Impaired insulin release in aging rats: metabolic and ionic events.
We investigated the effect of aging on glucose uptake, glucose-induced O2 consumption, glucose-induced 45Ca movements, and calmodulin content to elucidate age-related impairment of glucose-induced insulin release in pancreatic islets of Wistar rats. Intact pancreatic islets from old (24-month-old) rats showed impaired glucose-induced insulin release; glucose uptake and O2 consumption were lower in old than in young (2-month-old) or adult (12-month-old) rats. Moreover, 45Ca uptake and calmodulin content were decreased in pancreatic islets from older rats, which explained the impairment in glucose-induced insulin release in aging. No major differences between the 3 age groups in glucose-induced 45Ca efflux in pancreatic islets were observed.
Castro
M
M
Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Granada, Spain.
Pedrosa
D
D
Osuna
J I
JI
D000375:Aging / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002132:Calcium Radioisotopes; D002147:Calmodulin / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
D002132:Calcium Radioisotopes; D002147:Calmodulin; D007328:Insulin; D005947:Glucose; D002118:Calcium