Role of ADP-ribose in 11,12-EET-induced activation of K(Ca) channels in coronary arterial smooth muscle cells. Am J Physiol Heart Circ Physiol 2002 Apr;282(4):H1229-36
Date
03/15/2002Pubmed ID
11893556DOI
10.1152/ajpheart.00736.2001Scopus ID
2-s2.0-0036084912 (requires institutional sign-in at Scopus site) 42 CitationsAbstract
We recently reported that cADP-ribose (cADPR) and ADP-ribose (ADPR) play an important role in the regulation of the Ca(2+)-activated K(+) (K(Ca)) channel activity in coronary arterial smooth muscle cells (CASMCs). The present study determined whether these novel signaling nucleotides participate in 11,12-epoxyeicosatrienoic acid (11,12-EET)-induced activation of the K(Ca) channels in CASMCs. HPLC analysis has shown that 11,12-EET increased the production of ADPR but not the formation of cADPR. The increase in ADPR production was due to activation of NAD glycohydrolase as measured by a conversion rate of NAD into ADPR. The maximal conversion rate of NAD into ADPR in coronary homogenate was increased from 2.5 +/- 0.2 to 3.4 +/- 0.3 nmol*(-1) *mg protein(-1) by 11,12-EET. The regioisomers of 8,9-EET, 11,12-EET, and 14,15-EET also significantly increased ADPR production from NAD. Western blot analysis and immunoprecipitation demonstrated the presence of NAD glycohydrolase, which mediated 11,12-EET-activated production of ADPR. In cell-attached patches, 11,12-EET (100 nM) increases K(Ca) channel activity by 5.6-fold. The NAD glycohydrolase inhibitor cibacron blue 3GA (3GA, 100 microM) significantly attenuated 11,12-EET-induced increase in the K(Ca) channel activity in CASMCs. However, 3GA had no effect on the K(Ca) channels activity in inside-out patches. 11,12-EET produced a concentration-dependent relaxation of precontracted coronary arteries. This 11,12-EET-induced vasodilation was substantially attenuated by 3GA (30 microM) with maximal inhibition of 57%. These results indicate that 11,12-EET stimulates the production of ADPR and that intracellular ADPR is an important signaling molecule mediating 11,12-EET-induced activation of the K(Ca) channels in CASMCs and consequently results in vasodilation of coronary artery.
Author List
Li PL, Zhang DX, Ge ZD, Campbell WBAuthors
William B. Campbell PhD Professor in the Pharmacology and Toxicology department at Medical College of WisconsinDavid X. Zhang MD, PhD Associate Professor in the Medicine department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
8,11,14-Eicosatrienoic AcidAdenosine Diphosphate Ribose
Animals
Arachidonic Acid
Arterioles
Cattle
Coronary Vessels
Hydroxyeicosatetraenoic Acids
In Vitro Techniques
Kinetics
Muscle, Smooth, Vascular
Nitroprusside
Patch-Clamp Techniques
Potassium Channels, Calcium-Activated
Vasodilation
