A myocardial blood flow (MBF) in the inner and outer layer of the left ventricle was measured in thoracotomized anesthetized dogs by means of hydrogen clearance method. A recessed type platinum electrode was designed in order to insert easily into the myocardium and to maintain constantly the sensitivity to H2 partial pressure in the myocardium. It was constructed from the platinum wire, 100μ in diameter, covered with a glass which was further enveloped by an injection needle. MBF was calculated from the wash-out curves of hydrogen currents in the platinum electrode tip placed in the left ventricular wall. The values measured by this method were in good agreement with those of coronary sinus blood flow obtained by means of coronary sinus catheter electrode. Hydrogen currents in the inner and outer layer of the left ventricle via a pair of the electrodes and also in the aorta via catheter electrode were simultaneously recorded on the muti-channel recorder. Using this method, the regional MBF during hypoxia, tachycardia or pressure-rise and following the administration of β-stimulating, β-blocking agent or noradrenaline was measured, and the following results were obtained. 1) The average MBF in the inner and outer layer was 112.4 and 98.7ml/100ml/min respectively. Thus, MBF in the former is higher by 21%. 2) Following 6.7% O2 breathing, MBF in the inner layer increased from 106.7 to 175.0ml/100ml /min and that in the outer layer from 72.2 to 145.5ml/ 100ml/min on average. Accordingly I:O ratio (blood flow ratio of inner to outer layer) decreased from 1.48 to 1.25. Under this condition, heart rate and mean aortic blood pressure increased from 127.8 to 142.2 beats/min and 126.6 to 156.4mmHg, respectively. 3) Tachycardia induced by atrial pacing produced a significant augmentation of MBF and I:O ratio was reduced. Aortic pressure-rise produced by angiotensin II (0.2μg/kg/min) did not significantly change the MBF. 4) Isoproterenol (0.3μg/kg/min) produced an increase of the outer layer blood flow without significant change in the inner layer and I:O ratio reduced from 1.31 to 1.00 on average. Propranolol (0.3mg/kg) did not change the MBF in the inner layer but that in the outer reduced by 23.6%, and I:O ratio increased from 1.03 to 1.25. Noradrenaline (1μg/kg/min) produced a remarkable increment of MBF in the inner from 89.1 to 129.3ml/100ml/min, and I:O ratio increased from 1.22 to 1.43.
On the age difference in the changes of female mice hepatic cells caused by cortisone treatment and in the recovery process from them, there have been made some micromeasuring and histochemical studies. In the resting stage, the number of the hepatic cells was fewer in old mice than other younger age groups. In the old aged, decrease in number of hepatic cells after cortisone treatment was more markedly noticed and recovery from it was much slower. The size of the hepatic cells and their nuclei was decreased after cortisone treatment; their decrease was more markedly in the old aged. In the young aged, number of the hepatic cells was rather increased after treatment. On the changing pattern in the process of experimental course after cortisone treatment, there were not distinct differences between middle and old age groups in the size and number of hepatic cells, however, there were noticed some notable differences between younger aged group and other older ones. Succinate dehydrogenase and glucose-6-phosphatase activities were also decreased after cortisone treatment. These decrease recovered rapidly in young and middle age groups but slower in the old aged. The above mentioned discrepancy between micromeasuring data and enzyme-histochemical findings should be discussed after submicroscopical study.
In order to clarify the effect of age on the circulatory system, hemodynamic studies using dye dilution method were performed in 94 healthy individuals of ages 14 to 87 (male 73, female 21) without a history of hypertension, their blood pressure has never exceeded more than 150/90mmHg on repeated determinations. Stroke volume, cardiac output and left ventricular work decreased with age, but heart rate was not correlated with age. On the other hand, total peripheral resistance increased with age. Pulse pressure tended to decrease with age from adolescence to about 45 years and to increase thereafter. These results suggest that the effect of physiological aging on the circulatory system gradually progresses with age, especially the circulatory performance deteriorates about 45 years in Japanese.
Recently, it has been considered that the hypertriglyceridemia may be caused by the impaired TG removal and/or the overproduction of endogenous TG. For detecting disorder of plasma exogenous TG removal, an intravenous fat tolerance test was performed in 12 cases with ischemic heart disease, 9 cases of hyperlipidemia, 4 cases of cerebral arteriosclerosis, 5 cases of diabetes mellitus and 6 cases of normal controls. After overnight fasting, fat emulsion (Intralipid®, 0.15g/kg body weight) was injected intravenously, and exogenous TG in blood samples drawn at 10 minutes intervals were measured to obtain K2 value (fractional removal rate) which was characterized by exponential phase in elimination curve of the plasma exogenous TG. As results it was found that the statistically reverse correlationship between K2 values and plasma lipid levels, particularly TG levels, was there. Although plasma cholesterol levels were not in good relation to K2 values, in hypercholesterolemic patients, even though they had normal TG levels, decreased K2 values were found. The average K2 value in ischemic heart disease was lower than this in the other subjects, also noticed was that some normolipemic subjects with ischemic heart disease and/or obesity had lower K2 values. In conclusion, it seems that the impaired plasma TG removal in peripheral vessels may be one of the causes of hypertriglyceridemia i. e. an atherogenetic factor.
