TY - JOUR
T1 - Growth hormone and insulin-like growth factor-1 differentially stimulate the expression of preprosomatostatin mRNAs in the Brockmann bodies of rainbow trout, Oncorhynchus mykiss
AU - Melroe, Gregory T.
AU - Ehrman, Melissa M.
AU - Kittilson, Jeffrey D.
AU - Sheridan, Mark A.
N1 - Funding Information:
We would like to thank Leslie Alexander, Darlene Knutson, Craig Moore, Lindsey Norbeck, Bart Slagter, and Nicole Very for their assistance with these experiments and the preparation of the manuscript. We also are grateful to Professor Hiroshi Kawauchi (Kitasato University) for the generous donation of sGH and to the National Institutes of Health (USA) for providing oGH and anti-oGH anti-serum. This research was supported by grants from the US National Science Foundation (IBN 00764616) and the US Department of Agriculture (98-35206-6410) to M.A.S.
PY - 2004/5/1
Y1 - 2004/5/1
N2 - We previously characterized three cDNAs obtained from the endocrine pancreas (Brockmann body) of rainbow trout that encode for distinct preprosomatostatin (PPSS) molecules: PPSS I containing somatostain-14 (SS-14) at its C-terminus and two separate PPSS IIs, PPSS II′ and PPSS II″, containing [Tyr7,Gly10]-SS-14 at their C-termini. In this study, we examined the control of PPSS I, PPSS II ′, and PPSS II″ mRNA expression by growth hormone (GH) and insulin-like growth factor-1 (IGF-1). Rainbow trout implanted with GH for 21 days displayed elevated pancreatic expression of all PPSS mRNAs compared to control animals. Growth hormone directly stimulated the expression of all pancreatic PPSS mRNAs in vitro in a dose-dependent manner; however, GH was a more potent stimulator of PPSS II′ expression than of PPSS I or PPSS II″ expression. Insulin-like growth factor-1 also directly stimulated the expression of PPSS mRNAs in a dose-dependent manner in Brockmann bodies incubated in vitro; IGF-1 was a more potent stimulator of PPSS I and PPSS II′ expression than of PPSS II″ expression. These results indicate that the expression of PPSS mRNAs in the Brockmann body of trout is differentially regulated by GH and IGF-1 and suggest that SS mediate the feedback regulation of GH and IGF-1.
AB - We previously characterized three cDNAs obtained from the endocrine pancreas (Brockmann body) of rainbow trout that encode for distinct preprosomatostatin (PPSS) molecules: PPSS I containing somatostain-14 (SS-14) at its C-terminus and two separate PPSS IIs, PPSS II′ and PPSS II″, containing [Tyr7,Gly10]-SS-14 at their C-termini. In this study, we examined the control of PPSS I, PPSS II ′, and PPSS II″ mRNA expression by growth hormone (GH) and insulin-like growth factor-1 (IGF-1). Rainbow trout implanted with GH for 21 days displayed elevated pancreatic expression of all PPSS mRNAs compared to control animals. Growth hormone directly stimulated the expression of all pancreatic PPSS mRNAs in vitro in a dose-dependent manner; however, GH was a more potent stimulator of PPSS II′ expression than of PPSS I or PPSS II″ expression. Insulin-like growth factor-1 also directly stimulated the expression of PPSS mRNAs in a dose-dependent manner in Brockmann bodies incubated in vitro; IGF-1 was a more potent stimulator of PPSS I and PPSS II′ expression than of PPSS II″ expression. These results indicate that the expression of PPSS mRNAs in the Brockmann body of trout is differentially regulated by GH and IGF-1 and suggest that SS mediate the feedback regulation of GH and IGF-1.
KW - Growth hormone
KW - Insulin-like growth factor 1
KW - Preprosomatostatin expression
KW - Rainbow trout
UR - http://www.scopus.com/inward/record.url?scp=1842736447&partnerID=8YFLogxK
U2 - 10.1016/j.ygcen.2004.01.011
DO - 10.1016/j.ygcen.2004.01.011
M3 - Article
C2 - 15081835
AN - SCOPUS:1842736447
SN - 0016-6480
VL - 136
SP - 353
EP - 359
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 3
ER -