Title

Temperature-Induced Phase Shift of Daily Rhythm of Serum Prolactin in Gulf Killifish

Document Type

Article

Publication Date

1978

Publication Title

Nature

ISSN

0028-0836

Volume

271

Issue/No.

5644

First Page

469

Last Page

470

Abstract

Daily variations in circulating levels of the pituitary hormone prolactin have been reported in several vertebrates, including fishes. In some animals, the 24-h rhythm changes seasonally with respect to the time of day that maximum and minimum prolactin levels occur. It has been hypothesised that this seasonal change in phase of prolactin rhythm is an important component of the mechanism controlling seasonality in vertebrates. Because water temperature is generally considered the principal environmental regulator of seasonal changes in reproduction and metabolism in many fishes, including the gulf killifish Fundulus grandis, we determined the daily rhythm of serum prolactin concentrations in fish held at temperatures that are stimulatory (20 °C) or inhibitory (28 °C) for reproductive development. We found that an increase in water temperature from 20° to 28 °C phase shifts the daily variation of serum prolactin with respect to the daily photoperiod in F. grandis.

Comments

©1978 Nature Publishing Group

DOI

10.1038/271469a0

Peer Reviewed

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