Age-induced changes in pancreatic islet blood flow: evidence for an impaired regulation in diabetic GK rats.
The present study aimed to compare longitudinal variations in islet blood perfusion in rats with different degrees of impairment of glucose metabolism. For this purpose, mildly diabetic Goto-Kakizaki (GK) rats, glucose intolerant F(1) hybrids of GK and Wistar (W) rats (H), and control W rats were examined at 5 wk, 12 wk, or 1 yr of age, using the microsphere technique for blood flow measurements. W rats showed progressively increasing islet blood flow (IBF) throughout the experiment. Both GK and H rats demonstrated increasing IBF between 5 and 12 wk. However, H rats showed no further increment in IBF at 1 yr, whereas GK rats displayed a pronounced decrease in IBF between 12 wk and 1 yr of age. The augmented IBF seen in older W rats may constitute an adaptation to the increasing demand for insulin secretion in aging rats. The inability to adapt to the increased demand for insulin secretion by upregulation of islet blood flow could contribute to the progressive deterioration of glucose metabolism seen in the aging GK rat.
Svensson
A M
AM
Department of Medical Cell Biology, Uppsala University, SE-751 23 Uppsala, Sweden.
Ostenson
C G
CG
Jansson
L
L
D000375:Aging; D000818:Animals; D001783:Blood Flow Velocity; D001786:Blood Glucose / Q000378:metabolism; D003920:Diabetes Mellitus / Q000503:physiopathology*; D005260:Female; D018149:Glucose Intolerance / Q000503:physiopathology; D005951:Glucose Tolerance Test; D007515:Islets of Langerhans / Q000098:blood supply*; D007700:Kinetics; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose