Date of Award
Doctor of Philosophy
An exprimental ketosis was induced in steers by feeding 1,3-butanediol, which is ketogenic, and by injecting phlorizin, which causes glucosuria. In the first trial, four steers received butanediol mixed with the basal ration for 14 days, and phlorizin injected subcutaneously on the last 7 days of butanediol feeding. In the second trial, four steers received butanediol and phlorizin for 28 days with the same basal ration. These steers also were fasted for 9 days. Results are reported as comparisons with the control treatment (basal ration);In the first trial, when steers received butanediol and phlorizin (BDP), plasma glucose decreased by 26%, plasma free fatty acids increased 4-fold, and blood ketone bodies increased nearly 7-fold. BDP also caused glucose irreversible loss, pool size, and space to increase by 64, 24, and 67% and caused glucose total entry rate and recycling to decrease by 26 and 34%. In the second trial, extended treatment with BDP caused changes in blood glucose, ketone bodies, free fatty acids, and glucose irreversible loss similar to those during the first trial. Insulin, glucagon, and growth hormone in plasma, and glycogen and triglyceride in liver were not affected by BDP. Fasting caused a 19% decrease in plasma glucose, hypoinsulinemia, a 6-fold increase in plasma free fatty acids, a 2.6-fold increase in blood ketone bodies, a 51% decrease in glucose irreversible loss, and a 63% decrease in liver glycogen, but fasting did not affect liver triglyceride. BDP caused in vitro hepatic gluconeogenesis from propionate, lactate, alanine, and glycerol to increase by 2.5-, 3.2-, 1.7-, and 2-fold and fasting caused values to increase by 5.2-, 12.4-, 7.5-, and 2.8-fold;Physiological stress imposed by prolonged BDP treatment was no greater than that imposed by short-term BDP treatment. Physiological stress imposed by fasting is greater than that imposed by BDP treatment, as evidenced by higher plasma free fatty acids and lower liver glycogen during fasting. Both BDP and fasting increased in vitro hepatic gluconeogenic capacity. Experimental ketosis in steers receiving BDP is not as severe as lactation ketosis in cows.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Robert Randall Lyle
Lyle, Robert Randall, "Glucose kinetics and hepatic gluconeogenesis in ketotic and fasted steers " (1983). Retrospective Theses and Dissertations. 8418.