Skeletal muscle sorbitol levels in diabetic rats with and without insulin therapy and endurance exercise training.

Sorbitol accumulation is postulated to play a role in skeletal muscle dysfunction associated with diabetes. The purpose of this study was to determine the effects of insulin and of endurance exercise on skeletal muscle sorbitol levels in streptozotocin-induced diabetic rats. Rats were assigned to one experimental group (control sedentary, control exercise, diabetic sedentary, diabetic exercise, diabetic sedentary no-insulin). Diabetic rats received daily subcutaneous insulin. The exercise-trained rats ran on a treadmill (1 hour, 5X/wk, for 12 weeks). Skeletal muscle sorbitol levels were the highest in the diabetic sedentary no-insulin group. Diabetic sedentary rats receiving insulin had similar sorbitol levels to control sedentary rats. Endurance exercise did not significantly affect sorbitol levels. These results indicate that insulin treatment lowers sorbitol in skeletal muscle; therefore sorbitol accumulation is probably not related to muscle dysfunction in insulin-treated diabetic individuals. Endurance exercise did not influence intramuscular sorbitol values as strongly as insulin.

Immunogenicity of capsular antigens of Pasteurella multocida in turkeys.

Capsular antigens were isolated from Pasteurella multocida, strain P-1059 and their immunogenicity was tested in turkeys. The crude capsular antigen (CCA) was extracted from bacterial cells grown on membranes by heating at 56 C in a 2.5% NaCl solution. The purified polysaccharide antigen (PPA) was obtained by precipitation of CCA by cetylpyridinium chloride. Young adult turkeys were inoculated at 0 and 14 days and were challenge exposed at 28 days by IM inoculation of a live culture of P-1059. The turkeys were observed for 2 weeks and mortality was recorded; bacterial isolation was done at the time of necropsy. In 3 trials, CCA provided 80% to 100% protection; in 1 trial, PPA failed to provide protection. Freund's incomplete adjuvant and aluminum hydroxide gel were effective as potentiating agents when higher than 280 microgram of CCA was used. The CCA showed significant (P less than 0.05) protection after treatment with heat (100 C, 5 min), chloroform, or trypsin, but lost its immunogenicity completely by acid hydrolysis. The CCA was not toxic to mice at 2 mg. The limulus lysate test showed that CCA contained endotoxin in less than or equal to 5% of the total solids. These results indicate that the surface antigen isolated from P multocida by saline extraction was immunogenic in young adult turkeys.