A possible role for growth hormone (GH) in stimulating islet B-cell replication was examined in neonatal rat pancreatic monolayer cultures. Addition of ovine GH (1000 ng/ml) to serum-free medium for 2 days resulted in a significant increase (+114%) in [3H]thymidine labeling of B-cells in aldehyde-thionine-stained autoradiographs, and a similar increase in the B-cell mitotic index. The stimulatory effects of GH on islet B-cell replication were greatest in serum-free medium, unaffected by glucose concentrations (2.8–16.7 mM), and not accompanied by any stimulation of insulin release. The threshold concentration of GH for a significant stimulatory effect on B-cell replication was 30 ng/ml. The insulin-like growth factor, multiplication stimulating activity (MSA), also effectively stimulated B-cell replication. Although some effects of GH are mediated by the insulin-like growth factors (IGFs), the effects of GH on B-cell replication did not appear to be mediated by IGFs since (1) the maximal effect of GH (+156%) was significantly > that of MSA (+91%); (2) the combination of maximal stimulatory concentrations of GH and MSA produced an additive effect; and (3) a significant effect of GH on B-cell replication was observed as early (8 h) as that produced by MSA. These results suggest that GH can stimulate islet B-cell replication directly, and that this effect may not depend on production of either insulin-like growth factors.
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April 01 1983
Growth Hormone Stimulates Islet B-Cell Replication in Neonatal Rat Pancreatic Monolayer Cultures
Alexander Rabinovitch;
Alexander Rabinovitch
Division of Endocrinology and Metabolism, Department of Medicine, University of Miami School of Medicine
Miami, Florida
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Carol Quigley;
Carol Quigley
Division of Endocrinology and Metabolism, Department of Medicine, University of Miami School of Medicine
Miami, Florida
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Matthew M Rechler
Matthew M Rechler
Section on Biochemistry of Cell Regulation, Laboratory of Biochemical Pharmacology, National Institute of Arthritis, Diabetes, and Digestive and Kidney Disease
Bethesda, Maryland
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Address reprint requests to Dr. Alexander Rabinovitch, Department of Medicine (R-134), University of Miami School of Medicine, P.O. Box 016960, Miami, Florida 33101.
Diabetes 1983;32(4):307–312
Article history
Received:
July 01 1982
Revision Received:
November 08 1982
PubMed:
6339303
Citation
Alexander Rabinovitch, Carol Quigley, Matthew M Rechler; Growth Hormone Stimulates Islet B-Cell Replication in Neonatal Rat Pancreatic Monolayer Cultures. Diabetes 1 April 1983; 32 (4): 307–312. https://doi.org/10.2337/diab.32.4.307
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