Effect of vitamin C on sorbitol in the lens of guinea-pigs made diabetic with streptozotocin

• Published in: British journal of nutrition Vol. 67; no. 3; pp. 445 - 456
• Main Authors: Bates, C. J., Cowen, T. D., Evans, P. H.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01-05-1992
• Subjects: adenosine triphosphate; Adenosine Triphosphate - metabolism; adrenal glands; Animals; aqueous humor; Aqueous Humor - metabolism; ascorbic acid; Ascorbic Acid - administration & dosage; Ascorbic Acid Deficiency - metabolism; Biological and medical sciences; blood glucose; Blood Glucose - metabolism; blood plasma; Body Weight; creatinine; diabetes; Diabetes Mellitus, Experimental - metabolism; Diet; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; eye lens; eyes; glucose; Glycosuria - metabolism; growth; Guinea Pigs; Guinea-pig lens; Lens, Crystalline - metabolism; liver; Liver - metabolism; Male; Medical sciences; Metabolic Effects of Vitamin C; nutrient intake; nutritional status; peptidases; Sorbitol; Sorbitol - metabolism; Streptozocin; Streptozotocin diabetes; thiols; Time Factors; urine; Vitamin C; vitamin deficiencies; Sorbitol; Streptozotocin diabetes; Guinea-pig lens; Vitamin C; Endocrinopathy; Cataract; Ascorbic acid; Diabetes mellitus; Rodentia; Vitamin; Vitamin deficiency; Vertebrata; Experimental disease; Mammalia; Guinea pig; Animal; Lens; Malnutrition; Streptozotocin; Nutritional status
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1079/BJN19920049

Marginally vitamin C-deficient guinea-pigs treated with the diabetogenic agent streptozotocin were compared with those liberally supplied with vitamin C, for functional indices of vitamin C status, particularly in the eye lens. Weanling male Dunkin–Hartley guinea-pigs were fed on diets with 0.1 g vitamin C/kg (marginally deficient), or 5 g/kg (liberally supplied), and some received intraperitoneal streptozotocin (two doses of 150 mg/kg body-weight). About half the streptozotocin-treated animals had high urinary glucose following an oral glucose dose; these animals also grew more slowly than the others. At 4 months after streptozotocin the animals were killed for measurement of tissue vitamin C, glucose and sorbitol. Streptozotocin moderately increased the concentration of glucose in plasma, lens and aqueous humour. Lens sorbitol levels increased only in the group exposed to streptozotocin plus marginal vitamin C. There was a significant (P < 0.02) positive correlation between urinary glucose and lens sorbitol levels overall. Liberal vitamin C intake may thus counteract the effect of streptozotocin diabetes on lens sorbitol, suggesting a new function of vitamin C, possibly related to cataractogenesis and to the biochemical lesions associated with diabetes.