title: Histochemical properties of skeletal muscle fibers in streptozotocin-diabetic rats.
abstract: The response of rat gastrocnemius muscle fibers to chronic streptozotocindiabetes was studied. Transverse sections of this muscle from normal and diabetic rats were histochemically assayed for reduced diphosphopyridine nucleotide-diaphorase, myofibrillar adenosine triphosphatase, mitochondrial alpha-glycerophosphate dehydrogenase, beta-hydroxybutyrate dehydrogenase, and alkaline phosphatase activities. Cross-sectional areas of the fiber types were measured, and fiber capillarization and populations estimated. Chemically-induced diabetes appeared to have little effect on the metabolic or morphological properties of slow-twitch fibers. However, a general dedifferentiation occurred in the 2 fast-twitch fiber populations. There was a loss of oxidative potential in the fast-twitch-oxidative-glycolytic fibers, and a significant decrease in size in the fast-twitch-glycolytic fibers. No change in the proportions of slow- and fast-twitch fibers in the muscles of diabetic rats occurred. It is concluded that hypoinsulinism has differential effects on the 3 fiber types in heterogeneous rat skeletal muscle, and that slow-twitch fibers are least affected by the diabetic condition.
mesh_terms: D000251:Adenosine Triphosphatases / Q000032:analysis; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D003920:Diabetes Mellitus / Q000139:chemically induced / Q000201:enzymology* / Q000473:pathology; D008058:Dihydrolipoamide Dehydrogenase / Q000032:analysis; D005993:Glycerolphosphate Dehydrogenase / Q000032:analysis; D006019:Glycolysis; D006651:Histocytochemistry; D006884:Hydroxybutyrate Dehydrogenase / Q000032:analysis; D008297:Male; D008931:Mitochondria, Muscle / Q000201:enzymology; D009132:Muscles / Q000648:ultrastructure; D009210:Myofibrils / Q000201:enzymology*; D051381:Rats; D013311:Streptozocin
chemical_list: D013311:Streptozocin; D005993:Glycerolphosphate Dehydrogenase; D006884:Hydroxybutyrate Dehydrogenase; D008058:Dihydrolipoamide Dehydrogenase; D000469:Alkaline Phosphatase; D000251:Adenosine Triphosphatases