Biomedical subjects

H Urata

Publications and source records attributed to H Urata.

86 records · Page 5Linked to original sources

PubMed1989

Mild exercise therapy increases serum high density lipoprotein2 cholesterol levels in patients with essential hypertension.

In ten patients with essential hypertension who were on a prescribed regimen of supervised mild exercise, we examined serum lipids, HDL cholesterol subfractions (HDL2 and HDL3), and apolipoproteins. The findings were compared with data on age- and sex-matched hypertensives not on this regimen of exercise. Blood samples were obtained from the auricle during the multistage exercise test, and changes in levels of lactate were measured. The exercise was done for 30 minutes three times weekly for 10 weeks. A significant reduction of both systolic and diastolic blood pressure was evident at 10 weeks. Serum concentrations of HDL2 cholesterol increased significantly at 10 weeks, but there were no changes in total and HDL3 cholesterol. No significant changes were observed in serum concentrations of total cholesterol, triglyceride, and apolipoproteins, (apo) A-I, apo A-II, apo B, apo C-II, apo C-III and apo E following 10 weeks of exercise therapy. In the hypertensive controls who were not on exercise therapy, blood pressure as well as all parameters related to lipoproteins remained unchanged. Thus, mild exercise lowers blood pressure and improves the lipoprotein profile.

Adult↗

PubMed1989

Angiotensin II receptors in normal and failing human hearts.

To demonstrate the existence and help clarify the function of angiotensin II (Ang II) receptors in the human heart, we characterized the cardiac Ang II receptor and examined the levels and distribution of ventricular Ang II receptors in normal (n = 6) and failing (n = 14) hearts. Ang II receptors were characterized using the Ang II receptor agonist [125I]Ang II. Cardiac [125I]Ang II-binding sites were of high affinity (Kd, approximately 1 nmol/L) and low capacity (Bmax, approximately 3 fmol/mg membrane protein) and were pharmacologically specific [IC50 values for Ang II, [Sar1,Ile8]Ang II, and Ang III were 1.2, 3.0, and 400 nmol/L, respectively; the inactive Ang II metabolite Ang-(1-5), at a concentration of 1 mumol/L, inhibited [125I]Ang II binding by less than 10%]. These characteristics of cardiac [125I]Ang II-binding sites are similar to those of previously characterized mammalian heart Ang II receptors. In normal adult donor hearts (n = 5), Ang II receptor density in the left ventricle [LV, 2.90 +/- 1.40 (+/- SE) fmol/mg] was similar to that in the right ventricle (RV, 3.82 +/- 1.10 fmol/mg). The ventricular Ang II receptor density in adult patients with idiopathic (LV, 1.77 +/- 0.35 fmol/mg; RV, 1.58 +/- 0.29 fmol/mg; n = 8) or dilated cardiomyopathy (LV, 2.00 +/- 0.58 fmol/mg; RV, 2.56 +/- 0.52 fmol/mg n = 5) was similar to that in the normal heart. Ventricular Ang II receptors, localized by autoradiography using the Ang II receptor antagonist [125I]-[Sar1,Ile8]Ang II, were consistently found in the myocardium, cardiac adrenergic nerves, and coronary vessels of normal and failing ventricles. In human ventricles Ang II receptor levels were not correlated with age. Because ventricular Ang II receptor density in a normal neonatal human heart and that in a heart from an adolescent patient with idiopathic cardiomyopathy were more than 10-fold and more than 5-fold higher, respectively, than in normal adult ventricles, we investigated whether postnatal changes occur in ventricular Ang II receptors in rats. In male and female rats ventricular Ang II receptor density was about 2-fold higher in 1-day-old rats compared to that in 10-day-old or peripubertal rats. These data suggest developmental regulation of ventricular Ang II receptors. Our findings suggest that direct and neural angiotensinergic inputs to the myocardium play a role in the regulation of cardiac function in man and that these inputs are preserved in the failing heart.

Adolescent↗

PubMed1989

Changes in serum concentrations of taurine and other amino acids in clinical antihypertensive exercise therapy.

