Effects of Taurine on Myocardial cGMP/cAMP Ratio, Antioxidant Ability, and Ultrastructure in Cardiac Hypertrophy Rats Induced by Isoproterenol - Advances in Experimental Medicine and Biology - page 203

the present study demonstrated that taurine could inhibit the injury induced by ISO
by increasing myocardial negative inotropic effect and antioxidant ability, decreas-
ing the hypertrophic response to isoproterenol and protecting the integrity of
myocardial ultrastructure, decreasing myocardial leak of CK-MB.

Abbreviations

ISO Isoprenaline

CK-MB Creatine kinase heart isoenzyme

cAMP Cyclic adenosine monophosphate

cGMP Cyclic guanosine monophosphate

MDA Malondialdehyde

SOD Superoxide dismutase

GSH Reduced glutathione

GSH-Px Glutathione peroxidase

T-AOC Total antioxidation capacity

21.1 Introduction

Taurine(2-aminoethanessulphonic acid), a sulfur-containing amino acid, is the most
abundant free amino acid in the human body and accounts for more than 50% of the
total amino acid pool in the mammalian heart (Lombardini 1996 ) . Although it can
be synthesized endogenously, the major source of taurine is from the diet. Earlier
studies demonstrated that nutritional depletion of taurine leads to the development
of a dilated cardiomyopathy in cat and fox (Pion et al. 1987 ; Moise et al. 1991 ) .
Accumulating clinical and experimental studies has shown that taurine deficiency is
associated with structural and functional disorders in heart (Yamori et al. 2001 ;
Shiny et al. 2005 ; Ito et al. 2008 ); exogenous administration of taurine possesses a
preventive and therapeutic effect on a variety of cardiovascular diseases (Shiny et al.
2005 ; Allard et al. 2006 ; YJ et al. 2008 ; Li et al. 2009 ; Sahin et al. 2011 ) .
Cardiac hypertrophy is an adaptive response of the heart muscle to a variety of
extrinsic and intrinsic stimuli; it represents a typical feature of various cardiomyo-
pathies including ischemic heart disease and hypertension. Cardiac hypertrophy is
initially compensatory for an increased workload; however, prolongation of this
process eventually leads to heart failure (Lorell and Carabello 2000 ; Tardiff 2006 ;
Hill and Olson 2008 ). It has been reported that taurine reduced angiotensin II (Ang
II)-induced cardiac hypertrophy by inhibiting the activation of protein kinase C and
mitogen-associated protein kinase (Azuma et al. 2000 ) . Li et al. ( 2009 ) have shown
taurine prevents cardiomyocyte apoptosis by inhibiting NADPH oxidase-mediated
calpain activation in norepinephrine (NE)-induced cardiomyocytes (Li et al. 2009 ) .
Although studies in animal and humans suggest that taurine plays an important