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Biomedical subjects

M Gotoh

Publications and source records attributed to M Gotoh.

At least 469 records · Page 26Linked to original sources
PubMed1985

[Clinical significance of serum angiotensin I-converting enzyme in essential hypertension].

The present study was designed to clarify the role of serum angiotensin I-converting enzyme (ACE) in the occurrence and maintenance of hypertension in essential hypertension (EH). For this purpose, following experiments were carried out: 1) Correlations between serum ACE activity and renin activity (PRA), aldosterone concentration (PAC) and bradykinin concentration (PBC) in plasma, and blood pressure (BP) as well as serum creatinine levels. 2) Circadian rhythm of serum ACE activity. and 3) Effect of furosemide, upright posture, both furosemide and upright posture, propranolol, indomethacin, 9 alpha-fluorocortisol or angiotensin II (A-II) on the serum ACE activity, PRA, PAC and circulating plasma volume (CPV). The following results were obtained: The serum ACE activity was 30.2 +/- 5.0 U/ml (means +/- SD) in EH as a group, which was significantly higher than that (27.3 +/- 3.9 U/ml) in age matched normotensive subjects (NT) (p less than 0.001). While there was no significant difference in the enzyme activity between low-renin EH (LREH) and NT, a significant difference was found between normal- (NREH) or high-renin EH (NREH) and NT (p less than 0.05 for NREH, p less than 0.01 for HREH). A negative correlation was observed between enzyme activity and age in EH (r = -0.221, 0.05 less than p less than 0.10) as well as in NT (r = -0.306, p less than 0.05). No significant relationships were observed between enzyme activity and BP in either EH or NT. There was a significant positive correlation between enzyme activity and PRA in NT. (r = 0.501, p less than 0.001), NREH (r = 0.658, p less than 0.001) and HREH (r = 0.695, p less than 0.001). However, no significant relationship was found between them in LREH. The enzyme activity was significantly correlated to PAC in NT (r = 0.368, p less than 0.01), NREH (r = 0.567, p less than 0.001) and HREH (r = 0.529, p less than 0.01), but not in LREH. Although no significant correlation was observed between enzyme activity and PBC in NT, NREH and HREH, a significant relationship was found in LREH (r = -0.460, 0.05 less than p less than 0.10). The enzyme activity was not related to serum creatinine levels in EH as well as in NT. In NT, the serum levels of ACE activity reached a maximum values at 6:00 a.m. or 9:00 a.m., and gradually decreased between 6:00 p.m. and 3:00 a.m. An almost similar circadian rhythm of enzyme activity was found in EH.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

[Biochemical properties of renin in human pituitary tissue].

The biochemical properties of renin, extracted from human pituitary specimens obtained at autopsy, were studied using a specific antirenin antibody raised against human kidney renin. The following results were obtained. The molecular weight of pituitary renin was estimated to be about 37,000 daltons by gel filtration through Sephadex G-100. The optimum pH of pituitary renin was between 6.0 approximately 7.0, while that of a renin-like substance which did not react with the antirenin antibody had an acidic pH of 4.0, with a pH comparable to that of the cathepsin D-like enzyme in the pituitary tissue. The presence of two different isoelectric-point species of pituitary renin was revealed by isoelectric focusing, one with a point of pH 4.47 and the other with that of pH 5.77. The Km value of pituitary renin was 37.9 microM for synthetic human renin substrate. Affinity chromatography of the pituitary renin on a Concanavalin-Sepharose column showed that most (87.4%) of the pituitary renin did not contain glycoprotein residues. Treatment with either trypsin or glandular kallikrein increased the renin activity, indicating the presence of an inactive form of renin in the pituitary tissue. From these findings, it is concluded that specific renin exists in human pituitary tissue. It seems likely that the pituitary renin is of local origin rather than contamination of the circulating enzyme.

Chromatography, Affinity↗
PubMed1985

[The acute effects of the new angiotensin I-converting enzyme inhibitor, enalapril maleate, on blood pressure, plasma renin, aldosterone and kinins in hypertensive patients].

