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Biomedical subjects

E Gotoh

Publications and source records attributed to E Gotoh.

At least 73 records · Page 4Linked to original sources

Glucose and lipid metabolism during long-term lisinopril therapy in hypertensive patients.

The effects of long-term lisinopril therapy on glucose tolerance and serum lipid profiles were investigated prospectively in 30 hypertensive patients: 15 with normal glucose tolerance and the remaining 15 with glucose intolerance. The levels of plasma glucose, serum lipids, and plasma glycosylated hemoglobin A1c were determined before and during long-term (6 months) therapy with lisinopril. A 75 g oral glucose tolerance test was performed before and during long-term lisinopril therapy. Lisinopril produced significant falls in both systolic and diastolic blood pressure in both patient groups during the long-term therapy. Neither fasting nor post-glucose-load venous plasma glucose levels were altered in either group of patients, and no patients with normal glucose tolerance developed diabetes mellitus during the study. There was no significant change in the insulinogenic index (delta IRI/delta BS at 30 min post-glucose load) in both patient groups. No significant changes in fasting levels of serum cholesterol, triglycerides, and HDL-cholesterol were observed in either group during long-term lisinopril therapy. Long-term lisinopril therapy does not compromise glucose or lipid metabolism in hypertensive patients. Lisinopril may have an advantage as an antihypertensive agent that can be given to hypertensive patients without concern that it might alter their serum lipid concentrations or impair glucose tolerance.

Adult↗

Antihypertensive effects and pharmacokinetics of single and consecutive doses of cilazapril in hypertensive patients with normal or impaired renal function.

1. A 1.25 mg dose of cilazapril, a new angiotensin-converting enzyme (ACE) inhibitor, was administered orally to two groups of hypertensive patients, five with normal renal function (NRF) and seven with impaired renal function (IRF), once daily for 5 or 8 consecutive days. Blood pressure, heart rate and serum ACE activity were measured up to 24 h following the initial and the last dose. Plasma level profiles of cilazapril and its active diacid were also evaluated on the first and the last day of treatment. 2. Cilazapril induced significant falls in both systolic and diastolic blood pressures without increasing heart rate. The antihypertensive effect was evident within 1 h after drug administration and was sustained for up to 24 h, particularly after consecutive dosing. 3. Serum ACE activity was markedly suppressed over 24 h. The recovery of ACE activity was delayed in the IRF group when compared with the NRF group. 4. Plasma concentrations of the active diacid in the IRF group were higher than in the NRF group with significant differences in the peak concentrations and area under the plasma concentration-time curve (AUC). The plasma concentration profile for the parent drug was similar for both the NRF and IRF groups. 5. A significant inverse correlation was found between the creatinine clearance and the AUC for the diacid. 6. Cilazapril is a potent ACE inhibitor with a prolonged duration of antihypertensive effect and is a useful agent for controlling blood pressure in hypertensives either with NRF or IRF. In patients with severe renal impairment the dose of cilazapril should be reduced.

Angiotensin-Converting Enzyme Inhibitors↗

Lack of effect of vasopressin replacement on renin hypersecretion in Brattleboro rats.

To determine how the vasopressin deficiency in homozygous Brattleboro rats with diabetes insipidus produces increased renin secretion, homozygous and heterozygous Brattleboro rats were infused through subcutaneously implanted Alzet minipumps for 1 wk with a dose of arginine vasopressin that restored plasma vasopressin to normal in the homozygous animals. In the homozygous animals, plasma renin activity (PRA) and the PRA response to immobilization remained elevated compared with Long-Evans controls. Propranolol reduced PRA to normal and markedly reduced the PRA response to immobilization. PRA was normal in heterozygous Brattleboro rats. The data indicate that the increased renin secretion in homozygous rats is a result of increased sympathetic activity, and because circulating vasopressin does not cross the blood-brain barrier, it seems likely that the increased sympathetic activity is central in origin.

Animals↗

Lack of atrial natriuretic peptide receptors in human aldosteronoma.

