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Biomedical subjects

A Ooshima

Publications and source records attributed to A Ooshima.

At least 145 records · Page 8Linked to original sources
PubMed1980

Hypertension, vasculature and aging.

Essential hypertension is the most common disease which develops with advancing age, and its complication, arteriosclerosis, seems to be an exaggerated form of aging process in the mesenchymal tissues. Our present investigation demonstrated that deposition of collagen fibers in vessel wall may represent one aspect of the aging phenomenon occurring in normal vasculature.

Aging↗
PubMed1980

Effect of beta-receptor-blocking agents on cardiovascular structural changes in spontaneous and noradrenaline-induced hypertension in rats.

1. Continuous intravenous noradrenaline infusion for 1 week into rats by osmotic minipumps significantly increased blood pressure and left ventricular weight. 2. Concomitant alpha-receptor-blockade infusion significantly lowered blood pressure and the aortic weight without significant reduction in left ventricular weight. 3. Two beta-receptor-blocking agents in noradrenaline-infused rats normalized left ventricular weight and significantly reduced the aortic weight, although blood pressure was still higher than control non-infused rats. 4. In 7-week-old spontaneously hypertensive rats, propranolol (perorally for 2 weeks) did not lower blood pressure but reduced significantly cardiovascular protein synthesis ([14C]lysine and [3H]uridine incorporation into non-collagen protein and RNA respectively) in both left ventricle and aorta. This effect was in contrast to hydralazine, which normalized blood pressure but did not reduce cardiovascular protein synthesis. 5. Results suggest that beta-receptors play a modulating role in the structural cardiovascular response to blood pressure.

Animals↗
PubMed1980

Abnormal membrane characteristics of erythrocytes in rat models and men with predisposition to stroke.

Erythrocyte membrane characteristics were examined in normotensive Wistar-Kyoto rats (WK), stroke-resistant spontaneously hypertensive rats (SHRSR) and stroke-prone SHR (SHRSP). The membrane of SHRSP was more labile against osmotic shock than that of SHRSR or WK at the age of 2 months. This membrane fragility was not dependent on their blood pressure. The membrane permeability of lipophilic ion, tetraphenylphosphonium, was increased in 1-month old SHRSP. These membrane characteristics in SHRSP were partially dependent on cholesterol amount which was significantly decreased in SHRSP. The method determining the membrane fragility was applied to human erythrocytes. Two groups of people were selected from about 2,000 inhabitants under our community health control program. The erythrocytes from the group with stroke in their family history were more labile than erythrocytes from the corresponding group without stroke in their family history. This result suggests that the examination of these membrane characteristics may give us a new method to detect a genetic risk to hypertension or stroke-proneness also in human.

Adult↗
PubMed1979

Cardiac hypertrophy in early hypertension.

Studies of cardiac hypertrophy in spontaneously hypertensive rats have indicated that left ventricular hypertrophy occurred even in the prehypertensive stage. These findings suggested that other factors besides blood pressure levels, and including possibly a genetic predisposition to myocardial hypertrophy, could play a role in structural cardiovascular alterations in spontaneously hypertensive rats. More recent studies have confirmed these anatomic results; left ventricular hypertrophy was vectorcardiographically detected even in the prehypertensive stage in voth young stroke-prone rats and stroke-resistant spontaneously hypertensive rats. Further, a close relation was found between degree of left ventricular hypertrophy and vascular hypertrophy or hyperplasia; this suggests that early detection of left ventricular hypertrophy may be a useful indicator of the incipient stage of structural vascular changes in genetic hypertension.

Adrenergic beta-Agonists↗
PubMed1979

Biochemical alterations of connective tissue metabolism in the arterial walls of stroke-prone spontaneously hypertensive rats.

1. The chemical characteristics of the vascular connective tissue components were determined in stroke-prone (SP), stroke-resistant (SR) spontaneously hypertensive (SH) rats and normotensive Wistar-Kyoto (WK) rats. 2. The ratio of hydroxylysine to hydroxylsine plus lysine in the vascular collagen was increased in 6-month-old SP-SH rats and SR-SH rats as compared with WK rats. 3. An age-related increase in uronic acid and hexose content of the aorta was noted in SP-SH, SR-SH and WK rats. However, the increase was more prominent in SH rats, especially SP-SH rats at the stages examined (11 weeks and over 8 months of age). 4. The ratio of galactosyl-hydroxylysine to glucosyl-galactosyl-hydroxylysine in the aortic collagen was decreased in 6-month-old SH rats, especially SP-SH rats as compared with WK rats. 5. A relative increase in beta and gamma components in aortic collagen was noted in 6-month-old SP-SH rats when compared with SR-SH rats. 6. The increased content of uronic acid and hexose and the structural changes of vascular collagen as demonstrated in SP-SH rats might be related to the fragility of the arterial wall and/or to the pathogenesis of stroke-proneness.

Aging↗