AJP - Gastrointestinal and Liver Physiology, Vol 245, Issue 5 628-G634, Copyright © 1983 by American Physiological Society
Manganese action on pancreatic protein synthesis in normal and diabetic rats
M. Korc
The effects of manganese on [3H]phenylalanine incorporation into protein
were studied in pancreatic acini prepared from normal and
streptozotocin-induced diabetic rats. In the absence of added Ca2+
manganese exerted a biphasic effect on [3H]phenylalanine incorporation in
both groups of acini. Significant stimulation occurred at 3 X 10(-5) M
manganese. At higher concentrations manganese inhibited incorporation. The
magnitude of stimulation was similar in all acini, whereas the magnitude of
inhibition was greater in acini from normal rats. Addition of Ca2+ to
incubation media abolished the stimulatory effect of manganese in normal
rat acini and greatly enhanced it in diabetic rat acini, significant
stimulation now occurring at 10(-5) M manganese. The magnitude of
inhibition was again greater in acini from normal rats. Insulin in vivo
partially reversed the diabetes-induced alterations in acinar cell
responsiveness to manganese. The present findings suggest that
streptozotocin-induced diabetes is associated with postreceptor alterations
in the pancreatic acinar cells.
