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R A Altschuld

Publications and source records attributed to R A Altschuld.

75 records · Page 5Linked to original sources
PubMed1969

Anaerobic performance and metabolism of the hyperthyroid heart.

Anaerobically periused hearts from rats with experimentally induced hyperthyroidism exhibited accelerated deterioration of pacemaker activity and ventricular performance. The diminished anaerobic performance of hyperthyroid hearts was associated with decreased adenosine triphosphate (ATP) levels and a reduced rate of anaerobic glycolysis as reflected in decreased lactic acid production during 30 min of anoxic perfusion.Studies on whole heart homogenates demonstrated inhibition at the phosphofructokinase (PFK) step of the glycolytic pathway. Such inhibition was not demonstrated in the hyperthyroid heart cytosol. It is postulated that an inhibitor of PFK which resides dominantly in the particulate fraction is probably responsible for the diminished anaerobic glycolysis and performance of the hyperthyroid heart.

Adenosine Triphosphate↗
PubMedDate not supplied

Nucleotide profiles in normal minipig arterial tissue.

The purpose of this study was to characterize the nucleotide profiles of a normal porcine elastic and muscular artery. Tissue samples (50 to 150 mg) were excised from the descending thoracic aorta and from the femoral artery of 14 normocholesterolemic, anesthetized minipigs. In three animals, transmural myocardial samples were also obtained. Nucleotide and nucleoside concentrations were analyzed by using a recently developed ion-pairing, reverse-phase, high-performance liquid chromatographic method. The arterial samples contained relatively low concentrations of adenosine triphosphate, approximately one-eighth that of the myocardial counterpart. Relative to the femoral artery, the aortic samples had significantly lower adenylate energy charges and higher levels of adenosine diphosphate, adenosine monophosphate, adenosine, and inosine. These baseline aortic levels did not change after in vitro exposure to 95% oxygen. The different energy states observed in the two arteries may reflect functional or metabolic differences in their medial smooth muscle cell populations. Alternatively, the lower energy state observed in the thicker walled aorta may be a manifestation of inadequate medial oxygen delivery that persists despite oxygen enrichment in vitro. We conclude that arterial energy states exhibit regional variation. This information will serve as a point of departure for the investigation of the role energy states may play in the atherosclerotic process.

Animals↗