Effect of aging on B-cell function and replication in rat pancreas after 90% pancreatectomy.
We studied the effect of aging on B-cell function and replication in depancreatized rats. Male Wistar rats, at the ages of 1, 5, and 15 months, underwent 90% pancreatectomy (Px) or a sham operation, and islet function and regeneration were examined 3 weeks later. Plasma glucose levels in 1-month-old rats reached a peak 2 weeks after Px and then declined, while those in 5- and 15-month-old rats reached significant levels as early as the day after Px or 2 days after surgery and continued to increase over the following 3 weeks. Consequently, in contrast to young Px rats, weight loss due to severe diabetes was observed in 5- and 15-month-old Px rats. Plasma glucose responses to intravenous glucose loading (0.5 g/kg body weight) were much greater in older Px rats than in younger rats. There was a marginal insulin response to glucose in 1-month-old Px rats, whereas no insulin response to glucose was observed in older Px animals. The insulin content of the residual pancreas was increased threefold in 1-month-old Px rats, but there was no increase in 5- and 15-month-old Px rats. These data demonstrate that the effect of reducing islet mass is much greater in aged rats than in young rats and that the replicatory capacity of B cells tends to diminish after adulthood has been reached.
Tanigawa
K
K
Department of Clinical Nutrition, Suzuka University of Medical Science and Technology, Japan.
Nakamura
S
S
Kawaguchi
M
M
Xu
G
G
Kin
S
S
Tamura
K
K
D000375:Aging / Q000502:physiology*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000502:physiology; D005951:Glucose Tolerance Test; D007328:Insulin / Q000032:analysis / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000502:physiology*; D008297:Male; D009929:Organ Size / Q000502:physiology; D010179:Pancreas / Q000503:physiopathology* / Q000601:surgery; D010180:Pancreatectomy; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D007328:Insulin