Mammalian voltage-gated Na+ channels are encoded by a multigene family. The relationship of cardiac Na+ channel(s) to this family is currently unknown. """"""""TTX- resistant"""""""" cardiac NA+ channels in other excitable tissue. Current evidence suggests that cardiac Na+ channel(s) most likely encoded by undiscovered genes within this multigene family. The broad long-term objectives of these studies are: 1) To determine to what extent the specialized functional properties of the cardiac Na+ channel(s) are accounted for by distinct gene sequences or by other modifications of known Na+ channel genes. 2) To characterize the distinct molecular structures of the cardiac Na+ channel(s) which account for these specialized functional properties. 3) To further elucidate properties of other members of the multigene family by comparison with the cardiac Na+ channel(s). 4) To determine mechanisms controlling cardiac Na+ channel expression, including these involved in differential expression of multiple Na+ channel isoforms in their respective tissues.
The specific aims and experimental design to achieve these goals are: 1) To generate plasmid or bacteriophage cDNA libraries from P6 rat heart, and to screen these libraries with cRNA probes from the rat brain Na channel 11 sequence. 2) To analysis; 3) To determine the developmental, regional and tissue specific expression and functional properties of cardiac Na+ channel mRNAs. 4) To construct full-length cDNAs and to express them in heterologous systems including Xenopus oocytes and transfected mammalian cells, to determine which specialized functional properties of cardiac Na channels are encoded by the distinct sequence of the cardiac Na+ channel alpha-subunit. The health-related significance of this work is that the molecular basis of normal and abnormal cardiac impulse conduction will be elucidated, and a molecular basis for the design of more specific anti- arrhythmic agents determined.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL037217-03
Application #
3352752
Study Section
Physiology Study Section (PHY)
Project Start
1989-04-01
Project End
1994-03-31
Budget Start
1991-04-01
Budget End
1992-03-31
Support Year
3
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of Chicago
Department
Type
Schools of Medicine
DUNS #
225410919
City
Chicago
State
IL
Country
United States
Zip Code
60637
Wang, S Y; Feelisch, M; Harrison, D G et al. (1996) Preferential dilation of large coronary microvessels by the mononitrates SPM-4744 and SPM-5185. J Cardiovasc Pharmacol 27:587-93
Baumgarten, C M; Dudley Jr, S C; Rogart, R B et al. (1995) Unitary conductance of Na+ channel isoforms in cardiac and NB2a neuroblastoma cells. Am J Physiol 269:C1356-63
Harrison, D G; Ohara, Y (1995) Physiologic consequences of increased vascular oxidant stresses in hypercholesterolemia and atherosclerosis: implications for impaired vasomotion. Am J Cardiol 75:75B-81B
Wheatley, R M; Dockery, S P; Kurz, M A et al. (1994) Interactions of nitroglycerin and sulfhydryl-donating compounds in coronary microvessels. Am J Physiol 266:H291-7
Kurz, M A; Boyer, T D; Whalen, R et al. (1993) Nitroglycerin metabolism in vascular tissue: role of glutathione S-transferases and relationship between NO. and NO2- formation. Biochem J 292 ( Pt 2):545-50
Harrison, D G; Bates, J N (1993) The nitrovasodilators. New ideas about old drugs. Circulation 87:1461-7
Satin, J; Kyle, J W; Chen, M et al. (1992) A mutant of TTX-resistant cardiac sodium channels with TTX-sensitive properties. Science 256:1202-5
Satin, J; Kyle, J W; Chen, M et al. (1992) The cloned cardiac Na channel alpha-subunit expressed in Xenopus oocytes show gating and blocking properties of native channels. J Membr Biol 130:11-22
Harrison, D G (1991) Endothelial modulation of vascular tone: relevance to coronary angioplasty and restenosis. J Am Coll Cardiol 17:71B-76B
Cribbs, L L; Satin, J; Fozzard, H A et al. (1990) Functional expression of the rat heart I Na+ channel isoform. Demonstration of properties characteristic of native cardiac Na+ channels. FEBS Lett 275:195-200

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