Influence of bile duct occlusion on plasma insulin responses to glucose in rats

The plasma insulin and glucose responses to intravenous glucose administration were studied in rats after 1, 3, and 6 weeks of bile duct occlusion. One week after the occlusion the first-phase plasma insulin response to glucose was clearly reduced, whereas the late-phase response was increased. Despite a relative hypoglycemia, a clearly increased glucose-induced elevation of plasma insulin was noted after 3 weeks' bile flow obstruction, at which time the median 15-min plasma insulin response to glucose was 38 microU/ml in duct-occluded rats and 7 microU/ml in control rats (p less than 0.001). At the same time an increased glucose elimination rate of 3.59%/min in duct-occluded rats and 3.08%/min in control rats (median values; p less than 0.05) was observed. Available evidence suggests that the effect on the insulin response may be induced by the trypsin-sensitive branch of the 'enteroinsular axis'.