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Horm Metab Res 1985; 17(6): 293-297
DOI: 10.1055/s-2007-1013522
ORIGINALS
Basic
© Georg Thieme Verlag, Stuttgart · New York

In Vivo and In Vitro Effects of Cholecystokinin Octapeptide on the Release of Prolactin in Rats

M. Matsumura, A. Yamanoi, S. Yamamoto, H. Mori, S. Saito1
  • Second Department of Internal Medicine, School of Medicine, University of Tokushima, Tokushima, Japan
  • 1First Department of Internal Medicine, School of Medicine, University of Tokushima, Tokushima, Japan
Further Information

Publication History

1983

1984

Publication Date:
14 March 2008 (online)

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Summary

The effect of Cholecystokinin octapeptide (CCK-8) on the release of prolactin (PRL) in rats was studied in vivo and in vitro. Intravenous injection of 5 μg/100g BW of CCK-8 resulted in significant increase in the plasma PRL level after 10 and 20 min. CCK-8 at concentrations of 10-11 M to 10-7 M also caused dose-dependent stimulation of PRL release from dispersed cells of rat anterior pituitary. On the other hand, dopamine inhibited PRL release from dispersed cells of rat anterior pituitary in a dose-related manner at concentrations of 10-8 M to 10-6 M. Release of PRL from the cells was increased by addition of K+ at high concentration (53 mM) in a Ca++-dependent manner. Addition of 10-3 M verapamil to the incubation medium inhibited CCK-8-induced PRL release from the cells. Addition of dopamine (10-7 M) to the incubation medium inhibited PRL release from the cells induced by CCK-8 or high K+ (53 mM).

These results indicate that CCK-8 acts directly on the anterior pituitary cells to stimulate PRL release and that calcium ion is involved in the mechanism of this effect.

Key-Words:

Cholecystokinin Octapeptide - Prolactin - Dopamine - Verapamil - Pituitary Cells