Thirty-one Japanese with essential hypertension were divided into training (n = 21) and non-training (n = 10) groups. Physical training of 10 weeks was instituted after 4 or more weeks of observation, and changes in blood pressure and serum concentrations of taurine and other amino acids were investigated. The workload in physical training was predetermined by the submaximal multistage graded exercise test on a bicycle ergometer, and the blood lactate threshold which reflects approximately 40-60% of maximal oxygen uptake was chosen. The hypertensive patients underwent bicycle ergometer training for 60 minutes, three times a week for 10 weeks. Blood pressures were significantly decreased by 14.8/6.6 mmHg in systole/diastole in the training group, but not in the non-training group. Serum concentrations of taurine and cystine were increased significantly by 26% and 287%, in the training group. Increase in serum asparagine (11%), histidine (6%) and lysine (7%) concentrations was also significant, only in the training group. Plasma norepinephrine level and whole blood and plasma volumes were significantly reduced. The change in serum taurine level was significantly negatively correlated with the change in plasma norepinephrine. In addition there was a significant positive correlation between the change in plasma norepinephrine and the change in diastolic blood pressure in the training group. Based on these results, the increase in serum taurine which is known for its antihypertensive activity could contribute, at least in part through the reduction in plasma norepinephrine level, to the antihypertensive effect of exercise.

Adult↗

PubMed1988

Evidence for extracellular, but not intracellular, generation of angiotensin II in the rat adrenal zona glomerulosa.

Based on the observation that high levels of renin and angiotensin II (Ang II) are found in the adrenal zona glomerulosa (ZG), it has been postulated that Ang II is formed intracellularly by the renin-converting enzyme cascade in this tissue. To test this hypothesis, we examined renin-angiotensin system components in subcellular fractions of the rat adrenal ZG. Renin activity and immunoreactive-Ang II (IR-Ang II) were observed in vesicular fractions but were not colocalized. In addition, angiotensinogen, angiotensin I, and converting enzyme were not observed in the renin or IR-Ang II-containing vesicular fractions. These data do not support the hypothesis that Ang II is formed intracellularly within the renin-containing vesicles of the ZG. Rather, since modulatable renin release from adrenal ZG slices was observed and renin activity was found in dense vesicular fractions (33-39% sucrose), it is likely that Ang II formation in the ZG is extracellular and initiated by the release of vesicular renin. Receptor-mediated endocytosis and subsequent degradation of Ang II in ZG lysosomes have been shown by others. The presence of IR-Ang II in light vesicular fractions (15% sucrose) and the finding of a high correlation between ZG IR-Ang II and Ang II receptor levels suggest that the primary occurrence of this peptide in the ZG is by receptor-mediated endocytosis. In ZG lysosomal fractions 125I-labeled Ang II was degraded to 125I-labeled des-[Phe8]Ang II. Since Ang II antibodies do not recognize des-[Phe8]Ang II, these findings explain why IR-Ang II in the ZG is due predominantly to Ang II and not to its C-terminal immunoreactive fragments.

Adrenal Cortex↗

PubMed1988

What types of hypertensives respond better to mild exercise therapy?

Twenty-one patients with essential hypertension were treated with aerobic (lactate threshold) exercise (n = 21) and the change in blood pressure was compared with that in a non-exercising hypertensive control group (n = 10). After 10 weeks of exercise therapy blood pressure in the exercise group was significantly reduced, from 154 +/- 3/100 +/- 2 to 141 +/- 3/93 +/- 3 mmHg, and there was a significant reduction in plasma volume, cardiac index and plasma noradrenaline whereas there were no changes in the non-exercise group. Responders (10 mmHg or more fall in mean blood pressure) in the exercise group had a significantly higher cardiac index, serum Na:K ratio and lower total peripheral resistance in pretraining studies than non-responders. In conclusion, exercise at lactate threshold is effective in lowering blood pressure in those mild hypertensives with higher cardiac index and serum Na:K ratio.

Adult↗

PubMed1988

Effect of mild aerobic exercise on lipid and apolipoprotein levels in patients with essential hypertension.

The effects of supervised mild aerobic exercise at the work load of the blood lactate threshold for 10 weeks on serum lipids and apolipoproteins were studied in 24 patients with essential hypertension. Significant reduction in both systolic and diastolic blood pressure and increased maximal oxygen uptake were observed in both men and women. The high density lipoprotein cholesterol increased significantly following mild aerobic exercise in women. Apolipoprotein A-II was significantly elevated at the 4th week in women. No significant differences in total cholesterol, triglyceride, low density lipoprotein cholesterol, apolipoproteins A-I, C-II, C-III, B and E were observed in either men or women following an exercise program. These data demonstrate the different effect of mild aerobic exercise therapy on high density lipoprotein in hypertensive men and women.

