Analysis of the motor effects of gastrin and pentagastrin on the human alimentary tract in vitro

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Demonstration of intercoronary anastomoses in human hearts with a low viscosity perfusion mass

The coronary arteries of 120 nonselected human hearts were perfused with a low viscosity radiopaque medium comprising essentially a suspension of barium sulfate in agar. In each of four groups of 30 hearts, one major artery was perfused, that is, right coronary, left main coronary, left anterior descending trunk, or left circumflex trunk. Anastomoses were detected either by cross-filling of unperfused vessels or by direct stereoscopic visualization. Anastomoses were demonstrable in 84% of the entire series, but the frequency varied between the four groups (right coronary 93%, left main coronary 90%, left anterior descending 90% and left circumflex 60%). The presence of stenotic disease did not seem to affect the frequency of demonstrable stenosis since 84% of the hearts virtually free of arterial disease contained recognizable stenoses as compared with 92% of hearts with a stenosis of more than 50% of the arterial lumen. Neither did age, hypertension or left ventricular hypertrophy produce any alteration in the frequency rates. There were seven hearts with occlusive disease; only five contained demonstrable anastomoses. The 19 hearts in the total series in which anastomoses could not be found were derived from patients, some of advanced age, some young, some having occlusive arterial disease and some hypertension.

The results of the study suggest that anastomoses are present in most hearts unrelated to clinical disease. They may be increased in size or number by factors that affect coronary hemodynamics, but the present study does not investigate this possibility.

The release of 5-hydroxytryptamine from the rat stomach in vitro

1. 5-HT was released into the lumen of the intact isolated rat stomach and into the bath fluid surrounding a preparation of the body and antrum stretched mechanically.2. Release of 5-HT increased when the pressure inside the intact stomach was raised or when the body/antrum preparation was stretched.3. This increased release was not prevented by hexamethonium, atropine, hyoscine or procaine, and was probably due to distortion of cells containing 5-HT.4. During periods of peristalsis induced by transmural stimulation the pharmacological activity of the fluid in the stomach was usually increased owing to a greater release of 5-HT and also to the release of an unidentified substance.5. In reserpine-treated rats, 5-HT was released into the stomach but transmural stimulation did not produce true peristalsis and only rhythmic contractions occurred.6. Peristalsis was seldom reduced by methysergide, and it is concluded that 5-HT is not essential for gastric peristalsis in the rat.