The acute antihypertensive effect of a new long-acting oral angiotensin I-converting enzyme (ACE) inhibitor, enalapril maleate, was assessed in 20 hypertensive patients, of whom 14 had essential hypertension, 4 had renovascular hypertension, one had hypertension associated with chronic renal failure, and one had primary aldosteronism. Enalapril maleate significantly lowered the blood pressure in either low-renin or normal- and high-renin hypertensives. There was a significant correlation for all patients as a group between the pretreatment levels of serum ACE activity and the reduction in mean blood pressure (r = -0.454, p less than 0.05, n = 20) 2 h after drug administration. The serum ACE activity decreased maximally 3 to 4 hours after drug administration and did not return to baseline levels within 24 h. There was a significant correlation between the reduction in mean blood pressure and changes in ACE activity 90 min and 2 h after drug administration, respectively, for all patients as a group (r = 0.495, p less than 0.05, n = 20, at 90 min; r = 0.508, p less than 0.05, n = 20, at 2 h). The plasma renin activity (PRA) significantly increased in normal- and high-renin hypertensives but not in low-renin hypertensives. There was a close correlation between the reduction in mean blood pressure and the PRA 8 h after drug administration in normal- and high-renin patients (r = -0.623, p less than 0.05, n = 13), while no such relationship was observed in low-renin patients. The plasma aldosterone concentration (PAC) significantly decreased within 3 h, the lowest values occurring at 8 h after drug administration, and it returned to baseline levels within 24 h in all patients. No relationship was found between the reduction in mean blood pressure and changes in PAC after drug administration in either low-renin or normal- and high-renin hypertensives. The plasma bradykinin concentration (PBC) increased within 1 h, the highest values occurring at 3 h after drug administration, and returned to baseline levels within 24 h in low-renin hypertensives, while the PBC was significantly increased at 4 h and had not returned to baseline levels within 24 h in normal- and high-renin hypertensives. There was a significant correlation between percentage changes in mean blood pressure and those in PBC 90 min after drug administration in normal- and high-renin hypertensives (r = -0.556, p less than 0.05, n = 13), while no relationship was observed between them in low-renin hypertensives.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1985

True renin in human pituitary tissue.

Readily detectable levels of renin activity were demonstrated in human pituitary tissues. This activity was inhibited by specific antibody raised against human renal renin, indicating that it was not due to the nonspecific action of proteases. It shared some biochemical features with well-known kidney renin, such as molecular weight, optimum pH, and the presence of trypsin-activatable inactive renin. These results suggest that true renin exists in human pituitary tissue.

Adult↗
PubMed1985

Central hyperglycaemic effect of adrenaline and carbachol.

The effect of chemical stimulation of the brain on glucoregulation was studied in anaesthetized rats. Adrenaline, noradrenaline, acetylcholine, dopamine and carbachol (5 X 10(-8) mol/microliter saline) were injected directly into the third cerebral ventricle and changes in hepatic venous plasma glucose, immunoreactive glucagon and insulin concentrations were studied. The injection of adrenaline and carbachol into the third cerebral ventricle resulted in a marked hyperglycaemia associated with increased immunoreactive glucagon. Adrenaline-induced hyperglycaemia was not affected by bilateral adrenalectomy, while carbachol-induced hyperglycaemia was completely inhibited by adrenalectomy. The injection of somatostatin (1 X 10(-9) mol) with adrenaline into the third cerebral ventricle did not influence adrenaline-induced hyperglycaemia, while carbachol-induced hyperglycaemia was inhibited by co-administration with somatostatin. These results suggest that adrenergic and cholinergic neurons in the central nervous system may increase hepatic glucose output by different mechanism.

Acetylcholine↗
PubMed1985

Evidence for existence of inactive arterial renin-like enzyme in the rat.

Inactive renin-like enzyme(s) in the arterial wall of the rat are converted to active renin-like enzyme in vitro by either "acid activation" (dialysis to pH 3.3 followed by dialysis to pH 7.4) or "protease-induced activation" (trypsin, alpha-chymotrypsin and glandular kallikrein). The molecular weights of the inactive renin-like enzyme(s) before trypsin activation were estimated to be about 68,000, 44,000, 36,000 and 30,000 by column chromatography. These findings may offer a new aspect for the role of the arterial renin-angiotensin system in the local control of vascular tone by interconversion of the inactive to the active renin-like enzymes in the arterial wall.

Animals↗
PubMed1985

[Clinical application of a new fibrin adhesive (Tisseel) in urologic surgery].

Our experience with the use of a new biological tissue adhesive (Tisseel) consisting of highly concentrated human fibrinogen, thrombin and factor XIII in urologic surgery is reported. In 21 operations (18 patients), Tisseel was used for the purpose of tissue adhesion and reduction of sutures of the renal parenchymal wound in nephrolithotomy, water tight sealing in suture part of expanded pyelolithtomy and vasovasostomy, and local hemostasis of oozing in prostatectomized fossa. Tisseel was not responsible for the two unsuccessful trials; and, undesirable complications due to this adhesive were few. Our results revealed that this new fibrin adhesive will be useful for urologic surgery.

Adult↗
PubMed1985

[A histological study on osteosarcoma. Part II: The mode of local extension of osteosarcoma].

