Journal article
The effects of recombinant bovine somatotropin (rbST) on tissue IGF-I, IGF-I receptor, and GH mRNA levels in rainbow trout, Oncorhynchus mykiss
General and comparative endocrinology, Vol.135(3), pp.324-333
2004
Handle:
https://hdl.handle.net/2376/116951
PMID: 14723884
Abstract
Numerous studies demonstrated that rbST increased growth rates in several fish species, and several species exhibit GH production in tissues other than the pituitary. The role of tissue GH and IGF-I in regulating fish growth is poorly understood. Therefore an experiment was conducted to examine the effects of rbST treatment on tissue GH, IGF-I, and IGF-I receptor-A (rA) expression in rainbow trout. Rainbow trout (550
±
10
g) received either intra-peritoneal injections of rbST (120
μg/g body weight) or vehicle on days 0 and 21, and tissue samples were collected on days 0, 0.5, 1, 3, 7, and 28 (
n=6/day/trt). Total RNA was isolated and assayed for steady-state levels of IGF-I, IGF-IrA, and GH mRNA using quantitative RT-PCR. Insulin-like growth factor-I mRNA levels increased in liver, gill, gonad, muscle, brain, and intestine in response to rbST treatment (
P<0.10). Liver IGF-I mRNA increased (
P<0.01) 0.5 day after treatment and remained elevated throughout the trial. Intestine IGF-I mRNA increased (
P<0.05) in treated fish from day 1 to day 3, then decreased to day 7 and increased again at day 28, and remained elevated above control levels throughout the trial. Gill IGF-I mRNA levels increased (
P<0.05) 1 day after treatment and remained elevated throughout the trial. Heart IGF-IrA mRNA levels decreased (
P<0.05) while gonad GH mRNA levels increased (
P<0.10) following rbST treatment. These results demonstrate that rbST treatment increased IGF-I mRNA levels in extra-hepatic tissues, and decreased heart IGF-IrA and increased gonad GH mRNA levels. Because the primary source for endocrine IGF-I is liver, the increased IGF-I mRNA reported in extra-hepatic tissues may indicate local paracrine/autocrine actions for IGF-I for local physiological functions.
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Details
- Title
- The effects of recombinant bovine somatotropin (rbST) on tissue IGF-I, IGF-I receptor, and GH mRNA levels in rainbow trout, Oncorhynchus mykiss
- Creators
- Peggy R Biga - Department of Animal and Veterinary Science, Center for Reproductive Biology, University of Idaho, Moscow, ID 83844, USAGerald T Schelling - Department of Animal and Veterinary Science, Center for Reproductive Biology, University of Idaho, Moscow, ID 83844, USARonald W Hardy - Department of Animal and Veterinary Science, Center for Reproductive Biology, University of Idaho, Moscow, ID 83844, USAKenneth D Cain - Department of Fisheries and Wildlife, Center for Reproductive Biology, University of Idaho, Moscow, ID 83844, USAKenneth Overturf - Hagerman Fish Culture Experiment Station, University of Idaho, Hagerman, ID 83332, USATroy L Ott - Department of Animal and Veterinary Science, Center for Reproductive Biology, University of Idaho, Moscow, ID 83844, USA
- Publication Details
- General and comparative endocrinology, Vol.135(3), pp.324-333
- Academic Unit
- Center for Reproductive Biology
- Publisher
- Elsevier Inc
- Identifiers
- 99900547593201842
- Language
- English
- Resource Type
- Journal article