Intracellular calcium as a regulator of the mitochondrial ATP synthase in cultured cardiomyocytes

1990 ◽  
Vol 18 (4) ◽  
pp. 554-555 ◽  
Author(s):  
ANIBH M. DAS ◽  
DAVID A. HARRIS
Keyword(s):  
Intracellular Calcium ◽  
Atp Synthase ◽  
Mitochondrial Atp Synthase ◽  
Cultured Cardiomyocytes

Defects in regulation of mitochondrial ATP synthase in cardiomyocytes from spontaneously hypertensive rats

1990 ◽  
Vol 259 (4) ◽  
pp. H1264-H1269 ◽  
Author(s):  
A. M. Das ◽  
D. A. Harris
Keyword(s):  
Atp Synthase ◽  
Energy Demand ◽  
Ruthenium Red ◽  
Shr Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Mitochondrial Atp Synthase ◽  
Positive Inotropic Agents ◽  
Wistar Kyoto ◽  
Cultured Cardiomyocytes

Control of mitochondrial ATP synthase capacity was investigated in cultured cardiomyocytes from normotensive (Wistar-Kyoto) and spontaneously hypertensive (SHR) rats. The basal ATP synthase capacity in quiescent cardiomyocytes was raised in the hypertensive rats (2.9 +/- 0.1 mumol.min-1.mg protein-1) compared with normotensive rats (2.2 +/- 0.1 mumol.min-1.mg-1). However, this high value is restored to normal after treatment of the cells with verapamil or ruthenium red; agents that do not affect ATP synthase capacity in normal cells. It is concluded that abnormally high intramitochondrial Ca2+ levels, or an abnormal mitochondrial response to Ca2+ concentration, are responsible for ATP synthase activation in quiescent SHR cells. Cardiomyocytes from normotensive rats respond to increased energy demand (caused by electrical stimulation or treatment with positive inotropic agents) by increasing their ATP synthase capacity up to twofold. Cells from SHR rats are unable to control their ATP synthase in this way. It is concluded that some defect in regulation of the mitochondrial ATP synthase occurs in myocytes from hypertensive rats.

scholarly journals Regulation of the mitochondrial ATP synthase in intact rat cardiomyocytes

1990 ◽  
Vol 266 (2) ◽  
pp. 355-361 ◽  
Author(s):  
A M Das ◽  
D A Harris
Keyword(s):  
Atp Synthase ◽  
Inhibitor Protein ◽  
Detectable Change ◽  
Rat Cardiomyocytes ◽  
Naturally Occurring ◽  
Regulator Protein ◽  
Mitochondrial Atp Synthase ◽  
Rat Heart Myocytes ◽  
Cultured Cardiomyocytes

The ATP synthase capacity of rat heart myocytes can be measured in sonicated cell suspensions and in sonicated preparations of cultured cardiomyocytes. This procedure allows the rapid measurement of mitochondrial function in response to changes in the metabolic status of the cell. In cultured myocytes, transitions in ATP synthase capacity (with no detectable change in cellular ATP concentration) accompany a change to anoxia or electrically stimulated contraction (rise of 70%). These changes are reversed on returning to the original conditions. Exposure of myocytes to low pH has little effect on basal ATP synthase capacity (down to values less than pH 6), but markedly affects cellular ATP levels and the response of the cells to anoxia and reoxygenation, possibly mimicking changes seen in ischaemic heart. Similar effects are seen in suspensions of freshly prepared myocytes, but these preparations are less stable and more pH-sensitive than are cells in culture. It is proposed that mitochondria in vivo are directly regulated at the level of the ATP synthase, and that a regulator protein, the naturally occurring inhibitor protein from mitochondria, may be responsible for this regulation.

scholarly journals The ATP Synthase Deficiency in Human Diseases

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 325
Author(s):  
Chiara Galber ◽  
Stefania Carissimi ◽  
Alessandra Baracca ◽  
Valentina Giorgio
Keyword(s):  
Oxidative Phosphorylation ◽  
Atp Synthase ◽  
Mitochondrial Protein ◽  
High Energy ◽  
Neurocognitive Disorders ◽  
Human Diseases ◽  
Age Related ◽  
Muscle Tissues ◽  
Mitochondrial Atp Synthase ◽  
Genes Encoding

Human diseases range from gene-associated to gene-non-associated disorders, including age-related diseases, neurodegenerative, neuromuscular, cardiovascular, diabetic diseases, neurocognitive disorders and cancer. Mitochondria participate to the cascades of pathogenic events leading to the onset and progression of these diseases independently of their association to mutations of genes encoding mitochondrial protein. Under physiological conditions, the mitochondrial ATP synthase provides the most energy of the cell via the oxidative phosphorylation. Alterations of oxidative phosphorylation mainly affect the tissues characterized by a high-energy metabolism, such as nervous, cardiac and skeletal muscle tissues. In this review, we focus on human diseases caused by altered expressions of ATP synthase genes of both mitochondrial and nuclear origin. Moreover, we describe the contribution of ATP synthase to the pathophysiological mechanisms of other human diseases such as cardiovascular, neurodegenerative diseases or neurocognitive disorders.

scholarly journals Lysine methylation of mitochondrial ATP synthase subunit c stored in tissues of dogs with hereditary ceroid lipofuscinosis

1994 ◽  
Vol 269 (13) ◽  
pp. 9906-9911
Author(s):  
M.L. Katz ◽  
J.S. Christianson ◽  
N.E. Norbury ◽  
C.L. Gao ◽  
A.N. Siakotos ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Lysine Methylation ◽  
Subunit C ◽  
Ceroid Lipofuscinosis ◽  
Mitochondrial Atp Synthase
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