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Biomedical subjects

J Fujii

Publications and source records attributed to J Fujii.

At least 325 records · Page 18Linked to original sources
PubMed1977

Responses of plasma renin to sodium load in two types of experimental renal hypertension.

A sodium-rich diet was given 20 rabbits with 2-kidney hypertension (clipping of one renal artery with an intact contralateral kidney), 19 rabbits with 1-kidney hypertension (clipping of one renal artery with contralateral nephrectomy), and 13 normal rabbits. Sodium content of the diet was twice as much as the regular diet. The sodium load was started 10 weeks after clipping of the renal artery and lasted for 2 weeks. During the sodium load blood pressure did not show any significant changes but hematocrit was reduced in all 3 groups. Plasma renin activity (PRA) was clearly suppressed in 10 of 19 animals with 1-kidney hypertension and in 6 of 13 normal animals, but only in 4 of 20 animals with 2-kidney hypertension (p less than 0.04). The results indicate that PRA was more easily suppressed in animals with 1-kidney hypertension than in those with 2-kidney hypertension by a sodium-rich diet and the suppressive response is not associated with alterations in blood pressure.

Animals↗
PubMed1977

Increase of hematocrit in experimental renal hypertension and its reversal.

Hematocrit can be increased in experimental animals with renal hypertension of two-kidney type. The present study showed that the increased hematocrit was returned to normal by removal of the clipped kidney. The left renal artery was clipped in 13 rabbits with an intact contralateral kidney, and a sham operation was performed in 10 rabbits as a control. After an interval of 10 weeks the left kidney was removed in all animals. Blood pressure, hematocrit, hemoglobin content, and erythrocyte count were rapidly increased and remained raised after clipping of the renal artery but they did not show any significant changes after sham operation. A transient but significant increase of reticulocyte count was found at the end of the first week after clipping of the renal artery. Removal of the clipped kidney was followed by a rapid return of hematocrit, hemoglobin content, and erythrocyte count to normal within 2 weeks. Blood pressure was also decreased but not returned to normal by removal of the clipped kidney.

Animals↗
PubMed1977

Peri-ureteric collateral vessels in rabbits with experimental renal hypertension.

The development of collaterals to an ischemic kidney was studied in rabbits with two-kidney Goldblatt hypertension. Hypertension was produced by applying a silver clip of 0.9 mm in internal diameter on the left renal artery with the right kidney intact. Peri-ureteric collaterals were found at autopsy in 27 (32.9%) of 82 animals that were killed 7 days (early stage) and in 30 (40.5%) of 74 animals that were killed in more than 70 days (late stage) after clipping. The average blood pressure was 123.8 +/- 2.6 (SE) mmHg in animals with collaterals vs. 125.3 +/- 2.1 mmHg in animals without them in the early stage, and 142.5 +/- 4.4 mm Hg in animals with collaterals vs. 122.6 +/- 3.3 mmHg in animals without them in the late stage. These results indicate that the collaterals to an ischemic kidney develop independently of the rises in blood pressure during the first week and the presence of collaterals is associated with moderate to severe hypertension in the late stage.

Animals↗
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

Detection of the site and extent of the left ventricular asynergy in myocardial infarction by echocardiography and B-scan imaging.

The left ventricular wall motions in 53 patients with myocardial infarction and 14 normal subjects were studied by echocardiography and B-scan imaging (ultrosono-cardiokymography, ultrasono-cardiotomography). (1) Abnormal left ventricular wall motions corresponding to the electrocardiographic sites of infarction were seen in the echocardiograms in 80 % of total patients and 100 % of acute cases. Exaggerated wall motion in opposing noninfarcted areas was seen in 50 % of acute cases and 10 % of old cases. Quantitative analysis of asynergy could be made by comparing PWE, SE and those ratios to EDD-ESD of infarcted hearts with those of normal hearts. (2) In acute myocardial infarction, abnormal motions of left ventricular wall are marked in acute phase and diminished in extent gradually in recovery phase. But in some cases, echo-demonstrated segmental dyskinesis did not disappear in recovery phase, possibly due to the presence of irreversible myocardial damage. (3) Echographic thickness of the infarcted wall was less increased then normals or was not increased during systole and decreased when bulged out in some cases, indicating the existence of necrotized muscle. Moreover, multiple echoes sometimes seen between endocardial and epicardial echoes of infarcted myocardium were considered to display the fibrosis of the infarcted myocardium. (4) Abnormal echocardiographic motions of septum and posterior wall were observed in some cases who had no electrocardiographic abnormalities which suggest septal or posterior wall involvement. Echocardiography could detect another affected area of the left ventricle which could not be detected by electrocardiography. (5) Echocardiography in combination with B-scan imaging (UCKG, UCTG) can detect not only the location, but also the size and extent of myocardial infarction. (6) The results of this study indicate that echocardiography and B-scan imaging (UCKG, UCTG) are sensitive methods in detecting the size and location of asynergy and making a precise diagnosis of myocardial infarction. But it is necessary to distinguish abnormal septal and posterior wall motions observed in right ventricular volume overload, complete LBBB or PMD(COCM) from those of myocardial infarction.

Echocardiography↗
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↗
PubMed1974

Effect of removing the clipped kidney on renovascular hypertension in rabbits.

Constriction of one renal artery in the presence of the opposite kidney can produce persistent hypertension which is often associated with increase in plasma renin activity, decrease in serum potassium and increase in water intake. In the present study the clipped kidney was removed in 15 hypertensive rabbits 12 to 54 weeks after the constriction. Blood pressure showed a prompt and transient fall which was followed by a slight rebound and subsequently a gradual decline. However, it still remained above the normal 5 weeks after removal. Removal of the clipped kidney resulted in return to normal of increased plasma renin activity, decreased serum potassium and increased water intake at the end of the postoperative first week.

Animals↗