To study factors responsible for the development of cerebrovaseular disease (CVD), comparison of cross-sectional population survey was performed in two neighboring towns in Akita prefecture, Yuwa and Tenno, where the age-adjusted death rates of CVD were significantly different. The death rates of CVD were 361/100, 000 population in Yuwa and 219/100, 000 population in Tenno. The results obtained in two towns were as follows. 1) Yuwa population trended to have the higher systolic blood pressure than Tenno. This was particulary significant in the fourth decade for males, and in the fourth to seventh decades for females. 2) On ECG, the findings of left ventricular hypertrophy, which might be attributed to hypertension, were more frequently observed in the fourth, sixth and seventh decades of Yuwa population. 3) There were no differences in the values of serum cholesterol, phospholipid and triglycerides between two towns. 4) The ratios of linoleic acid to oleic acid (L/O) were significantly lower in the fourth to seventh decades for males and in the fourth to fifth decades for males in Tenno, where the deaths of CVD were lower than in Yuwa. 5) Serum uric acid was higher in fourth to seventh decades for males and in the fourth to fifth decades for females in Tenno. This may be due to differences in taking of dietary protein and fat between Tenno and Yuwa. 6) The frequency of the calcification in the carotid siphon observed on the plain skull radiogram increased with ages in both towns. There were no differences in the frequency of the calcification of the carotid siphon and the sclerotic changes of the ocular fundi between two towns. These results suggest that abnormalities of serum lipid, which has been considered as risk factors for CVD, may not be of predictive value with regard to the development of CVD in Akita. On the other hand, it was assurmed that the most potent factor responsible CVD might be the rising of the blood pressure.
A study was showed that plasma fibrinogen might play an important role of diabetes mellitus with vascular complications. 100 cases in untreated diabetics were chosen. The blood sample was taken after overnight fasting and serum lipids fraction (cholesterol, neutral fat and free fatty acid) and plasma fibrinogen content were measured immediatly. When compared with normal healthy group, the diabetic group had high concentration of serum lipids and plasma fibrinogen. Especially the level of serum lipids in all diabetics showed a statistically significant increase from normal. The diabetics were classified into three groups according to the kind of vascular complications in diabetes. The plasma fibrinogen increased in all patients with one or other kinds of vascular diabetic complications. And the group with microangiopathy in whom diabetic retinopathy and nephropathy were included, had higher fibrinogen concentration than the diabetics without complication. Further higher level of fibrinogen was noticed significantly in the group with cardiovascular complication that was represented as clinically hypertension and ischemic heart disease. The markedly higher increase of fibrinogen was proved to the complicated group with both microangiopathy and cardiovascular complication. In the case accompaning vascular complication in diabetes, it was stated that the level of plasma fibrinogen was increasing more than that of the non-complicated group. Therefore it was suggested that a rate of fibrinogen increment might reflect the characteristic condition of vascular complication in diabetes. It was carried out to clarify a correlation between serum lipids levels and vascular complication in diabetes. The increase of neutral fat in serum lipids was closely related to the presence of vascular complication with both microangiopathy and cardiovascular complication, in spite of the evidence that cholesterol in all diabetic patients was raised higher value than normal. From the above, it was concluded that the course of vascular complication in diabetes had distinctly followed the increase of plasma fibrinogen rather than the serum lipids. This finding was interesting fact for the pathogenesis of vascular complication in diabetes mellitus. And it was emphasized that the measurement of plasma fibrinogen was useful to know the prognosis on vascular complication in diabetes mellitus.
Intestinal metaplasia in chronic gastritis is known to appear with high frequency together with atrophic change, and is thought to be one of the major changes occurring in chronic gastritis. However, since intestinal metaplasia is generally difficult to confirm clinically, even in this age of improved diagnostic techniques, there are a number of aspects of intestinal metaplasia which are still not clearly understood. As a means of understanding the pathological condition of intestinal metaplasia, we approached the problem from the view point that the frequency of intestinal metaplasia increases with age. The study centered on the spread of intestinal metaplasia in relationship to age. The reseach was based on a study by specimens of chronic gastritis in portions of the stomach which had been surgically removed and bioptic specimens taken of chronic gastritis by the dozen biopsy technique. The study confirmed that intestinal metaplasia spreads as age increases but also indicated that it spreads most rapidly between the ages of 31 and 40 or above 51. In addition, the study indicated that intestinal metaplasia was most likely to develop three or four centimeters from the opening of the pyloric ring on the lesser curvature. It may be inferred that intestinal metaplasia increasing upward along the lesser curvature, as well as toward the anterior and posterior walls and also toward the pyoric ring.