Feeding and metabolic patterns in rats with truncular vagotomy or with transplanted beta-cells

The night- and daytime basal plasma insulin levels and insulin responses to an intravenous glucose load, basal blood glucose levels and rates of glucose uptake, and, finally, the diurnal patterns of blood glucose levels were investigated in normal compared to vagotomized Wistar rats. The same comparisons were made between normal and diabetic Lewis rats recovered after fetal pancreas transplantation in the kidney capsule. In an attempt to clarify the relationship between the metabolic and feeding diurnal patterns, a detailed study of the meal pattern of vagotomized and transplanted rats was performed. It was shown that 1) a truncular vagotomy abolished both the metabolic and feeding diurnal cyclicity; 2) both the metabolic and feeding diurnal rhythms were maintained in case of a selective denervation beta-cells. The relationship between the metabolic and feeding diurnal rhythms and the role of the vagus nerve are discussed.