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Biomedical subjects

S Fukuchi

Publications and source records attributed to S Fukuchi.

At least 145 records · Page 8Linked to original sources
PubMed1986

Antihypertensive effect of a new calcium channel blocker, FK 235, in essential hypertension.

The antihypertensive effect of a new calcium channel blocker (FK 235) were evaluated in 10 patients with mild-to-moderate essential hypertension. The study consisted of 4 weeks of placebo and 12 weeks of the drug, 2 to 4 mg twice a day. Overall systolic and diastolic blood pressures (mean +/- SE) were reduced from 173 +/- 4 to 158 +/- 2 mm Hg (p less than 0.001) and from 97 +/- 2 to 89 +/- 1 mm Hg (p less than 0.001), respectively, with a dose of 5.6 +/- 0.7 mg/day. No relevant changes in heart rate, body weight, and plasma levels of renin activity and aldosterone concentration were observed. No side effects were encountered during the therapy. Our data indicate that the novel active calcium channel blocker can be used as a safe, effective and well tolerated antihypertensive for the treatment of essential hypertension.

Adult↗
PubMed1986

[Diagnosis of gastric carcinoma by electronic endoscope].

The TV-Endoscope (by Toshiba Machida) provides excellent resolution with about 100,000 pixels and superior endoscopic findings to that of fiberscope, even though there still remain some improvements to be expected on its manipulability in comparison with the panendoscope. We can observe minute surface structure of gastric mucosa such as gastric pits. The endoscopic diagnosis in the new age of the electronic endoscope will reach to the stage of differential diagnosis not only based on the gross appearance of the lesions but also on the minute surface structure ranging from the gastric area to the gastric pits. Moreover, the application of the image processing or image analysis taking advantage of characteristics of electronic endoscope will develop the new stage of endoscopic diagnosis.

Female↗
PubMed1985

[Evidence for the existence of inactive renin in the rat brain. Part II. Distribution of inactive renin in the brain of spontaneously hypertensive rats].

Inactive renin in the brain of spontaneously hypertensive rat was investigated. The results are as follows. Treatment with either trypsin or glandular kallikrein of the brain tissue extract 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 41,000 or 50,000 daltons, while that of the trypsin-activatable inactive renin was found to be 44,000 or 57,000 daltons on a column chromatography with Sephadex G-100. The contents of the active renin was the highest in the hypothalamus, followed by the striatum, thalamus, midbrain, medulla oblongata, cerebral cortex and cerebellum, while the contents of the trypsin-activatable inactive renin was the highest in the hypothalamus, followed by the striatum, thalamus, cerebellum, midbrain, cerebral cortex and medulla oblongata. These results suggest that inactive renin(s) exist in the brain of spontaneously hypertensive rat. It seems likely that the brain renin-angiotensin system is modulated by the conversion of inactive to active renin(s), which, in turn, plays at least in part a role in the blood pressure regulation through generation of angiotensin II in spontaneously hypertensive rats.

Animals↗
PubMed1985

Multiple forms of immunoreactive renin in human pituitary tissue.

Immunoreactive renin was demonstrated in pituitary tissues of postmortem human subjects with different diseases. The specific immunoreactive renin activity comprised the majority of the tissue renin-like activity (mean, 83%), indicating the absence of nonspecific actions of proteases such as cathepsin D. We used three pituitary specimens with high levels of the specific renin activity for further biochemical characterization of the enzyme. Small differences were found in the molecular mass (45 K, 42 K and 37 K), binding to concanavalin A-Sepharose, and isoelectric points (pI) (4.72, 4.78, 4.86, 5.06, 5.28 and 5.44). These results seem to be interpreted as evidence for the presence of specific renin in the human pituitary with microheterogeneity.

Chromatography, Affinity↗
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

[The effects of o,p'-DDD on adrenal steroidogenesis and hepatic steroid metabolism].

O,p'-DDD is used for the treatment of adrenocortical carcinoma and Cushing's disease. The inhibitory effect of this drug on the adrenal steroid biosynthesis has been described by many authors, but there are very few reports about the sites of action of this drug on adrenal steroid synthesis. This paper presents in vitro studies on adrenal steroidogenesis and hepatic steroid metabolism. The effects of o,p'-DDD on adrenal 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 11 beta-hydroxylase (11 beta-OHlase) and 18-hydroxylase (18-OHlase) were examined in vitro using mitochondrial and microsomal fractions prepared by standard centrifugation procedures from the homogenate of bovine adrenal cortices. The concentrations of o,p'-DDD inducing 50% inhibition of 3 beta-HSD, 11 beta-OHlase and 18-OHlase were 8 X 10(-6) M, 1 X 10(-5) M and 3 X 10(-6) M, respectively. This study clearly demonstrates the marked inhibitory effects of o,p'-DDD on 3 beta-HSD in vitro, which was not described previously. The inhibitory effects of o,p'-DDD on these 3 enzymes were diminished by an addition of 0.05 approximately 0.5 mM of cofactor (NADPH or NAD). The results indicate that o,p'-DDD may reduce NADPH or NAD utilization, resulting in the inhibition of steroidogenesis. The effects of o,p'-DDD on hepatic 5 beta-reductase were examined in vitro using rat liver homogenate. O,p'-DDD inhibits 5 beta-reductase, resulting in the decrease of conversion of cortisol to dihydrocortisol and tetrahydrocortisol at the concentration of 10(-3) M.

