Increased expression of Galphaq protein in the heart of streptozotocin-induced diabetic rats.
- Author:
Jung Mee YANG
1
;
Chin Ho CHO
;
Kyoung Ae KONG
;
Ik Soon JANG
;
Hae Won KIM
;
Yong Sung JUHNN
Author Information
1. Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Korea.
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
G proteins;
protein kinase;
cAMP dependent protein kinase;
protein kinase C
- MeSH:
Animal;
Ca(2+)-Calmodulin Dependent Protein Kinase/metabolism;
Cyclic AMP-Dependent Protein Kinases/metabolism;
Diabetes Mellitus, Experimental/metabolism*;
Diabetes Mellitus, Experimental/drug therapy;
Diabetes Mellitus, Experimental/chemically induced;
GTP-Binding Proteins/metabolism*;
Insulin/pharmacology;
Liver/metabolism;
Liver/drug effects;
Male;
Myocardium/metabolism*;
Protein Kinase C/metabolism;
Rats;
Rats, Sprague-Dawley;
Signal Transduction;
Streptozocin
- From:Experimental & Molecular Medicine
1999;31(4):179-184
- CountryRepublic of Korea
- Language:English
-
Abstract:
Heart disease is one of the major cause of death in diabetic patients, but the thogenesis of diabetic cardio-myopathy remains unclear. In this experiment, to sess the significance of G protein signaling pathways in the pathogenesis of abetic cardiomyopathy, we analyzed the expression of G proteins and the tivities of second messenger dependent protein kinases: cAMP-dependent protein nase (PKA), DAG-mediated protein kinase C (PKC), and calmodulin dependent otein kinase II (CaM kinase II) in the streptozotocin induced diabetic rat art. The expression of Galphaq was increased by slightly over 10% (P<0.05) in abetic rat heart, while Galphas, Galphai, and Gbeta remained unchanged. The A activity in the heart did not change significantly but increased by 27%<0.01) in the liver. Insulin treatment did not restore the increased activity the liver. Total PKC activity in the heart was increased by 56% (P<0.01), and sulin treatment did not restore such increase. The CaM kinase II activity in e heart remained at the same level but was slightly increased in the liver 4% increase, P<0.05). These findings of increased expression of Galphaq in the reptozotocin-diabetic rat heart that are reflected by the increased level of C activity and insensitivity to insulin demonstrate that alteration of Galphaq y underlie, at least partly, the cardiac dysfunction that is associated with abetes. Copyright 2000 Academic Press.
