Hormone-sensitive lipase, role

R. Roduit, P. Masiello, S.P. Wang, H. Li, G.A. Mitchell, and M. Prentki, A role for hormone-sensitive lipase in glucose-stimulated insulin secretion a study in hormone-sensitive lipase deficient mice. Diabetes, 2001, 50, 1970-1975. 

Yeaman SJ (2004) Hormone-sensitive lipase—new roles for an old enzyme. Biochem J 379(Pt 1) 11-22... 

Figure 6. The roles and regulation of lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) in adipose tissue. GLUT 4, glucose transporter.

Severson, D. L., Khoo, J. C., and Steinberg, D., 1977, Role of phosphoprotein phosphatases in reversible deactivation of chicken adipose tissue hormone-sensitive lipase, /. Biol. Chem. 252 1484. 

Cardiomyocytes are known to express HSL [68, 78, 79 see below] and the hormone-responsiveness of myocardial lipolysis suggests that HSL is probably responsible. In addition, the heart can synthesize and secrete apoB-containing lipoproteins [3]. If, as apparently with the liver, endogenous TAG is mobilized for lipoprotein assembly via a lipolytic event the question arises can HSL fulfil this function in the heart or is another lipase involved in a mechanism identical to that in the liver It has been proposed that mobilization of endogenous cardiac TAG for lipoprotein secretion provides the heart with a safety valve to dispose of excess lipid [3] and thus protects against lipotoxicity [65]. Lipoapoptosis observed in the heart leads to the development of heart failure [80, 81]. If, as apparently with skeletal muscle [82], excess TAG accumulation plays a role in insuhn resistance, hpoprotein secretion may enable cardiac muscle insuhn sensitivity in the face of an excessive flux of FA. 

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