The pentose cycle and insulin release in isolated mouse pancreatic islets during starvation.

نویسندگان

  • C J Hedeskov
  • K Capito
چکیده

When islets from mice were incubated with 16.7 mM-glucose, previous starvation for 48 h decreased the rate of insulin release by approx. 50% and glucose utilization was decreased by approx. 35%. The maximally extractable activity of glucose 6-phosphate dehydrogenase was diminished by 28% after starvation. The formation of 14CO2 from both [1-14C]glucose was, however, higher than the rate of oxidation of [6-14C]-glucose in islets from both fed and starved mice. The fraction of glucose utilized that was oxidized (specific 14CO2 yield) ranged from one-fifth to one-third and was higher in islets from starved mice with both [1-14C]glucose and [6-14C]glucose as substrate. The contribution of pentose-cycle oxidation to total glucose metabolism was small (3% in the fed state and 4% in the starved state). The absolute rates of glucose carbon metabolism via the pentose-cycle oxidation to total glucose metabolism was small (3% in the fed state and 4% in the starved state). The absolute rates of glucose carbon metabolism via the pentose cycle and the turnover of NADPH in this pathway were identical in islets from fed and starved animals. After incubation at 16.7 mM-glucose for 30 min the contents of glucose (6-phosphate and 6-phosphogluconate were both unchanged by starvation. It is concluded that there is no correlation between the decreased sensitivity of the insulin secretory mechanism during starvation and the metabolism of glucose via the pentose cycle, the islet content of glucose 6-phosphate or 6-phosphogluconate.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Effect of Ganoderma lucidum hydroalcoholic extract on insulin release in rat-isolated pancreatic islets

Objective: Ganoderma Lucidum (G. Lucidum) has been suggested to increase serum insulin level.This study was undertaken to investigateits direct effect on the islets of Langerhans. Material and Methods: Male albino Wistar rats were anesthetized and the islets were isolated after digestion of the pancreas with collagenase. The islets were incubated for 60 min in Krebs bicarbonate buffer containi...

متن کامل

The pentose cycle and insulin release in mouse pancreatic islets.

1. Rates of insulin release, glucose utilization (measured as [(3)H]water formation from [5-(3)H]glucose) and glucose oxidation (measured as (14)CO(2) formation from [1-(14)C]- or [6-(14)C]-glucose) were determined in mouse pancreatic islets incubated in vitro, and were used to estimate the rate of oxidation of glucose by the pentose cycle pathway under various conditions. Rates of oxidation of...

متن کامل

اثر استرس روانی مزمن بر عملکرد گلی‌بن‌کلامید در ترشح انسولین از جزایر لانگرهانس جدا شده موش‌های صحرایی در حضور گلوکز

Background: Regarding the adverse effect of stress on glycemic control in type 2 diabetic patients, the present study investigates the function of Glibenclamide on insulin release from β cells of rat pancreatic islets, subsequent to chronic psychological stress exposure. Methods: In this study 30 male Wistar rats were divided into equal groups of control and experiment (5 groups). Four differ...

متن کامل

Progesterone and Cilostazol Protect mice pancreatic islets from oxidative stress induced by hydrogen peroxide

Abstract Reactive oxygen species and oxidative stress impair β-cell function and reduce insulin secretion. It has been shown that progesterone and cilostazol possess antioxidant properties. The present study was aimed to investigate in vitro pretreatment effect of progesterone and cilostazol on insulin secretion as well as their protective effects against hydrogen peroxide-induced oxidative str...

متن کامل

Progesterone and Cilostazol Protect mice pancreatic islets from oxidative stress induced by hydrogen peroxide

Abstract Reactive oxygen species and oxidative stress impair β-cell function and reduce insulin secretion. It has been shown that progesterone and cilostazol possess antioxidant properties. The present study was aimed to investigate in vitro pretreatment effect of progesterone and cilostazol on insulin secretion as well as their protective effects against hydrogen peroxide-induced oxidative str...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • The Biochemical journal

دوره 152 3  شماره 

صفحات  -

تاریخ انتشار 1975