[Age related electrophysiological modifications in rat myocardium].

During aging the electrical and mechanical phenomena of the heart are impaired. We studied the effect of aging using standard microelectrode technique on action potentials obtained in papillary muscle from 1, 3, 6 and 18 month old rats. The action potential of myocardial cells is significantly prolonged and changes resemble those observed during cardiac overload.

[An experimental study of the action of 5-fluorouracil on the function and cytomorphology of the exocrine pancreas].

The authors have taken up previous studies by Martin (1969), and by Johnson (1973), and carried out an experimental study on white rats aimed at evaluating the morpho-functional changes of cells from the exocrine pancreas under the influence of 5-fluorouracil (Ftorafur), a cytostatic drug which is a general inhibitor of protein synthesis by cells. Ftorafur was injected in amounts of 2.3 mg/100 g of body weight, and a significant reduction was noted in the secretion of bicarbonates, amylase and lipase by the pancreas of the animals.

Studies concerning the role of myocardial hypertrophy and of intramural tension as determinants of the increased voltage in concentric left ventricular hypertrophy.

In order to study the role of myocardial hypertrophy and of the intramural tension as determinants of the increased voltage in concentric left ventricular hypertrophy, the amplitude of intracellular action potentials in frog and rat myocardium and of monophasic action potentials recorded in dogs by suction electrodes were studied. Increased amplitudes of intracellular action potentials were seen neither in experimental LVH in rats nor during stretch in frog and rat myocardium. The increased intramural tension in dog heart during norepinephrine perfusion or in heart-lung preparation during increased peripheral resistance does not increase the amplitude of monophasic action potentials.