Kymographical recordings of acute effects of sinoaortic denervation on blood pressure in spontaneously hypertensive rats and normotensive Wistar rats revealed that the former showed a significantly greater pressor response than the latter after the denervation even at the age of 30-60 days, at the age corresponding to the prehypertensive stage while there was no significant difference in the pressor response between the former and the latter at the adult age. These results provide an evidence that primary defect or dysfunction of baroreceptors is not involved in the pathogenesis of spontaneous hypertension, and are rather suggestive of primary activation of vasomotor center as one of the probable causes of this hypertension.

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Separation of the neural connection between posterior hypothalamus and mesencephalon with a special knife elicited abruptly a slight but prolonged fall in blood pressure in normotensive Wistar rats (-18±5 mmHg), while other separations in the hypothalamus or between hypothalamus and other brain structures were ineffective. This fall of blood pressure was significantly greater in Spontaneously Hypertensive Rats (-34±11 mmHg). These facts favoured the evidence of hypothalamic tonic influence to blood pressure regulation and its participation in the pathogenesis of the spontaneous hypertension.

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Experiment was undertaken to evaluate the immediate effects of internal mammary artery implantation by measuring contractility, left ventricular movement or configuration, and myocardial oxidative metabolism before and immediately after in 34 dogs. The results indicated that the new extracoronary blood supply carried by implantation improved the contractility and the oxidative metabolism in the myocardium immediately to a measurable extent, and that the myocardial revascularization by implantation had an immediate therapeutic value.

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For the elucidation of the pathogenesis of the diabetic vascular complication, direct chemical analysis of mucosubstance, which characterize the specific lesion of this complication, were attempted in this study. Renal glomeruli, which were isolated from the kidney obtained at autopsy by the Krakower's method, were digested with Pronase-p. Released polysaccharides and glycopeptides were isolated and fractionated with Sephadex column. From normal glomeruli, two fractions of glycopeptides were obtained. Increased amount of both fractions of glycopeptides was noted in diabetic glomerulosclerosis, but no qualitative changes were observed in diabetics and nondiabetics. Total acid mucopolysaccharide content in glomeruli were also increased in diabetic glomerulosclerosis and remarkable changes were observed in the distribution of their fraction. From these data nature of mucosubstances in diabetic glomerulosclerosis was discussed.

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A learning machine "adaline neuron" was employed for automatic diagnosis of the vectorcardiogram and the electrocardiogram. The frontal circle and the horizontal circle were divided into 480 meshes. The features were expressed by a binary digit, whether the vector loops passed through each mesh or not. In a part of the trials, 5 sets of binary digits were applied in addition to QRS duration and direction of inscription of QRS loops and T loops. In this trial a total of 490 meshes were used. Vectorcardiograms were taken by FRANK'S method in 235 cases. Several methods of adaline usage were tried. The best result was obtained so far by successive dichotomies based on the principle of the logical decision tree. First the normal patterns and the abnormal patterns were divided. The correct ratio was 96.5% when the 490 meshes were employed, cases of an output value within ±10 units being regarded as undecided. Next the abnormal cases were divided into two groups depending on whether the QRS duration was more than 0.12 seconds or less. The group of cases with a QRS duration of less than 0.12 seconds was divided into right ventricular hypertrophy and others. The correct ratio was 98.6%. The remaining cases were divided into left ventricular hypertrophy and myocardial infarction, the correct ratio being 88.8%. The group of cases with a QRS duration of more than 0.12 seconds was easily divided into complete left and right bundle branch block in all cases. Here the number of meshes could be decreased to 59 meshes without changing the accuracy appreciably. This attempt showed that the application of the adaline for automatic diagnosis of the vectorcardiogram and the electrocardiogram is promising.

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1. Both acid angiotensinase and calcium-dependent neutral angiotensinase are widely distributed among various tissues of the rat. High activity of acid angiotensinase in such lysosome-rich tissues as kidney, spleen and liver suggests localization of this enzyme in lysosomes. 2. Main angiotensinases in rat liver are concentrated in lysosomal and soluble fractions. The lysosomal enzyme which is inhibited by DFP is acid angiotensinase, while the other is calcium-dependent neutral angiotensinase. 3. The pH optimum of lysosomal angiotensinase of the kidney is 5.6-5.7. Properties of acid angiotensinase indicate that a carboxypeptidase, so-called angiotensinase C, is a lysosomal eazyme and plays a main role in lysosomal angiotensinase activity. On the other hand, partial inhibition and activation by p-chloromercuribenzoate and dithiothreitol imply that some other enzyme(s) may take part in this activity. 4. Acid angiotensinase of kidney lysosomes was separated from arylamidase and hemoglobin-splitting cathepsin by Sephadex gel-filtration. Cathepsin A activity, however. Could not be eliminated from the acid angiotensinase by either Sephadex gel-filtration or DEAE-cellulose Column chromatography. DFP showed an inhibitory effect on cathepsin A activity of kidney lysosomes. 5. Molecular weight of lysosomal acid angiotensinase of rat kidney is between 70, 000 and 90.000, calculated by Sephadex gel-filtration. 6. Possible role of the lysosomal enzyme in angiotensin metabolism in vivo is discussed.

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A 58-year-old male who recited Chinese poems for more than 40 years and had arrhythmia for more than 20 years showed second degree sinoatrial heart block with the Wenckebach phenomenon·at rest. The arrhythmia was complicated by nodal escape and second degree atrioventricular block. The arrhythmia disappeared after muscular work and reappeared after more than 10 minutes of rest in a sedentary or recumbent position. It disappeared also after an injection of 0.5 mg of alotec(isoproterenol derivative). Functional and adaptive natures of the arrhythmia were indicated.

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