Journal article
Effects of cortisol and growth hormone replacement on osmoregulation in hypophysectomized coho salmon ( Oncorhynchus kisutch)
General and comparative endocrinology, Vol.67(2), pp.194-201
1987
Handle:
https://hdl.handle.net/2376/106784
PMID: 3040518
Abstract
Both cortisol and GH were able to reverse partially the effects of hypophysectomy on coho salmon (
Oncorhynchus kisutch) as judged by improved seawater (SW) tolerance after long-term treatment; however, neither hormone significantly restored gill Na
+, K
+-ATPase activity. In the first experiment, gill Na
+, K
+-ATPase activity remained low in hypophysectomized (Hx) coho treated with cortisol (15 μg/g body wt, suspended in cocoa butter) for 96 hr (48 hr in fresh water followed by 48 hr in seawater). In addition, plasma sodium levels were higher in the cortisol-treated Hx animals compared with those in untreated controls. In the second experiment, treatment with cortisol-filled Silastic capsules and implants of bovine GH (mixed with cholesterol in a ratio calculated to yield a dose of 1.5 μg/g body wt/week) for 12 days also failed to alter gill Na
+, K
+-ATPase activity, but did reduce plasma sodium levels in animals transferred to SW for 48 hr. These results suggest that these hormones may be involved in the development of hypoosmoregulatory ability in coho salmon. However, the failure of either hormone to restore gill Na
+,K
+-ATPase activity suggests that a combination of these hormones and/or an additional hormone(s) acting in a synchronized fashion may be required for full effectiveness.
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Details
- Title
- Effects of cortisol and growth hormone replacement on osmoregulation in hypophysectomized coho salmon ( Oncorhynchus kisutch)
- Creators
- N.Harold Richman - Department of Zoology, University of California, Berkeley, California 94720 USARichard S Nishioka - Department of Zoology, University of California, Berkeley, California 94720 USAGraham Young - Department of Zoology, University of California, Berkeley, California 94720 USAHoward A Bern - Department of Zoology, University of California, Berkeley, California 94720 USA
- Publication Details
- General and comparative endocrinology, Vol.67(2), pp.194-201
- Academic Unit
- UNKNOWN
- Publisher
- Elsevier Inc
- Identifiers
- 99900546901501842
- Language
- English
- Resource Type
- Journal article