Abstract
In the present study, we have measured protein kinase C (PKC) specific activities and total diacylglycerol (DAG) level in the aorta and heart of rats, which showed that after 2 weeks of streptozotocin (STZ)-induced diabetes, membranous PKC specific activity and total DAG content were increased significantly by 88% and 40% in the aorta and by 21% and 72% in the heart, respectively. Hyperglycemia was identified as being a causal factor since elevated glucose levels increased DAG levels in cultured aortic endothelial and smooth muscle cells. Analysis by immunoblotting revealed that only α and βII PKC isoenzymes are detected in these two tissues and vascular cells among those studied. In STZ-induced diabetic rats, βII isoenzyme is preferentially increased in both aorta and heart, whereas PKC α did not change significantly. The increases in membranous PKC specific activity and DAG level are observed in both spontaneous diabetes-prone diabetic BB rats as well as in STZ-induced diabetic BB and Sprague-Dawley rats, which persisted for up to 5 weeks. After 2 weeks of diabetes without treatment, the normalization of blood glucose levels for up to 3 weeks with islet cell transplants in STZ-induced diabetic BB rats reversed the biochemical changes only in the heart, but not in the aorta. These results suggest that PKC activity and DAG level may be persistently activated in the macrovascular tissues from diabetic animals and indicate a possible role for these biochemical parameters in the development of diabetic chronic vascular complications.
| Original language | English |
|---|---|
| Pages (from-to) | 11059-11063 |
| Number of pages | 5 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 89 |
| Issue number | 22 |
| DOIs | |
| Publication status | Published - Nov 26 1992 |
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Preferential elevation of protein kinase C isoform βII and diacylglycerol levels in the aorta and heart of diabetic rats : Differential reversibility to glycemic control by islet cell transplantation. / Inoguchi, T.; Battan, R.; Handler, E.; Sportsman, J. R.; Heath, W.; King, G. L.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 89, No. 22, 26.11.1992, p. 11059-11063.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Preferential elevation of protein kinase C isoform βII and diacylglycerol levels in the aorta and heart of diabetic rats
T2 - Differential reversibility to glycemic control by islet cell transplantation
AU - Inoguchi, T.
AU - Battan, R.
AU - Handler, E.
AU - Sportsman, J. R.
AU - Heath, W.
AU - King, G. L.
PY - 1992/11/26
Y1 - 1992/11/26
N2 - In the present study, we have measured protein kinase C (PKC) specific activities and total diacylglycerol (DAG) level in the aorta and heart of rats, which showed that after 2 weeks of streptozotocin (STZ)-induced diabetes, membranous PKC specific activity and total DAG content were increased significantly by 88% and 40% in the aorta and by 21% and 72% in the heart, respectively. Hyperglycemia was identified as being a causal factor since elevated glucose levels increased DAG levels in cultured aortic endothelial and smooth muscle cells. Analysis by immunoblotting revealed that only α and βII PKC isoenzymes are detected in these two tissues and vascular cells among those studied. In STZ-induced diabetic rats, βII isoenzyme is preferentially increased in both aorta and heart, whereas PKC α did not change significantly. The increases in membranous PKC specific activity and DAG level are observed in both spontaneous diabetes-prone diabetic BB rats as well as in STZ-induced diabetic BB and Sprague-Dawley rats, which persisted for up to 5 weeks. After 2 weeks of diabetes without treatment, the normalization of blood glucose levels for up to 3 weeks with islet cell transplants in STZ-induced diabetic BB rats reversed the biochemical changes only in the heart, but not in the aorta. These results suggest that PKC activity and DAG level may be persistently activated in the macrovascular tissues from diabetic animals and indicate a possible role for these biochemical parameters in the development of diabetic chronic vascular complications.
AB - In the present study, we have measured protein kinase C (PKC) specific activities and total diacylglycerol (DAG) level in the aorta and heart of rats, which showed that after 2 weeks of streptozotocin (STZ)-induced diabetes, membranous PKC specific activity and total DAG content were increased significantly by 88% and 40% in the aorta and by 21% and 72% in the heart, respectively. Hyperglycemia was identified as being a causal factor since elevated glucose levels increased DAG levels in cultured aortic endothelial and smooth muscle cells. Analysis by immunoblotting revealed that only α and βII PKC isoenzymes are detected in these two tissues and vascular cells among those studied. In STZ-induced diabetic rats, βII isoenzyme is preferentially increased in both aorta and heart, whereas PKC α did not change significantly. The increases in membranous PKC specific activity and DAG level are observed in both spontaneous diabetes-prone diabetic BB rats as well as in STZ-induced diabetic BB and Sprague-Dawley rats, which persisted for up to 5 weeks. After 2 weeks of diabetes without treatment, the normalization of blood glucose levels for up to 3 weeks with islet cell transplants in STZ-induced diabetic BB rats reversed the biochemical changes only in the heart, but not in the aorta. These results suggest that PKC activity and DAG level may be persistently activated in the macrovascular tissues from diabetic animals and indicate a possible role for these biochemical parameters in the development of diabetic chronic vascular complications.
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U2 - 10.1073/pnas.89.22.11059
DO - 10.1073/pnas.89.22.11059
M3 - Article
C2 - 1438315
AN - SCOPUS:0026489335
VL - 89
SP - 11059
EP - 11063
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 22
ER -