EFFECTS OF KETONES, ACETATE, AND GLUCOSE ON INVITRO IMMUNOGLOBULIN SECRETION BY BOVINE LYMPHOCYTES

Individual and combined effects of ketones, acetate, and glucose on Ig M secretion by bovine blood lymphocytes were evaluated in vitro. Super natants from 14-d cultures of unstimulated and mitogen- or antigen-sti mulated mono-nuclear leukocytes were harvested and analyzed for total and antigen-specific IgM. Ketones, acetate, and 1,3-butanediol individ ually added up to 6.25 mM had no effect on total IgM secreted by cells grown in medium containing 11.1 mM glucose. However, butyrate at 6.25 mM inhibited IgM secretion. Addition of a mixture of ketones approxim ating plasma levels of severely ketotic cows inhibited mitogen-induced IgM secretion in 11.1 mM glucose-supplemented cultures. Results from experiments evaluating effects of glucose concentrations on IgM secret ion indicated that plasma glucose concentration associated with the ke totic state (1.66 mM), compared with normal plasma glucose concentrati on (3.33 mM), did not affect total or antigen-specific IgM secretion. Supplementation of cultures containing up to 3.33 mM glucose with keto nes, acetate, or both either had no effect or a modest stimulatory eff ect. These data indicate that effects of ketones and acetate on IgM se cretion are dependent on the concentration of glucose in culture and s uggest that changes in plasma glucose, ketone, and acetate concentrati ons associated with bovine ketosis do not alter IgM secretion in vivo.