Maintenance of adequate coronary artery blood flow is essential for life. Nitric oxide (NO) may play a critical role in the regulation of flow by opposing vascular smooth muscle (VSM) contraction and restricting the development of coronary artery tone. In fact, enhanced tonic release of NO from coronary endothelium is believed to account, at least in part, for the cardioprotective effect of circulating estrogen in premenopausal women. It is widely believed that the vasodillatory influence of NO is mediated predominantly through the action of cGMP dependent protein kinase (PKG) in smooth muscle cells. However, due primarily to the lack of adequately selective inhibitors, the contribution of PKG to the regulation of vascular tone remains unclear.. New peptide inhibitors of PKG, recently developed in the laboratory of Dr. Wolgang Dostmann at the University of Vermont, may provide the selective tools needed to discern PKG dependence. These peptides are composed of potent, substrate-competitive PKG inhibitor sequences linked to carrier sequences (often referred to as """"""""Trojan horse"""""""" peptides) that facilitate cellular uptake. Recent preliminary studies have revealed that the novel PKG inhibitor peptide, DT-3, effectively permeates cultured vascular smooth muscle cells and selectively inhibits PKG activity. In this project, specific PKG inhibitors including DT-3 will be employed to assess the role of PKG action will subsequently be addressed, primarily focusing on PKG dependent activation of Ca2+ sensitive potassium channels (K/Ca). The findings of this study will provide valuable insights into the fundamental mechanisms that determine cardiac blood flow.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
1F32HL010502-01
Application #
6298954
Study Section
Pharmacology A Study Section (PHRA)
Program Officer
Schucker, Beth
Project Start
2001-03-01
Project End
Budget Start
2001-03-01
Budget End
2002-02-28
Support Year
1
Fiscal Year
2001
Total Cost
$34,832
Indirect Cost
Name
University of Vermont & St Agric College
Department
Pharmacology
Type
Schools of Medicine
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405