Please use this identifier to cite or link to this item: http://ahro.austin.org.au/austinjspui/handle/1/12969
Title: Dissociation of hypoxia-induced calcium gain and rise in resting tension in isolated rat hearts.
Authors: Nayler, W G;Elz, J S;Buckley, D J
Affiliation: Department of Medicine, University of Melbourne, Austin Hospital, Heidelberg, Victoria, Australia.
Issue Date: 1-Apr-1988
Citation: The American Journal of Physiology; 254(4 Pt 2): H678-85
Abstract: When isolated hearts are perfused with substrate-free hypoxic buffer for prolonged periods of time, resting tension and tissue Ca increase. These two events may be interrelated. Isolated rat hearts were used to establish whether the hypoxia-induced increase in tissue Ca can be dissociated from the rise in resting tension. Tension generation was inhibited at the start of hypoxic perfusion by adding 2,3-butanedione monoxime (BDM, 30 mM). In other experiments the Ca2+ in the hypoxic buffer was reduced from 1.3 to 0.1 mM. After 30-120 min of hypoxia, ventricular muscle was assayed for ATP, creatine phosphate, Ca, and Na, and the perfusion defect was established. Resting tension was recorded before and throughout the hypoxic perfusion. Sixty minutes of perfusion with 1.3 mM Ca2+ glucose-free hypoxic buffer caused the tissue Ca to increase (P less than 0.01). Resting tension increased by 7.9 +/- 0.6 g (P less than 0.01). Sixty minutes of perfusion with 0.1 mM Ca2+ glucose-free hypoxic buffer failed to cause an increase in tissue Ca, but resting tension increased (P less than 0.01). During perfusion with glucose-free hypoxic buffer containing 2.6 mM Ca2+ and 30 mM BDM, resting tension remained low for up to 120 min, but after 60 min Ca accumulation occurred. After 120 min of BDM-hypoxic perfusion, tissue Ca reached 11.8 +/- 0.9 mumol/g dry wt. With or without BDM, hypoxia caused an early increase in tissue Na ahead of any increase in tissue Ca.(ABSTRACT TRUNCATED AT 250 WORDS)
Internal ID Number: 3354696
URI: http://ahro.austin.org.au/austinjspui/handle/1/12969
URL: http://www.ncbi.nlm.nih.gov/pubmed/3354696
Type: Journal Article
Subjects: Adenosine Triphosphate.metabolism
Aerobiosis
Anaerobiosis
Animals
Anoxia.physiopathology
Calcium.metabolism
Epoxy Compounds.pharmacology
Female
Heart.drug effects.physiology.physiopathology
Heart Ventricles.metabolism
In Vitro Techniques
Myocardium.metabolism
Perfusion
Phosphocreatine.metabolism
Rats
Rats, Inbred Strains
Sodium.metabolism
Appears in Collections:Journal articles

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