Does acute hyperglycemia alter rat aortic depressor nerve function

Braz journal of Medical Biological Research (2007) 40: 15567-1576 Issn 0100-879x D.A Huber, J. M. do Carmo, J.A. Castania, R. Fazan Jr. and H.C. Salgado It has been shown that diabetes alters baroreflex function. In this present study they wanted to determine what arm of the baroreflex is being altered in response to diabetes. So the recorded the left aortic depressor nerve activity and blood pressure responses. They checked baroreflex activity before and 30minutes after infusion of 0.9% saline, 30% glucose, or 30% mannitol. They assessed baroflex activity in two ways one was by a single bolus of Phenylephrine (8ug/kg) and sodium nitroprusside (16ug/kg) and the other way was by remove and replacing blood in order to change blood pressure by 10mm Hg. What they found was that acute changes of glucose or mannitol in the blood do not lead to changes in the afferent arm of the baroreflex. This finding suggests that the changes that occur in the baroreflex in response to diabetes may be occurring either in the central nervous system or the efferent arm of the baroreflex. -MD