Urinary chiro-inositol and myo-inositol excretion is elevated in the diabetic db/db mouse and streptozotocin diabetic rat.
Inositol phosphoglycan molecules containing either D-chiro-inositol or myo-inositol have been isolated from various mammalian tissues and are putative mediators of insulin action. Urinary excretion of inositols appears to be altered in diabetes mellitus; however, the relationships with different types of diabetes are unclear. The objective of this study was to determine the urinary excretion of chiro- and myo-inositol in diabetic animal models, including streptozotocin (STZ) rats, db/db mice, and fa/fa Zucker rats. In STZ rats (type 1 diabetes), 12-hr urinary excretion of chiro-inositol was elevated 336-fold and myo-inositol excretion was elevated 47-fold compared with their nondiabetic counterparts. When corrected for creatinine, chiro-inositol excretion was 259-fold higher and myo-inositol excretion was 36-fold higher in STZ rats than in normal rats. The same pattern was observed in db/db mice (type 2 diabetes), where 12-hr urinary chiro-inositol excretion was elevated 247-fold compared with normal mice. When corrected for creatinine, chiro-inositol excretion was 2455-fold higher and urinary myo-inositol excretion was elevated 8.5-fold in db/db mice compared with normal mice. The fa/fa Zucker rats (impaired glucose tolerance) had a pattern of urinary inositol excretion that was similar to the nondiabetic animals (lean Zucker rats, C57BL/6 mice, and Sprague-Dawley rats). In summary, urinary chiro-inositol and myo-inositol excretion was elevated in animal models of type 1 and type 2 diabetes mellitus, concomitant with hyperglycemia and glucosuria.
Kawa
Julianne M
JM
Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.
Przybylski
Roman
R
Taylor
Carla G
CG
D000818:Animals; D001786:Blood Glucose; D002849:Chromatography, Gas; D003404:Creatinine / Q000652:urine; D003921:Diabetes Mellitus, Experimental / Q000652:urine*; D005260:Female; D007294:Inositol / Q000652:urine*; D007328:Insulin / Q000097:blood; D008297:Male; D051379:Mice; D051381:Rats
D001786:Blood Glucose; D007328:Insulin; D007294:Inositol; D003404:Creatinine