Back
Acta Physiologica 2009; Volume 196, Supplement 671
Scandinavian Physiological Society’s Annual Meeting
8/14/2009-8/16/2009
Uppsala, Sweden
INSULIN AND GLUCAGON ARE RELEASED AS ANTISYNCHRONOUS PULSES FROM HUMAN ISLETS.
Abstract number: P11
HELLMAN1 B, SALEHI1 A, GYLFE1 E, GRAPENGIESSER1 E
1Department of Medical Cell Biology, Uppsala University, Biomedicum Box 571, SE-75123 Uppsala, Sweden. [email protected]
Previous studies of the perfused rat pancreas have indicated that pulses of insulin release are antisynchronous to those of glucagon (Grapengiesser et al. 2006). Species differences in the cytoarchitecture of the islets make it important to explore the temporal relationship between the insulin and glucagon pulses in humans. Batches of 10 -15 islets isolated from normoglycemic human cadaveric donors were perifused at a rate of 0.6 ml/min. The effluent was collected in 30 sec fractions and the islet hormones were measured in duplicate with radioimmunoassay. Increase of glucose from 3 to 20 mM resulted in repetitive 78 min pulses of insulin, glucagon and somatostatin. It is likely that perifusion of batches of islets lacking neural connections result in overestimation of the pulse duration. Measurements of insulin release from single islets with a similar technique indicate pulse periods of 4 min. There was no amplification of average hormone release with time, and the shapes of the pulses were maintained during an observation period of 80 min. Analyses of temporal relationships revealed that pulses of insulin and somatostatin coincide but are antisynchronous to those of glucagon.The antisynchrony resulted in more than 20-fold variations of the insulin/glucagon ratio during a pulse cycle. The antisynchrony between insulin and glucagon should be essential for minute-to-minute regulation of hepatic glucose production. Reference: Grapengiesser, E., Salehi, A., Qader, S.S. & Hellman, B. 2006. Endocrinology 147, 34723477
To cite this abstract, please use the following information:
Acta Physiologica 2009; Volume 196, Supplement 671 :P11