Journal article
Regulation of hepatic growth hormone receptors in coho salmon ( Oncorhynchus kisutch)
General and comparative endocrinology, Vol.88(2), pp.243-252
1992
Handle:
https://hdl.handle.net/2376/107338
PMID: 1335940
Abstract
Factors potentially regulating hepatic growth hormone (GH) receptors in coho salmon (
Oncorhynchus kisutch) have been investigated. From December to June of the first year, relative changes in hepatic
125I-sGH binding and
35SO
4 incorporation by ceratobranchial cartilage were similar. Stunted salmon, which in seawater have elevated plasma GH yet fail to grow, showed lower hepatic
125I-sGH binding than did normally growing seawater salmon. However, MgCl
2 treatment of stunts' membranes to reveal total specific binding of
125I-sGH indicated receptor occupation by endogenous sGH. Total specific
125I-sGH binding was low in seawater stunts and remained low if these fish remained unfed after return to fresh water, but increased approximately twofold upon feeding. Total specific binding in fasted salmon in fresh water showed a trend toward decreased levels by 1 week; by 3 weeks, binding was 40% lower than in fed fish. There was a positive correlation (
r = 0.600) between condition factor and total specific binding in fed and fasted salmon in fresh water. Two weeks after hypophysectomy total speck binding was 50% lower than in sham-operated control salmon, indicating pituitary regulation of GH receptors. GH treatment reduced both free and total
125I-sGH binding in salmon examined 24 hr after treatment. Treatment with recombinant bovine insulin-like growth factor I, thyroxine, or cortisol did not affect free
125I-sGH binding. Both the pituitary and nutrition appear to be prime regulators of hepatic GH receptors in coho salmon.
Metrics
6 Record Views
Details
- Title
- Regulation of hepatic growth hormone receptors in coho salmon ( Oncorhynchus kisutch)
- Creators
- Elisabeth S GrayKevin M KelleySamuel LawRobert TsaiGraham YoungHoward A Bern
- Publication Details
- General and comparative endocrinology, Vol.88(2), pp.243-252
- Academic Unit
- UNKNOWN
- Publisher
- Elsevier Inc
- Identifiers
- 99900547184801842
- Language
- English
- Resource Type
- Journal article