 2 hr period, glands were incubated in medium with or without VIP antagonist (100 or 500 nM) for 2 hr followed by two 2 hr periods with antagonist plus 2.5 nM VIP. VIP alone had no effect on TSH or GH secretion at this dose; however, both TSH and GH secretion were significantly elevated by the high dose of the VIP antagonist plus VIP (2.9-fold). In another experiment, glands were exposed to 2.5 kgiml(500-750 nM) antagonists to VIP, CRH, or GHRH for four 2 hr incubation periods. The GHRH and VIP antagonists stimulated significant increases in TSH secretion above basal release, whereas the CRH antagonist produced a significant stim

Author

Robert J. Denver; Paul Licht

Publisher

John Wiley and Sons; Wiley (John Wiley & Sons); John Wiley & Sons Inc.; Wiley (ISSN 0022-104X)

Published

1989

Language

EN

Field

Environmental Science (Life Sciences)