Long-term effects of vanadyl treatment on streptozocin-induced diabetes in rats

• Published in: Diabetes (New York, N.Y.) Vol. 38; no. 11; pp. 1390 - 1395
• Main Authors: PEDERSON, R. A, SASANKA RAMANADHAM, BUCHAN, A. M. J, MCNEILL, J. H
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01-11-1989
• Subjects: Administration, Oral; Animals; Biological and medical sciences; Blood Glucose - metabolism; Bodily secretions; Care and treatment; Diabetes; Diabetes mellitus; Diabetes Mellitus, Experimental - drug therapy; Diabetes Mellitus, Experimental - metabolism; General and cellular metabolism. Vitamins; Glucose - metabolism; Insulin - metabolism; Insulin Secretion; Islands of Langerhans; Islets of Langerhans; Islets of Langerhans - metabolism; Male; Medical sciences; Pharmacology. Drug treatments; Rats; Rats, Inbred Strains; Secretions; Vanadates - administration & dosage; Vanadates - pharmacology; Vanadium; Endocrinopathy; Immunohistochemistry; Vanadyl; Pancreatic hormone; Rat; Diabetes mellitus; Rodentia; Langerhans islet; Glucose tolerance test; Insulin; Long term; Biological activity; Vertebrata; Chemotherapy; Experimental disease; Mammalia; Treatment; Animal
• ISSN: 0012-1797; 1939-327X
• DOI: 10.2337/diab.38.11.1390

The vanadate and vanadyl forms of vanadium have been shown by many investigators to have insulinlike effects on glucose metabolism. Many investigators have shown that vanadium, or its salts, counteracts the hyperglycemia associated with streptozocin-induced diabetes (STZ-D) in the rat, although insulin secretion remains depressed. Studies of the action of vanadate on insulin secretion and glucose metabolism have not addressed the question of possible long-term effects of this compound on glucose metabolism extending beyond the period of oral administration. This study was undertaken to assess the effects of treatment (3 wk) and withdrawal of vanadyl sulfate (13 wk) on glucose metabolism, insulin secretion, and islet insulin content of STZ-D rats. Our results indicate that STZ-D rats that have had blood glucose levels normalized by 3 wk of vanadyl treatment remain normoglycemic after 13 wk of withdrawal from treatment. Normal glucose tolerance was observed in vanadyl-treated diabetic animals despite depressed fasting and glucose-stimulated plasma insulin levels. Insulin secretion from the isolated perfused pancreas was greater after vanadyl treatment than in untreated diabetic rats, although it was only 12% of values from controls. Three weeks of vanadyl treatment of STZ-D rats, followed by 13 wk of withdrawal, yielded islets close in size and insulin content of control islets, even though in vivo and in vitro insulin secretion was impaired. This study has shown that short-term vanadyl treatment of STZ-D rats yields normalization of glucose tolerance and protection of islets from destruction by STZ.