Adult↗

PubMed1987

Antihypertensive and volume-depleting effects of mild exercise on essential hypertension.

After a general clinical observation period of over 4 weeks, 20 essential hypertensive subjects (Japanese) were randomly divided into two groups. One group (n = 10; 4 men and 6 women; 51.4 +/- 2.8 years of age) agreed to physical training using bicycle ergometer exercise with the intensity at blood lactate threshold for 60 minutes three times a week for 10 weeks, while the other group (n = 10; 4 men and 6 women; 51.0 +/- 2.9 years of age) did no particular physical training and was followed once a week as the control. Changes in blood pressure, hemodynamics, and humoral factors of the exercised group were compared with values in the controls. The following significant changes were found only in the exercised group. Blood pressure was significantly (p less than 0.01) reduced. Whole blood and plasma volume indices were significantly reduced (p less than 0.05, p less than 0.01, respectively). The change in ratio of serum sodium to potassium positively correlated with the change in systolic blood pressure (r = 0.76, p less than 0.02). Plasma norepinephrine concentrations both at rest and at the workload of blood lactate threshold during graded exercise tests were significantly reduced (p less than 0.05, p less than 0.02 respectively) after 10 weeks of exercise training. The change in the resting level of plasma norepinephrine positively correlated with that in the mean blood pressure. No such changes were observed in the control group. In both groups, body weight and urinary sodium excretion showed no statistically significant changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1987

Effect of mild aerobic exercise on serum lipids and apolipoproteins in patients with coronary artery disease.

The effects of mild aerobic exercise on serum lipids, apolipoproteins and lecithin-cholesterol acyltransferase (LCAT) activity were examined in 11 male patients with coronary artery disease and 4 healthy male controls. The mild aerobic exercise program involved exercise intensity at 50% of maximal oxygen uptake, as determined from the blood lactate threshold, for 60 min periods 3 times per week for 10 weeks. Following mild aerobic exercise, serum levels of high density lipoprotein cholesterol (HDL-C) were increased significantly from 50 +/- 7 mg/dl to 59 +/- 11 mg/dl (p less than 0.05) with a simultaneous increase in apolipoprotein A-I (apo A-I) in normal controls. The LCAT activity was significantly increased from 65 +/- 22 nmol/ml/hr to 99 +/- 30 nmol/ml/hr in normal controls (p less than 0.05). Furthermore, maximal oxygen uptake (VO2max) was significantly increased in normal controls. In contrast, no significant changes were found in HDL-C, apo A-I, apo B, VO2max and body weight in patients with coronary artery disease. There was significant correlation between the initial HDL-C level and the change in HDL-C level following the exercise program in the combined group of normal controls and patients with coronary artery disease.

Aerobiosis↗

PubMed1986

Effect of acute exercise on plasma immunoreactive-atrial natriuretic factor.

The effect of acute exercise on plasma immunoreactive-atrial natriuretic factor (IR-ANF) was studied in 5 healthy young males subjected to graded exercise on a bicycle ergometer at four different work intensities (approx. 30, 50, 70, and 90% VO2max respectively). Except for the final exercise period, which was continued until exhaustion, all the others were of 30 min duration. Venous blood samples were obtained in the last 2 min of each exercise period. The plasma IR-ANF response to exercise was similar to that of heart rate and systolic blood pressure in that mild exercise in the first stage (corresponding to approx. 30% VO2 max) caused a striking increase of plasma IR-ANF concentrations with a further augmentation in the next stages and a levelling off at exhaustion. Plasma arginine-vasopressin (AVP) and aldosterone (ALDO) rose significantly only in the last two stages, and the highest concentrations were observed at exhaustion. In conclusion, acute exercise stimulates ANF secretion in proportion to the intensity of exercise, while concomitant increases in plasma AVP and ALDO occur only when the work load exceeds the blood lactate (BLA) threshold.

Adult↗

PubMed1985

Saccharomyces cerevisiae strains sensitive to inorganic mercury. II. Effect of glucose.

