Insulin responsiveness of diaphragm tissue and adipose cellularity in XXXX selected for rapid growth.

@entity28 @entity19 @entity1735 @entity1717 @entity1602 @entity413 @entity897
Four lines of @entity19 , two lines selected for rapid growth (large body weights) (M16 and H6) and their unselected control lines (ICR and C2, respectively), were examined for traits related to @entity28 . The M16 line is @entity28 while the other three lines are normal in body composition at 10 weeks of age when fed stock diet. In experiment I, @entity19 were fed stock diet and examined at intervals from 4 to 22 weeks of age. @entity19 were fed either a high- @entity1735 or high-fat diet in experiment II and examined at 4, 6 and 10 weeks of age. The traits measured were serum @entity413 , serum insulin and in vitro insulin responsiveness of diaphragm muscle. Epididymal adipose cellularity was determined at 10 weeks of age. Insulin responsiveness was determined for the diaphragm muscle by @entity897 uptake. Body weights differed significantly (M16 greater than H6 greater than ICR greater than C2, P less than 0.01). The M16 @entity28 line was @entity1602 and mildly @entity1717 while the H6 line was hypoglycemic and normoinsulinemic. Basal @entity897 uptakes by diaphragm muscle were similar among lines while the insulin-stimulated uptake by M16 and H6 lines was less (P less than 0.01) than the stimulated uptake by their control lines. Diet did not affect basal uptakes, but high-fat diets reduced (P less than 0.01) the insulin stimulated uptakes when compared to the high- @entity1735 diet. Selected lines had more and larger epididymal adipocytes than control lines when fed the stock diet (P less than 0.01). Decreased insulin responsiveness of muscle tissue among the lines occurred concomitantly with an increase in adipocyte size.