The survival rate of patient with osteosarcoma has been increasing, owing to the development of adjuvant chemotherapy. Recently, the limb saving procedure in osteosarcoma has been attempted in many countries. Although we need knowledge about the mode of local extension of osteosarcoma in the planning of this surgery, there are few reports concerning the matter. The purpose of this paper is to make clear, morphologically, how tumor tissue extends across the epiphyseal plate, periosteum and bone marrow. The materials were 26 amputated extremities of osteosarcoma which had not received any chemotherapy or radiotherapy. Paraffin embedded macrosections were prepared and stained with HE and Masson stain. When epiphyseal plate was open or closing, 13 out of 14 cases (93%) showed transphyseal extension of tumor. Tumor extension along the vessels at the center of the plate and the epiphyseal artery was most common. Transmedullary extension showed three different types, infiltrative type (18 cases), lobular type (5 cases), and "skip" type (one case). None had capsule or pseudocapsule surrounding the tumor. As to the relationship between periosteal reaction and tumor involvement of cortex or medulla, periosteal reaction was located more proximally than cortical or medullary involvement in some cases. In other cases, however, cortical or medullary involvement was located more proximally than periosteal reaction. The gaps between the tips of the periosteal reaction and cortical or medullary involvement ranged from 0.5 to 1.5 cm. In the transperiosteal extension, it was confirmed that tumor cells had invaded the periosteum along the vessels penetrating the periosteum.

Adolescent↗
PubMed1984

[Evidence for the existence of inactive brain renin in the rat. Part I. Activating mechanisms and regional distribution of inactive renin in the brain of normotensive rats].

Inactive renin in rat brains was investigated according to the following experiments. Treatment with either trypsin or glandular kallikrein of the brain tissue caused a rapid and apparent increase in the renin activity at either 0 or 27 degrees C. The molecular weight of the active renin was estimated to be 40,000 daltons, while that of the trypsin-activatable inactive renin was found to be 48,000 or 61,000 daltons on a column chromatography with Sephadex G-100. The contents of the active renin was the highest in the hypothalamus, followed by striatum, thalamus, midbrain, cerebral cortex, medulla oblongata and cerebellum, while the contents of the trypsin-activatable inactive renin was the highest in the hypothalamus, followed by striatum, thalamus, midbrain, cerebellum, cerebral cortex and medulla oblongata. These results suggest that inactive renin(s) exist in the brain. It seems likely that the brain renin-angiotensin system is modulated by the conversion of inactive to active renin(s).

Animals↗
PubMed1984

[Serum angiotensin I converting enzyme activity in patients with hyperthyroidism and hypothyroidism: relation to renin and aldosterone].

In order to ascertain whether angiotensin I converting enzyme (ACE) activity might be regulated by thyroid hormone, serum ACE activity was measured in a variety of thyroid states, including hyperthyroid and hypothyroid subjects. In addition, the correlation of serum ACE activity to plasma renin activity (PRA) and plasma aldosterone concentration (PAC) was evaluated in these patients. In hyperthyroid patients, the mean (+/- SD) serum ACE activity was 32.7 +/- 6.7 U/ml (n = 30), which was significantly higher than that in hypothyroid patients (20.4 +/- 4.3 U/ml, n = 7, p less than 0.001) and in normal subjects (22.5 +/- 3.4 U/ml, n = 51, p less than 0.001). No significant difference in serum ACE activity was found between the hypothyroid patients and normal subjects. There was a significant positive correlation between serum ACE activity and PRA (r = 0.524, n = 30, p less than 0.01) and also between serum ACE activity and PAC (r = 0.473, n = 30, p less than 0.01) in the patients with hyperthyroidism. By contrast, no significant relationship was observed between serum ACE activity and thyroid hormones (r = 0.115, for T3; r = 0.143, for T4) in hyperthyroid patients. Treatment with furosemide (1 mg/kg i.v.) and upright posture (2h) significantly increased PRA, PAC and serum ACE activity in both hyperthyroid patients and normal subjects, but not in hypothyroid patients. There was a significant positive correlation between changes in serum ACE activity and in PRA (r = 0.418, n = 23, p less than 0.05) in response to the treatment in hyperthyroid patients, while no significant relationship was observed between them in either hypothyroid patients (r = 0.216, n = 6, p less than 0.10) or normal subjects (r = 0.620, n = 10, 0.05 less than p less than 0.01). In one patient with hyperthyroidism, administration of propranolol decreased PRA from 3.4 to 2.3 ng/ml/h, corresponding to an apparent decrease in serum ACE activity from 38.7 to 29.6 U/ml. From these results, it is suggested that serum ACE activity in the hyperthyroid state is modulated by the renin-angiotensin system rather than by thyroid hormone.

Adult↗
PubMed1984

[Evidence for the existence of inactive arterial renin in the rat].

