This paper is only available as a PDF. To read, Please Download here.
Defects in the deposition of glycogen and the regulation of glycogen synthesis in the livers of severely insulin-deficient rats can be reversed, in vivo, within hours of insulin administration. Using primary cultures of hepatocytes isolated from normal and diabetic rats in a serum-free chemically defined medium, the present study addresses the chronic action of insulin to facilitate the direct effects of insulin and glucose on the short term regulation of the enzymes controlling glycogen metabolism. Primary cultures were maintained in the presence of insulin, triiodothyronine, and cortisol for 1-3 days. On day 1 in alloxan diabetic cultures, 10(-7) M insulin did not acutely activate glycogen synthase over a period of 15 min or 1 h, whereas insulin acutely activated synthase in cultures of normal hepatocytes. By day 3 in hepatocytes isolated from alloxan diabetic rats, insulin effected an approximate 30% increase in per cent synthase I within 15 min as was also the case for normal cells. The acute effect of insulin on synthase activation was independent of changes in phosphorylase alpha. Whereas glycogen synthase phosphatase activity could not be shown to be acutely affected by insulin, the total activity in diabetic cells was restored to normal control values over the 3-day culture period. The acute effect of 30 mM glucose to activate glycogen synthase in cultured hepatocytes from normal rats after 1 day of culture was missing in hepatocytes isolated from either alloxan or spontaneously diabetic (BB/W) rats. After 3 days in culture, glucose produced a 50% increase in glycogen synthase activity during a 10-min period under the same conditions. These studies clearly demonstrate that insulin acts in a chronic manner in concert with thyroid hormones and steroids to facilitate acute regulation of hepatic glycogen synthesis by both insulin and glucose.
REFERENCES
- J. Am. Chem. Soc. 1957; 79: 6340-6346
- Biochem. Biophys. Res. Commun. 1970; 39: 774-782
- Proc. Natl. Acad. Sci. U. S. A. 1970; 65: 383-387
- Am. J. Physiol. 1971; 220: 724-734
- J. Biol. Chem. 1973; 248: 3483-3488
- J. Biol. Chem. 1972; 247: 3229-3235
- Biochem. Biophys. Res. Commun. 1973; 53: 937-943
- FEBS Lett. 1973; 30: 25-28
- Biochem. Biophys. Res. Commun. 1974; 61: 222-229
- Biochem. Biophys. Res. Commun. 1976; 69: 997-1003
- Biochemistry. 1978; 17: 406-410
- Biochem. J. 1979; 182: 727-734
- J. Biol. Chem. 1980; 255: 4028-4034
- Horm. Metab. Res. 1981; 13: 376-378
- FEBS Lett. 1981; 129: 123-126
- Biochim. Biophys. Acta. 1981; 675: 17-23
- Life Sci. 1983; 32: 467-474
- Biochem. J. 1983; 210: 783-787
- J. Biol. Chem. 1984; 259: 12470-12474
- Biochem. J. 1984; 217: 427-434
- Czech M.P. Molecular Basis of Insulin Action. Plenum Press, New York1985: 247-261
- Biochem. Biophys. Res. Commun. 1973; 53: 466-474
- Biochem. J. 1975; 150: 153-165
- Am. J. Physiol. 1978; 234: E13-E19
- Biochim. Biophys. Acta. 1979; 583: 36-46
- Am. J. Physiol. 1981; 240: E539-E543
- Biochem. Biophys. Res. Commun. 1979; 87: 177-183
- Biochemistry. 1963; 2: 669-675
- Biochim. Biophys. Acta. 1971; 242: 69-80
- J. Biol. Chem. 1973; 248: 4552-4560
- Anal. Biochem. 1968; 25: 486-499
- Eur. J. Biochem. 1975; 54: 341-350
- Anal. Biochem. 1972; 47: 20-27
- Methods Enzymol. 1968; 12: 163-169
- J. Biochem. (Tokyo). 1984; 95: 1691-1696
- Life Sci. 1978; 23: 1083-1092
- J. Biol. Chem. 1961; 236: 299-304
- Proc. Natl. Acad. Sci. U. S. A. 1967; 58: 1515-1519
- J. Biol. Chem. 1970; 245: 903-906
- Czech M.P. Molecular Basis of Insulin Action. Plenum Press, New York1985: 213-233
- Eur. J. Biochem. 1983; 130: 227-234
- Eur. J. Biochem. 1971; 18: 582-587
- J. Biol. Chem. 1981; 256: 2851-2855
- J. Biochem. (Tokyo). 1982; 92: 699-708
- In Vitro (Rockville). 1984; 20: 923-931
- J. Biol. Chem. 1985; 260: 1521-1526
- Can. J. Biochem. Cell Biol. 1985; 63: 333-340
Article info
Publication history
Published online: January 15, 1986
Identification
Copyright
© 1986 ASBMB. Currently published by Elsevier Inc; originally published by American Society for Biochemistry and Molecular Biology.
User license
Creative Commons Attribution (CC BY 4.0) | How you can reuse
Elsevier's open access license policy

Creative Commons Attribution (CC BY 4.0)
Permitted
- Read, print & download
- Redistribute or republish the final article
- Text & data mine
- Translate the article
- Reuse portions or extracts from the article in other works
- Sell or re-use for commercial purposes
Elsevier's open access license policy