Saccharomyces cerevisiae strains sensitive to inorganic mercury (Ono and Sakamoto 1985) did not grow well on the medium rich in glucose and poor in peptone. This growth inhibition, like growth inhibition caused by inorganic mercury, was relieved by exogenous tyrosine. Sugars such as fructose and mannose were as inhibitory as glucose, but glycerol was not at all. Galactose was inhibitory but not so much as glucose. A gal2 mutation (defective in galactose uptake) partly relieved growth inhibition caused by excess galactose. Moreover, it was found that some of revertants which gained ability to grow well in the presence of excess glucose were defective in the glucose uptake. From these observations, we conclude that growth inhibition of the inorganic mercury sensitive strains by excess sugar is a consequence of the catabolite regulation. In other words, the inorganic mercury sensitive strains are hyper-sensitive to the catabolite regulation due to the presence of the HGS2-1 allele.

Culture Media↗

PubMed1985

A case of hyperreninemic hypertension with unilateral hydronephrosis.

A patient with unilateral ureteral obstruction by urolithiasis at the ureteropelvic junction was accompanied by hypertension. Plasma renin activity (PRA) was high in peripheral veins and was significantly higher in the renal vein drained from the affected kidney than the contralateral. Infusion of angiotensin II antagonist or an oral administration of captopril, an angiotensin converting enzyme (ACE) inhibitor, resulted in a prompt drop of blood pressure. After pyelolithotomy was successfully performed, both the blood pressure and peripheral PRA completely normalized. It is suggested that the renin-angiotensin system might have played a major role in the mechanism of the accompanied hypertension. Hyperreninemia could have been caused by both renal ischemic vasoconstriction, which might be due to uretero-renal reflex, and increased synthesis of prostaglandins resulting from ureteropelvic obstruction.

1-Sarcosine-8-Isoleucine Angiotensin II↗

PubMed1985

Crystal structure of a left-handed RNA tetramer, r(C-br8G)2.

The crystal structure of the modified RNA tetramer, r(C-br8G-C-br8G), was determined by x-ray methods. The crystals are trigonal and belong to the space group P3212. There are three independent tetramers in the unit cell and each forms a left-handed duplex similar to Z-DNA regarding the orientations of the base moiety and the sugar puckerings in guanosine and cytidine. The effect of the additional bromine atom and 2'-hydroxy group on the stabilization of the Z-form structure are also described.

Crystallization↗

PubMed1977

[Clinical experience with S-6436 in patients with urinary tract infections (author's transl)].

Forty eight patients with urinary tract infections including a case of acute prostatitis were treated with S-6436 and the following results were obtained: 1. Thirty eight patients with acute cystitis resulted in 19 excellent, 15 good and 4 poor with effectiveness rate of 89.5%. 2. Ten patients with complicated urinary tract infections resulted in 1 excellent, 5 good and 4 poor with effectiveness rate of 60%. 3. Infecting organisms from 38 patients with acute cystitis were occupied by 28 strains of E. coli. The sensitivity rate of the infecting organisms to cephalexin was 96.4%. 4. In a few cases (6.25%) side effects of S-6436 were observed. 5. S-6436 will be one of the good first choice antibiotics for acute cystitis.

Acute Disease↗

PubMedDate not supplied

Expansion of human hepatocyte populations by a retroviral gene transfer of simian virus 40 large T antigen.

A hybrid artificial liver (HAL) could be used to treat acute liver failure or to serve as a temporary support until orthotopic liver transplantation is available. Primary human hepatocytes are ideal as a source of hepatic function in a HAL device. However, the worldwide shortage of human livers available for hepatocyte isolation severely limits this form of therapy. A possible alternative is to use a tightly regulated cell line that can be economically grown in culture to have differentiated liver function. In this work, human hepatocytes were immortalized with a retroviral vector SSR#69 expressing the genes of simian virus 40 large T antigen and herpes simplex virus-thymidine kinase. One of the resulting clones, NKNT-3 , showed the gene expression of differentiated liver function and were sensitive to the antiviral agent ganciclovir. When transplanted into the spleen of rats subjected to 90% hepatectomy, NKNT-3 cells prolonged the survival of 90% hepatectomized rats. The cells provide the advantages of unlimited availability, sterility, uniformity, and freedom from pathogens. This work represents a potential novel strategy for resolving the organ shortage that currently limits the use of primary human hepatocytes to develop a HAL.

Acute Kidney Injury↗