Site-specific localization of protein kinase C isoforms in rat pancreas.
BACKGROUND
Protein kinase C (PKC), a major signal-transducing enzyme, is recognized to play an important role in the regulation of pancreatic exocrine and endocrine secretion, and yet the distribution of PKC isoforms in rat pancreas has remained unclarified.


OBJECTIVE
We examined the precise localization of PKC isoforms to elucidate the role of PKC in the normal rat pancreas.


METHODS
Male Sprague-Dawley rats were used throughout the experiment. For Western blot analysis, the islet of Langerhans and the acinar tissue were separated by the collagenase digestion method. Also, the whole pancreas was taken out and immunohistochemistry performed.


RESULTS
According to Western blot analysis, PKC-alpha, -gamma, -delta, -epsilon, -zeta, and -lambda were detected in both acinar and islet cells while PKC-beta II were observed exclusively in the islet. PKC-beta I was not observed. On immunohistochemistry, the immunoreactivities of PKC isoforms were observed as follows: PKC-alpha, weakly in some endocrine cells and ductal epithelium; PKC-beta II, mainly in the islet center; PKC-gamma, in the islet, intrapancreatic ganglia and ductal epithelium; PKC-delta, in the islet periphery, weakly in some acinar cells and ductal epithelium; PKC-epsilon, strongly in the islet, acinar cell and ductal epithelium; PKC-zeta, in the islet, acinar cell and ductal epithelium; PKC-lambda in some endocrine cells and ductal epithelium.


CONCLUSIONS
These results suggest that the intrapancreatic site-specific existence of PKC isoforms may regulate pancreatic exocrine and endocrine functions via a PKC-mediated signal transduction.
Department of Physiology, College of Medicine, Catholic University of Korea, 505 Banpo-dong, Socho-gu, Seoul 137-701, Korea.
M J
MJ
Kim
Y S
YS
Lee
K H
KH
Lee
D S
DS
Min
S H
SH
Yoon
S J
SJ
Hahn
M S
MS
Kim
Y H
YH
Jo
D000818:Animals; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000166:cytology / Q000201:enzymology*; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D010179:Pancreas / Q000166:cytology / Q000201:enzymology*; D011493:Protein Kinase C / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley
D007527:Isoenzymes; D011493:Protein Kinase C