Arterial endothelium-derived relaxing factor (AEDRF) does not suppress papillary muscle or portal vein contractions.

10(-6) M EDRF released from perfused arterial donor segments in a superfusion bioassay system, either spontaneously or stimulated by acetylcholine, did not inhibit the contractility of electrically stimulated right ventricle papillary muscle of pig, rabbit and rat. EDRF also did not inhibit spontaneously contracting rat portal vein and thus relaxed precontracted arterial rings denuded of endothelium. The results suggest that EDRF released by arterial endothelial cells is a local modulator of arterial smooth muscle and is not important for extraarterial tissue regulation.

The primary sequence of human pancreatic colipase.

The amino acid sequence of an activated colipase purified from human pancreas was determined. The protein consists of a single polypeptide chain of 86 amino acids (human colipase86) and has a molecular weight of 9289. The sequence was determined by automated Edman degradation of the reduced and S-carboxymethylated protein and of two CNBr peptides. Sequence determination of porcine procolipase II was also performed, which showed that in the original sequence determination apparently two residues were missed. These residues were determined to be a leucine at position 37 and a serine in position 50. For comparison with porcine and equine procolipases, the residues composing human colipase are numbered from 6 to 91. No human procolipase has been isolated so far. The colipases from man, pig, horse and chicken show a high degree of homology: human colipase differs from the other proteins by substitutions of 19 (porcine), 24 (equine A) and 21 (equine B) residues, respectively.

Atherosclerosis of the aorta in five towns.

Fatty streak was always present in both the thoracic aorta and the abdominal aorta in the youngest subjects studied (aged 10-14 years). Fibrous plaque was present in a small proportion of these young subjects, but a rapid increase in prevalence occurred as early as the fourth decade. Complicated and calcified lesions appeared as early as the age of 20-25 years but a rapid increase in prevalence was seen after age 40 for complicated lesions and after age 50 for calcified lesions. There were differences in the prevalence of severe lesions among the five towns. There was little increase in the extent of atherosclerosis in the thoracic aorta before the age of 40 and in the abdominal aorta before the age of 20. The increase was more rapid after those ages. When atherosclerosis had affected about 50% of the intimal surface of the thoracic aorta and 70% of the intimal surface of the abdominal aorta, the increase slowed down considerably. In contrast to other types of lesion, the extent of fatty streak increased only up to 30 years of age, when it occupied 25-30% of the intimal surface. Then it declined and in the older age groups did not exceed 4-5% in men or women. The extent of fibrous plaque and complicated lesions was at all ages greater in men than in women, while the extent of fatty streak and calcified lesions in older age groups was greater in women. There were marked differences in the extent of atherosclerotic lesions in the five towns.

High and low atherosclerosis groups.

Aortic and coronary atherosclerosis were studied in two groups, the "high atherosclerosis group" and the "low atherosclerosis group". The latter may be considered as showing basic levels of atherosclerosis in the different communities. The development of lesions in the two groups occurred in parallel, but earlier in the high group. Sex differences in the two groups were similar to those in the whole material. Generally speaking, inter-town comparisons were similar in each group and similar to those for deaths from all causes, a notable exception being the prevalence of coronary stenosis. The findings indicate that the groups can be used as reference groups, but only for material drawn from the same source.

Atherosclerosis and hypertension.

Autopsy studies of atherosclerosis of the aorta and the coronary arteries were carried out in 3134 subjects with essential hypertension. A comparison was made with low, average, and high atherosclerosis groups. Essential hypertension was found to accelerate the development of all types of aortic lesion, except fatty streak, as compared with the standardized average atherosclerosis group, and to accelerate the development of fibrous plaque but not complicated and calcified lesions as compared with the high atherosclerosis group. The extent of fibrous plaque in the coronary arteries was greater in the essential hypertension group than in the low and standardized average atherosclerosis groups but did not differ from that in the high atherosclerosis group. The extent of complicated and calcified lesions and the prevalence of coronary stenosis were higher in the high atherosclerosis group than in cases of hypertension. Geographical differences in atherosclerosis among hypertensives in different towns reflected the findings for the whole material. Symptomatic hypertension was found to accelerate aortic atherosclerosis at least to the same extent as essential hypertension. It was conductive to coronary atherosclerosis but not to the same extent as essential hypertension. Coronary stenosis and various manifestations of coronary heart disease were rare in symptomatic hypertension.

Atherosclerosis and diabetes mellitus.

Diabetes mellitus occurred most frequently in Prague (8.4%) and Malmö (8.6%), and less often in Tallin (3.4%), Yalta (3.3%), and Ryazan (2.1%), these differences not being connected with differences in age distribution. The extent of raised and calcified lesions in the coronary arteries and calcified lesions in the aorta in the pure diabetes group was similar to that in the high atherosclerosis group and significantly higher than in the standardized average atherosclerosis group. Raised and calcified lesions in the aorta and raised lesions in the coronary arteries were more extensive in the diabetes group than in the high atherosclerosis group. In all diabetes groups, stenosis of the coronary arteries and myocardial lesions occurred much more frequently than in the average atherosclerosis group but were less common than in the high atherosclerosis group. Coronary thrombosis also occurred more frequently in the high atherosclerosis group. Diabetes per se and hypertension were found to have approximately the same effect on the development of atherosclerosis, but hypertension had a greater effect than diabetes on the development of aortic atherosclerosis. There were no significant differences in the frequency of coronary stenosis and myocardial lesions in diabetics and hypertensives. Diabetics of more than 10 years' standing generally showed more coronary but not more aortic atherosclerosis than those who had had diabetes for less than 10 years. In insulin-treated diabetics coronary atherosclerosis tended to be more extensive than in those treated by diet or by tablets, but there was no difference in the frequency of coronary stenosis and thrombosis and myocardial and cerebrovascular lesions.

Atherosclerosis of the aorta and coronary arteries in coronary heart disease.

Aortic and coronary atherosclerosis and the prevalence of coronary stenosis and thrombosis were studied in subjects who had died of fresh or recurrent myocardial infarction or had suffered from myocardial infarction in the past. In general, severe atherosclerosis of the coronary arteries with stenosis and calcification was almost a prerequisite for the development of coronary heart disease. The frequency of coronary heart disease varied widely both in different countries and in different towns in the same country. Considerable variations were found among the various towns in the frequency of stenosis and thrombosis in those who had died of coronary heart disease. This finding indicates that although atherosclerosis is indeed a prerequisite for the development of myocardial infarction, other factors may play a significant role in its occurrence. The weight of the heart in persons (excluding hypertensives) with coronary stenosis or a first fresh myocardial infarction was considerably greater than that in the low atherosclerosis group.