The effect of synthetic alpha-human atrial natriuretic peptide (ANP) on aldosterone secretion was studied in human aldosterone producing adrenocortical adenoma obtained surgically from a patient with primary aldosteronism and in human apparently normal adjacent adrenal cortical tissues obtained from a patient with pheochromocytoma, in vitro. Apparently normal adrenal cortical tissue responded to ANP with the known inhibition of aldosterone secretion. In contrast, the aldosterone producing adenoma did not respond to ANP. When stimulated by either ACTH or angiotensin II, there is no inhibition by ANP in the adenoma tissue, whereas normal tissue was inhibited. Immunohistochemical examination utilizing an ANP-receptor antiserum demonstrated that there was no evidence of binding site in the cortical adenoma, in contrast, zona glomerulosa cells in the cortical tissues adjacent to either aldosterone producing adenoma or pheochromocytoma were densely stained. This apparent lack of ANP-receptors is an associated finding with the hypersecretion of aldosterone in the aldosterone producing adenoma.

Adenoma↗

Pharmacological evidence that the sympathetic nervous system mediates the increase in renin secretion produced by immobilization and head-up tilt in rats.

To determine the mechanism by which immobilization and head-up tilt under inactin anesthesia increase plasma renin activity (PRA), the effect of these stimuli on plasma levels of vasoactive intestinal polypeptide (VIP) were measured and the effect of the beta-adrenergic blocking drug, propranolol on the response of plasma renin activity determined. Increases in circulating VIP are known to stimulate secretion of renin. After 10 min of immobilization, plasma renin activity was increased and VIP in plasma was unchanged. After 30 min of tilting, plasma renin activity was also increased and VIP in plasma was unchanged. The increases in plasma renin activity were blocked by propranolol. Inactin anesthesia by itself increased plasma renin activity and this response was unaffected by propranolol and associated with a small decrease, rather than an increase in VIP in plasma. The results indicate that the responses of plasma renin activity to immobilization and head-up tilt are due to increased secretion of renin mediated by the sympathetic nervous system. On the other hand, the increase in secretion of renin produced by inactin anesthesia does not appear to be mediated by the sympathetic nervous system. There was no evidence that VIP was responsible for any of the increases.

Animals↗

Long-term captopril therapy with no effect on glucose metabolism in patients with essential hypertension.

The long-term antihypertensive response to captopril (25-50 mg/day) and 75g oral glucose tolerance (75g oGTT) following a 6-10 month period of captopril administration was evaluated in 20 patients with essential hypertension without persistent proteinuria. Eleven of these 20 patients exhibited impaired glucose tolerance (IGT), while the remaining nine patients had normal glucose tolerance (NGT). All patients tolerated long-term captopril therapy with no untoward effects. Six months' administration of captopril significantly decreased blood pressure in patients with NGT from 171 +/- 12/105 +/- 5 mm Hg (mean +/- SE) to 146 +/- 7/88 +/- 4 mm Hg. Also in patients with IGT, long-term captopril therapy decreased blood pressure from 165 +/- 3/97 +/- 2 to 143 +/- 5/86 +/- 2 mm Hg. No patient with NGT developed diabetes mellitus. Neither fasting nor post-glucose-load venous blood glucose deteriorated in any of the patients during the therapy. There were no significant changes in the insulinogenic index (delta IRI/delta BG at 30 minutes after glucose load) in both the patients with NGT and IGT. In patients with IGT, the concentration of glycosylated hemoglobin (Hb A1 and Hb A1c slightly but significantly decreased from 8.1 +/- 0.3 to 7.7 +/- 0.4% (P less than 0.05) and from 5.9 +/- 0.3 to 5.5 +/- 0.3% (P less than 0.01) after 6.2 +/- 1.4 months' captopril therapy. These results suggest that in addition to its antihypertensive effects, long-term captopril therapy does not compromise glucose metabolism in hypertensive patients.

Blood Pressure↗

Pharmacokinetics of single and consecutive doses of cilazapril and its depressor effects in hypertensive patients with renal dysfunction.

