The enhanced hyperglycemic response to hemorrhage hypotension in obese rats is related to an impaired baroreflex.

Abstract

We assessed the hyperglycemic response to hemorrhage in rats fed with hypercaloric diet. Male wistar rats (4 weeks) were fed a chow (CD, n=6) or hypercaloric diet (HD, n=7) for 19 weeks. After 19 weeks, the animals were submitted to implantation of silastic cannula into jugular vein for drugs administration, blood collecting and hemorrhage (1.2 mL/100g body wt/2 min). A polyethylene catheter was inserted into abdominal aorta for cardiovascular monitoring. An utonomic balance was evaluated by testing baroreflex sensitivity (with phenylephrine and sodium nitroprusside). Our data showed that hypercaloric diet induced obesity. We observed a reduction in baroreflex sensitivity (50%) and an increase in hemorrhagic hyperglycemia response (35%) in HD compared to CD group (p<0.01). We found a negative correlation between the change in baroreflex sensitivity and the increase in hyperglycemic response to hemorrhage (r=0.72, p<0.01) and in the Lee index (r=0.72, p<0.01). A positive correlation between the increased Lee index and hemorrhage hyperglycemia (r=0.90, p<0.01) was also observed. Our data showed that obesity induced by hypercaloric diet promotes an autonomic imbalance characterized by enhanced hemorrhagic hyperglycemia response, which is related to impaired baroreflex sensitivity. Supported by: CNPq and FAPEMIG.