While a functional cytochrome P450-dependent mixed function oxidase system has been identified in the kidney, the distribution of isozymes along the tubule epithelium and their relative contribution to arachidonic acid metabolism has not been completely characterized. Products of P450-dependent arachidonic acid metabolism mediate natriuretic responses in the proximal tubule in response to angiotensin II (AII). The purpose of this proposal is to establish the identity of the isozymes responsible for arachidonic acid concentration and activity, focusing on the proximal convoluted tubule. The metabolic profile of each isozyme in arachidonic acid metabolism will be determined and compared with the profile from intact cells. The effect of induction of specific isozymes by treatment of rabbits with established inducers such as phenobarbital, B-naphthoflavone, and clofibrate on arachidonic acid metabolism in response to AII will be determined to try and establish the identity of the hydroxylase. These experiments will be complimented by inhibitors of different isozymes which may be present in proximal cells. If the arachidonic acid hydroxylase appears to be a unique P450 as a result of inhibitor and induction experiments, it will be isolated and characterized from kidney cortex microsomes. This will be accomplished by a combination of chromatofocusing and ion exchange HPLC, monitoring the fractions for hydroxylase activity. Having established the identity of the arachidonic acid hydroxylase, experiments will be run to determine those factors which regulate the expression of the enzyme by coupling in situ hybridization histochemical studies with treatments which alter AII and/or the P450 concentrations. Experiments will also be done to determine whether the hydroxylase is expressed and is inducible in tissue culture.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL041618-02
Application #
3880637
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Case Western Reserve University
Department
Type
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
Huang, Chunfa; Miller, Richard Tyler (2010) Novel Ca receptor signaling pathways for control of renal ion transport. Curr Opin Nephrol Hypertens 19:106-12
Yu, Changqing; Yang, Zhiwei; Ren, Hongmei et al. (2009) D3 dopamine receptor regulation of ETB receptors in renal proximal tubule cells from WKY and SHRs. Am J Hypertens 22:877-83
Zeng, Chunyu; Asico, Laureano D; Yu, Changqing et al. (2008) Renal D3 dopamine receptor stimulation induces natriuresis by endothelin B receptor interactions. Kidney Int 74:750-9
Zeng, Chunyu; Armando, Ines; Luo, Yingjin et al. (2008) Dysregulation of dopamine-dependent mechanisms as a determinant of hypertension: studies in dopamine receptor knockout mice. Am J Physiol Heart Circ Physiol 294:H551-69
Zeng, Chunyu; Villar, Van Anthony M; Eisner, Gilbert M et al. (2008) G protein-coupled receptor kinase 4: role in blood pressure regulation. Hypertension 51:1449-55
Resnick, Andrew; Hopfer, Ulrich (2008) Mechanical stimulation of primary cilia. Front Biosci 13:1665-80
Woost, Philip G; Kolb, Robert J; Chang, Chung-Ho et al. (2007) Development of an AT2-deficient proximal tubule cell line for transport studies. In Vitro Cell Dev Biol Anim 43:352-60
Resnick, Andrew; Hopfer, Ulrich (2007) Force-response considerations in ciliary mechanosensation. Biophys J 93:1380-90
Huang, Chunfa; Miller, R Tyler (2007) Regulation of renal ion transport by the calcium-sensing receptor: an update. Curr Opin Nephrol Hypertens 16:437-43
Ulmasov, Barbara; Bruno, Jonathan; Woost, Philip G et al. (2007) Tissue and subcellular distribution of CLIC1. BMC Cell Biol 8:8

Showing the most recent 10 out of 110 publications