Articles in PresS. Am J Physiol Renal Physiol (April 20, 2004). 10.1152/ajprenal.00383.2003
1
Luminal Flow Induces eNOS Activation and Translocation in the Rat Thick Ascending Limb II: Role of PI3 Kinase and Hsp90
Pablo A. Ortiz*, Nancy J. Hong, and Jeffrey L. Garvin
*Corresponding Author:
Pablo A. Ortiz, Ph.D.
Division of Hypertension and Vascular Research Department of Internal Medicine Henry Ford Hospital 2799 W. Grand Boulevard Detroit, MI 48202 Phone: (313) 916-8501 Fax: (313) 916-1479 Email:
[email protected] Running tittle:
PI3 kinase-dependent eNOS translocation in the THAL
Copyright © 2004 by the American Physiological Society.
2 Abstract We have identified endothelial nitric oxide synthase (eNOS) as the NOS isoform that regulates NaCl absorption by the thick ascending limb of the loop of Henle (THAL). Recently, we found that augmenting luminal flow induces eNOS activation and translocation to the apical membrane of THALs (companion study, Ortiz PA, Hong NJ, and Garvin J.L.). However, it is not known how flow regulates eNOS activity and translocation in these cells. In endothelial cells eNOS activation by shear stress, endothelial growth factor and estradiol is mediated by the phosphatidylinositol 3-OH kinase (PI3 kinase) pathway. We hypothesized that increasing luminal flow induces eNOS activation and translocation via activation of the PI3 kinase cascade. Pretreatment of THALs with wortmannin, a PI3 kinase inhibitor, reduced flow- induced NO release by 75% (from 53.6 ± 6 to 13.2 ± 5.7 pA/mm of tubule, n = 7; p
