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Biomedical subjects

H Kurihara

Publications and source records attributed to H Kurihara.

At least 379 records · Page 21Linked to original sources
PubMed1977

The content and turnover of norepinephrine in the rabbit brain regions and cardiovascular tissues.

The content and turnover of norepinephrine (NE) in the hypothalamus, midbrain, pons-medulla, mesenteric artery, aorta and left ventricle were studied in the normal rabbit. Turnover rate of NE was determined by measuring the rate of decline in NE content of the tissue after blockade of synthesis with alpha-methyl-p-tyrosine. The NE content of the hypothalamus (1.44+/-0.03 microgram/g) was significantly higher than those of the midbrain (0.25+/-0.01 microgram/g) and the pons-medulla (0.36+/-0.01 microgram/g) (p less than 0.001), whereas the rate constant of NE turnover for the pons-medulla (0.213+/-0.009 hr-1) was significantly greater than those for the hypothalamus (0.164+/-0.008 hr-1, p less than 0.001) and the midbrain (0.180+/-0.008 hr-1, p less than 0.01). In the cardiovascular tissues examined, the NE content was highest in the mesenteric artery (6.33+/-0.19 microgram/g), moderate in the left ventricle (2.08+/-0.10 microgram/g) and lowest in the aorta (0.70+/-0.06 microgram/g). The differences among them were significant (p less than 0.001). However, the rate constant of NE turnover for the aorta (0.119+/-0.014 hr-1) was significantly greater than those for the mesenteric artery (0.059+/-0.008 hr-1, p less than 0.001) and the left ventricle (0.069+/-0.006 hr-1, p less than 0.005). The turnover rate of NE in the mesenteric artery was high, 0.372 microgram/g-hr, which suggests the very active NE synthesis. These results indicate that there are regional differences in content and turnover of NE of the cardiovascular tissues as well as of the brain.

Animals↗
PubMed1976

Difference in changes of plasma volume in two types of Goldblatt hypertension in rabbits.

High plasma renin concentration (PRC) and hematocrit (Ht) were observed in hypertensive rabbits with one renal artery clipped and an intact opposite kidney (Group A), while rather low PRC and Ht in hypertensive ones with one renal artery clipped and the opposite kidney removed (Group B). Plasma volume (PV), blood volume (BV), and packed cell volume (PCV) were estimated in these two types of hypertensive rabbits, and also in sham-operated rabbits (Group C). In Group A, 4 weeks after clipping of a renal artery, PV was decreased and significant inverse correlations were observed between PV and the elevation of blood pressure and between PV and PRC. A significant correlation between PRC and the elevation of blood pressure was also found 4 and 12 weeks after the clipping. PCV was increased until 12 weeks after clipping. In Group B, PV was increased 1 and 4 weeks after clipping, then returned to the initial level. Ht was decreased 1 and 12 weeks, and PCV was decreased 12 weeks after clipping. These results would indicate that a high Ht seen in Group A was partly due to the decreased PV and partly due to the increased PCV, while, in Group B, a low Ht in early stage might be mainly due to the increased PV, but in the late stage, a decreased PCV appeared to play a role to lower Ht. PRC seems to be affected differently by PV in these two types of hypertension.

Animals↗
PubMed1975

Application to a radioimmunoassay for angiotensin I to the measurement of plasma renin in rabbits, and comparison with a biological assay of plasma renin activity.

A radioimmunoassay method for ileu-5-angiotensin I was applied to the measurement of plasma renin in rabbits. In the present method, the volume of plasma sample, required for the determination of plasma renin activity and plasma renin concentration, could be reduced to 0.6 ml and 0.05 ml, respectively. A satisfactory correlation (r = 0.918) was found between the plasma renin activity measured by our bioassay method reported previously and that by the present radioimmunoassay method in each of 25 different plasma samples. A highly significant correlation (r = 0.968) was also observed between the plasma renin activity and the plasma renin concentration, both of which were measured by radioimmunoassays, as far as renin concentration remained under 200 ng/ml/hr. On the other hand, the present results appear to indicate that, when a high plasma renin activity was obtained, it was difficult to evaluate the actual plasma renin concentration. Therefore, it would be necessary to be cautious to apply the method for plasma renin activity on the renin rich plasma.

Angiotensin II↗