Inactive renin in rat arterial walls was investigated according to the following experiments. Dialysis at pH 7.4 following dialysis at pH 3.3 of the arterial tissue resulted in a significant rise of renin activity, from a control value of 0.41 +/- 0.07 to 0.62 +/- 0.06 ng/ml/h (p less than 0.01). Treatment with trypsin of the arterial tissue caused a rapid and apparent increase in the renin activity at either 0 or 27 degrees C. The molecular weight of the active renin was estimated to be 32,000 or 39,000, while that of the inactive renin was found to be 36,000 or 44,000 on Sephadex G-100 gel filtration. The contents of the inactive renin varied with different segments of arterial wall. The ratio of inactive renin to total renin was the lowest in renal artery wall (0.32), while there was no significant difference in the ratio in other arterial walls (abdominal aorta, 0.87; thoracic aorta, 0.93; carotid artery, 0.96; mesenteric artery, 0.89; pulmonary artery, 0.92). These findings suggest that conversion of inactive renin into active renin can occur in arterial tissue, which, in turn, plays an important role in the local control of vascular tone. It seems that inactive renin found in the arterial wall is of local origin.

Animals↗
PubMed1984

[The effects of the angiotensin I-converting enzyme inhibitor, captopril, on serum lipoperoxides level and the renin-angiotensin-aldosterone and kallikrein-kinin systems in hypertensive patients].

In order to evaluate the effect of the angiotensin I-converting enzyme inhibitor, captopril, on lipid metabolism, we measured serum lipoperoxides concentration ( LPX ) as well as plasma levels of renin activity (PRA), aldosterone (PAC) and bradykinin ( PBK ) before and after captopril administration in 15 hypertensive patients. Captopril significantly lowered the LPX (p less than 0.05 by repeated measures ANOVA) from the control value of 3.25 +/- 1.16 (mean +/- S.D.) to 2.92 +/- 0.94, 2.83 +/- 1.10, and 2.89 +/- 1.31 nmol/ml 30, 60, and 120 min after the administration, respectively. A significant reduction of blood pressure (p less than 0.0001) and PAC (p less than 0.01) was observed following captopril administration, while PBK increased significantly (p less than 0.001) from a baseline level of 10.85 +/- 4.07 to 13.95 +/- 5.29, 16.25 +/- 6.85, and 15.71 +/- 7.65 pg/ml 30, 60, and 120 min after captopril administration, respectively. There was no significant correlation between changes in serum LPX and in mean blood pressure, PRA and PAC, though a significant inverse relationship was found between changes in serum LPX and in PBK 120 min after the administration (r = -0.576, p less than 0.05, n = 13). Although the mechanisms by which serum LPX is decreased by captopril are not clear, it is suggested from the results that captopril is a beneficial antihypertensive agent for preventing LPX -induced atherosclerosis in hypertensive patients.

Adult↗
PubMed1984

Leydig cell hyperplasia in cryptorchid patients: quantitative evaluation of Leydig cells in undescended and contralateral scrotal testes.

Leydig cell number was evaluated quantitatively in testicular biopsies from post-pubertal cryptorchid patients and normal controls. For this quantitative evaluation we used the following method. This is based on the determination of the total number of Leydig cells, Leydig cell clusters and seminiferous tubules in the entire histologic sections of each biopsy and the determination of the following indices; mean Leydig cells per tubule, mean Leydig cell clusters per tubule and mean Leydig cells per cluster. In addition, the numbers of Sertoli cells were counted, and Leydig-Sertoli cell ratio was also determined. These indices were correlated with each other. All indices were significantly elevated not only in undescended but in contralateral scrotal testes of the cryptorchid patients in comparison to those in normal controls. Between undescended and descended scrotal testes of the same individual patients, those indices were significantly higher in the descended scrotal testes than in the undescended ones. Thus, Leydig cell hyperplasia was noted in the testes of post-pubertal cryptorchid patients, and was more prominent in the contralateral scrotal testes than in the undescended ones.

Adolescent↗
PubMed1984

The effects of streptozotocin diabetes on tissue specific lipase activities in the rat.

Fasting in normal rats produced a fall in hepatic triglyceride lipase (H-TGL) activity as well as lipoprotein lipase (LPL) activities of adipose tissue and psoas minor muscle. On the other hand, LPL activities of heart and diaphragm were not decreased by fasting; the former, in fact, was increased significantly. Changes in tissue specific lipase activity caused by withdrawal of insulin from insulin-treated diabetic animals paralleled in direction the changes induced by starvation of normal rats. Furthermore, it was shown in the present paper that the tissue specific lipase activity of diabetic rats became stuck in the starve phase of the starve-feed cycle regardless of dietary intake. The changes of the tissue specific lipase activities, especially of liver, adipose tissue and heart, appeared to coincide with those of plasma insulin levels. These results strongly suggest that the tissue specific lipase system is under hormonal regulation by insulin. Streptozotocin diabetes produced hypertriglyceridemia. The possible mechanism of the hypertriglyceridemia in diabetic animals was discussed in connection with the role of the tissue specific lipase system in the serum triglyceride metabolism.

Adipose Tissue↗