18-Hydroxycorticosterone↗
PubMed1985

Renin and angiotensin-converting enzyme in human neuroblastoma tissue.

High activity of renin was demonstrated in human neuroblastoma tissue. This activity was inhibited by specific antibody raised against human renal renin, indicating that it was not due to the nonspecific action of proteases. The specific activity of renin was 122.8 ng of angiotensin I generated mg of protein-1 h-1. It shared some biochemical features with well-known kidney renin, such as molecular weight, optimum pH, the presence of trypsin-activatable inactive renin, and glycoprotein nature. Furthermore, angiotensin-converting enzyme (ACE) activity (2.64 nmol mg of protein-1 min-1) was found in the tissue. This activity was inhibited by captopril, a specific ACE inhibitor, or by omission of chloride ion. These results suggest that true renin in addition to ACE exists in human neuroblastoma tissue.

Animals↗
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

Immunoreactive renin in human brain: distribution and properties.

Readily detectable levels of renin activity were demonstrated in the human brain. This activity was inhibited by specific antibody raised against human renal renin, indicating that it was not due to the nonspecific action of proteases such as cathepsin D. The pineal gland was found to be the richest source of renin followed by the pituitary, hypothalamus and hippocampus. The substantia nigra, caudate nucleus, putamen and thalamus contained moderately high concentrations of renin. The brain renins from pineal and pituitary glands shared some biochemical features with well-known kidney renin, such as molecular weight (46,000 daltons for pineal renin; 37,000-45,000 daltons for pituitary renin), optimum pH (6.0-7.0), the presence of trypsin activatable inactive renin, and a glycoprotein nature. However, the electrofocusing pattern of renin from pituitary tissue (pI = 4.43, 5.77) differed from that of plasma and kidney enzymes heretofore reported, a discrepancy which could be interpreted as evidence for the endogeneous synthesis of renin in the brain tissue. Furthermore, a high activity of immunoreactive renin was found in human neuroblastoma tissue. The biochemical characteristics of the neuroblastomal renin were generally similar to the known properties of kidney renin in many respects, providing evidence of the presence of the renin-angiotensin system within human neuronal cells.

Brain↗
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

Acute effects of the new oral angiotensin converting enzyme inhibitor 1-(D-3-acetylthio-2-methylpropanoyl)-L-prolyl-L-phenylalanine (Alacepril) in essential hypertension.

In 15 patients with mild-to-moderate essential hypertension a new orally active angiotensin converting enzyme inhibitor, 1-(D-3-acetylthio-2-methylpropanoyl)-L-prolyl-L-phenylalanine (Alacepril), was administered with a single oral dose of 50 mg to evaluate its antihypertensive effect. Following Alacepril plasma angiotensin converting enzyme (ACE) activity was inhibited by approximately 75% within 2 h. Plasma renin activity increased slightly whereas plasma levels of aldosterone decreased significantly. Blood pressure fell markedly not only in patients with high renin levels but also in those with low renin levels. Nevertheless, the magnitude of blood pressure reduction was correlated with the pre-treatment plasma renin values (r = -0.602, p less than 0.05 systolic, r = -0.667, p less than 0.01 diastolic). No relevant changes in pulse rate was observed. These findings demonstrate that in essential hypertension the novel orally active ACE inhibitor Alacepril exerts marked antihypertensive effect, which may offer a new effective approach to treatment of hypertension.

Administration, Oral↗
PubMed1985

Biochemical identification of renin in human pheochromocytoma.

A high activity of renin was demonstrated in human pheochromocytoma tissue. This activity was inhibited by specific antibody raised against human renal renin, indicating that it was not due to the nonspecific actions of proteases such as cathepsin D. The specific renin shared some biochemical features with well-known kidney renin, such as molecular weight (47,000 daltons), optimum pH (6.0), the presence of trypsin-activatable inactive renin, and glycoprotein nature. However, the isoelectrofocusing pattern of renin from the pheochromocytoma differed from that of kidney and plasma renins hitherto reported, a discrepancy which could be interpreted as evidence for endogenous synthesis of the enzyme. Furthermore, angiotensin converting enzyme activity was found in the tissue. Since pheochromocytoma is considered to be of neural crest origin, these results provide biochemical and immunological evidence for the presence of the renin-angiotensin cycle within human neuronal cells.

Adolescent↗