The pharmacokinetic properties and antihypertensive effects of cilazapril, a long-acting converting enzyme inhibitor, were investigated in seven hypertensive patients with renal failure. Cilazapril 1.25 mg was given orally once a day for 5 or 8 days. Cilazapril induced a significant decrease in both systolic and diastolic blood pressures, and its antihypertensive effect was still present 24 hours after administration. Serum-converting enzyme activity was markedly suppressed for at least 24 hours. No significant differences were noted in plasma peak level and the area under the curve between the first and last days of treatment. These results suggest that cilazapril has a long-lasting effect and is a useful antihypertensive agent in controlling blood pressure in hypertensive patients with renal failure.

Blood Pressure↗

Pharmacokinetics of single and consecutive doses of cilazapril and its depressor effects in patients with essential hypertension.

The pharmacokinetic properties and antihypertensive effects of cilazapril, a long-acting angiotensin-converting enzyme (ACE) inhibitor, were investigated in five patients with mild to moderate essential hypertension (mean age 57 years, mean serum creatinine 1.2 mg/dL, mean glomerular filtration rate 69 mL/min/1.73m2, mean blood pressure 158/94 mm Hg). All patients were hospitalized and placed on a constant sodium diet (7 g of NaCl/day) throughout the study. After an overnight fast, a 1.25-mg dose of cilazapril was given orally once a day for 5 or 8 days. On the first and last days of treatment, blood samples were taken and blood pressure was measured. All patients tolerated cilazapril with no untoward effects. Cilazapril induced a significant decrease in both systolic and diastolic blood pressure, and its antihypertensive effect was still present 24 hours after administration. Serum ACE activity was markedly suppressed for at least 24 hours. The peak plasma concentrations (Cmax) of cilazapril and its diacid were 117 and 24.6 ng/mL on the first treatment day, and 144 and 31.1 ng/mL on the last day. The area under the plasma concentration time curve (AUC) of cilazapril and its diacid were 408 and 227 ng.h/mL on the first day, and 501 and 305 ng.h/mL on the last day. In looking at the data gathered on the first and last treatment days, no significant differences were noted in Cmax and AUC values. These results suggest that cilazapril has a long-lasting effect and is a useful antihypertensive agent in controlling blood pressure in patients with mild to moderate essential hypertension.

Angiotensin II↗

Angiotensin II inhibits baroreflex control of muscle sympathetic nerve activity and the heart rate in patients with essential hypertension.

This study examined the effects of angiotensin II (Ang II) on blood pressure, heart rate and muscle sympathetic nerve activity in patients with essential hypertension and normotensive subjects. Muscle sympathetic nerve activity was measured by a microneurographic method. Graded doses of phenylephrine (0.5 and 1.0 g/kg per min) or Ang II (5, 10 and 20 ng/kg per min) were intravenously infused into supine subjects for 10 min at 30-min intervals. Although the pressor responses to Ang II and phenylephrine were enhanced in the hypertensives compared with the normotensives (both P less than 0.05), the reduction in muscle sympathetic nerve activity during infusion of phenylephrine and Ang II and the reduction in the heart rate during infusion of phenylephrine were significantly smaller in the hypertensives than in the normotensives. The decrease in the heart rate in response to Ang II was not significant in either group. Furthermore, in the two groups, the decreases in muscle sympathetic nerve activity and the heart rate were significantly smaller during infusion of Ang II than during infusion of phenylephrine. These results suggest that angiotensin II impairs the baroreflex function in patients with essential hypertension and in normotensive subjects, and that the blunted response of sympathetic nerve activity and the heart rate observed in the hypertensives may underlie the maintenance of high blood pressure.

Angiotensin II↗

Complete nucleotide sequence of human vasoactive intestinal peptide/PHM-27 gene and its inducible promoter.

