Portal and peripheral vein insulin responses to intravenous glucose in the rhesus monkey
Rayfield, E.J.; Faulkner, R.T.; Czajkowski, W.
Journal of Laboratory and Clinical Medicine 87(6): 919-924
1976
ISSN/ISBN: 0022-2143 PMID: 819601 Document Number: 100136
Catheterization of the portal vein and bilateral femoral veins were performed under general anesthesia in 6 healthy male rhesus monkeys. Four days later, sequential, simultaneous peripheral and portal plasma samples were obtained for glucose and immunoreactive insulin determinations before and after administration of 0.5 Gm. of glucose per kilogram (over a 1-minute period) via the opposite peripheral catheter. Two phases of insulin secretion were noted in both portal and peripheral plasma samples. An immediate early-phase insulin response was noted with a peak response at 1 minute followed by a rapid decline to a nadir at 5 minutes. A second phase of insulin secretion was evident with a peak response at 10 minutes and a subsequent decline to basal levels by 60 minutes. Simultaneous portal vein and peripheral vein glucose concentrations were not significantly different from each other by paired analysis. Thus, in the rhesus monkey peripheral insulin concentrations following intravenous glucose exhibit a biphasic response closely paralleling pancreatic insulin secretion.