Influence Of Prenatal Stress On Insulin Response To A Glucose Challenge In Yearling Brahman Bulls.

We hypothesized that stressing cows during gestation (prenatal stress, PNS) would increase the insulin sensitivity of their progeny. Specifically, 12 prenatally stressed (dams transported for 2h on d 60, 80, 100, 120, and 140 of gestation) and 12 Control (dams not transported) yearling bulls of similar BW (298.50 ± 5.95 kg) and balanced for temperament (4 temperamental and 8 calm per group) were subjected to an iv glucose tolerance test to compare insulin responsiveness and glucose clearance. Following 12 h off feed the bulls were fitted with jugular vein catheters and placed in individual stanchions. After a 2h acclimation period, bulls were administered a glucose tolerance test (0.5 mL/kg BW of 50% dextrose solution). Blood samples were collected at 10min intervals for 40 min and then at 20min intervals until 180 min postchallenge. Serum concentrations of glucose and insulin were determined by enzymatic assay and ELISA, respectively. Data were analyzed using mixed models procedures of SAS with repeated measures. Basal concentrations of insulin (P< 0.53) and glucose (P< 0.35) were not affected by PNS. Serum insulin increased in both CON and PNS bulls within 10 min of glucose administration with a tendency for PNS bulls to reach the insulin peak earlier (P= 0.09) and return to basal insulin earlier (P< 0.01) than CON bulls (Table 066). Glucose concentration wasn't affected by treatment (P= 0.14) or by the interaction of treatment by time (P= 0.53). Time to reach basal glucose concentration was unaffected by treatment (P= 0.73). The area under the response curve was greater for glucose (P< 0.01) and lower for insulin (P< 0.01) in the PNS bulls compared to CON bulls. The insulin to glucose ratio was lower (P<0.06) in PNS bulls.These results support our hypothesis that PNS increased sensitivity to insulin. Glucose and insulin response variables to a glucose challenge in PNS and Control bulls. Glucose and insulin response variables to a glucose challenge in PNS and Control bulls.