Abstract

This is a study of the myocardial sarcolemma and the extracellular matrix. This project attempts to gain an understanding of the function of the myocardial sarcolemma from an ultrastructural analysis of the components of the cell surface (glycocalyx) in the bilayer, their relationship to each other, to the extracellular matrix and to membrane transport. The approach is to study the macromolecular architecture of the bilayer and glycocalyx/extracellular matrix with state-of-the-are freeze-fracture and immunoelectron microscopy. The overall aims are to determine (1) if any of the intramembrane particles as revealed in freeze-fracture and freeze-etch membrane are related to ion transport and (2) which specific macromolecules within the glycocalyx have an important structural and functional relationship to the bilayer and to components of he extracellular matrix. The methodology is to (1) examine the filament of the glycocalyx and extracellular matrix to determine in untreated tissue their configuration and identity. This will be performed in normal hearts, during development and after brief periods of ischemia, (2) to determine the distribution and localization in the bilayer of two major transport proteins, i.e. Na,K- ATPase and Na-Ca exchanger. A combination of the following techniques will be used on isolated adult myocytes, cultured myocytes and heart tissue: ultra-rapid freezing, freeze-drying, freeze-substitution, low temperature embedding, freeze-fracture and etch, antibody and immunogold labeling and label fracture. The proposed research has a two-fold significance, (1) by identifying structural components of the glycocalyx/extracellular matrix and intramembrane particles int he bilayer, with specific membrane function it addresses a question fundamental to the biology of all cells and (2) it utilizes stat-of-the-art ultrastructure to focus on structure-function relationships (both physiological and pathological) of the sarcolemma and extracellular matrix, where in the heart there is little information.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL028791-13
Application #
2216359
Study Section
Cardiovascular and Renal Study Section (CVB)
Project Start
1982-05-01
Project End
1996-04-30
Budget Start
1994-05-01
Budget End
1996-04-30
Support Year
13
Fiscal Year
1994
Total Cost
Indirect Cost

  Institution

Name
University of California Los Angeles
Department
Physiology
Type
Schools of Medicine
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095

  Publications

Chen, F; Mottino, G; Shin, V Y et al. (1997) Subcellular distribution of ankyrin in developing rabbit heart--relationship to the Na+-Ca2+ exchanger. J Mol Cell Cardiol 29:2621-9
McDonough, A A; Zhang, Y; Shin, V et al. (1996) Subcellular distribution of sodium pump isoform subunits in mammalian cardiac myocytes. Am J Physiol 270:C1221-7
Liu, Q; Yan, H; Dawes, N J et al. (1996) Insulin-like growth factor II induces DNA synthesis in fetal ventricular myocytes in vitro. Circ Res 79:716-26
Chen, F; Mottino, G; Klitzner, T S et al. (1995) Distribution of the Na+/Ca2+ exchange protein in developing rabbit myocytes. Am J Physiol 268:C1126-32
Frank, J S; Mottino, G; Chen, F et al. (1994) Subcellular distribution of dystrophin in isolated adult and neonatal cardiac myocytes. Am J Physiol 267:C1707-16
Li, Z P; Burke, E P; Frank, J S et al. (1993) The cardiac Na+-Ca2+ exchanger binds to the cytoskeletal protein ankyrin. J Biol Chem 268:11489-91
Li, Z; Smith, C D; Smolley, J R et al. (1992) Expression of the cardiac Na(+)-Ca2+ exchanger in insect cells using a baculovirus vector. J Biol Chem 267:7828-33
Frank, J S; Mottino, G; Reid, D et al. (1992) Distribution of the Na(+)-Ca2+ exchange protein in mammalian cardiac myocytes: an immunofluorescence and immunocolloidal gold-labeling study. J Cell Biol 117:337-45
Frank, J S; Fogelman, A M (1989) Ultrastructure of the intima in WHHL and cholesterol-fed rabbit aortas prepared by ultra-rapid freezing and freeze-etching. J Lipid Res 30:967-78
Frank, J S; Beydler, S; Wheeler, N et al. (1988) Myocardial sarcolemma in ischemia: a quantitative freeze-fracture study. Am J Physiol 255:H467-75

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