We have previously shown that the VIP precursor contains a novel PHI-27-like peptide, PHM-27, and that the synthesis of the prepro-VIP/PHM-27 mRNA is induced with cAMP and TPA in human neuroblastoma cells. In this study, we have determined the complete nucleotide sequence of the human VIP/PHM-27 gene. The gene spans 8,837 bp and consists of seven exons and six introns. Exon I of 165 bp consists of the 5' untranslated region of the gene, exon II of 117 bp encodes the signal peptide of prepro-VIP/PHM-27, exon III of 123 bp encodes the amino-terminal region, exon IV of 105 bp encodes PHM-27, exon V of 132 bp encodes VIP, exon VI of 89 bp contains the termination codon of the prepro-VIP/PHM-27 mRNA, and exon VII of 724 bp consists of the 3' untranslated region of the gene. VIP and its structurally related peptide, PHM-27, were encoded in different exons V and IV, and the sequences around the splice junctions between these exons and their adjacent introns were highly conserved, suggesting that the VIP-encoding and PHM-27-encoding exons have been duplicated from an ancestral exon over a broad area containing its adjacent introns. We also determined the 1,929-bp sequence of the 5' flanking region of the human VIP/PHM-27 gene and found that four TATA-box sequences were present at 28 bp, 145 bp, 772 bp, and 900 bp upstream of the cap site. Primer extension, exon mapping, and mung bean nuclease mapping analyses revealed that only the TATA-box sequence 28 bp upstream of the cap site was the promoter that is inducible by cAMP and TPA in the human neuroblastoma cells. An 18-bp sequence 52 bp upstream from the TATA-box sequence was suggested to be a cAMP/phorbol esters-responsive element of the human VIP/PHM-27 gene.

Base Sequence↗

Relation of the ventromedial nuclei of the hypothalamus to the regulation of renin secretion.

During an investigation of the role of the mediobasal hypothalamus in the regulation of renin secretion from the kidneys, we found that lesions of the ventromedial nuclei prevented the increase in plasma renin activity produced by p-chloroamphetamine. In the present study, we tested the effects of bilateral electrolytic lesions of the ventromedial nuclei on the increase in plasma renin activity produced in sham-operated rats by immobilization, head-up tilt under inactin anesthesia, and a low-sodium diet. Ventromedial lesions reduced or abolished the plasma renin activity increase to all three stimuli without any change in plasma angiotensinogen. The plasma renin concentration responses to immobilization and a low-sodium diet were also reduced. All these stimuli probably exert their effect by way of the sympathetic nervous system. The data support the hypothesis that the ventromedial nuclei or neural fibers passing through them are important in the renin response to diverse stimuli that act by way of sympathetic discharge.

Angiotensinogen↗

Antihypertensive effects and pharmacokinetics of single and consecutive doses of cilazapril in hypertensive patients with normal and impaired renal function.

The antihypertensive effects and pharmacokinetic properties of cilazapril, a long-acting angiotensin-converting enzyme (ACE) inhibitor, were investigated in hypertensive patients with normal renal function (NRF; n = 5) and those with impaired renal function (IRF; n = 7). A 1.25-mg dose of cilazapril was administered orally once a day for 5 or 8 days. Measurement of blood pressure and sampling of blood specimens were done on the first and last days of treatment. Cilazapril induced significant falls in systolic and diastolic blood pressures as early as 1 h after administration. The antihypertensive effects were still present at 24 h postdose. Serum ACE activity was markedly suppressed over 24 h, with the enzyme inhibition greater in the IRF group. Plasma levels of the active diacid in the IRF group were higher than those in the NRF group, with significant differences in the peak levels and areas under the curve (AUC). A significant inverse correlation was found between the creatinine clearance and the AUC for the diacid. Cilazapril was well tolerated by all the patients, and no adverse reactions were observed. These results suggest that cilazapril has a long-lasting action and that it is a useful antihypertensive agent for controlling blood pressure in patients with either NRF or IRF.

Administration, Oral↗

Chromosomal assignment of human VIP/PHM-27 gene to 6q26----q27 region by spot blot hybridization and in situ hybridization.

We determined the chromosomal location of the human VIP/PHM-27 gene in two different ways. First, we performed chromosome sorting with a cell sorter. Sufficient numbers of chromosomes for sorting were obtained by cultivating peripheral blood lymphocytes with interleukin-2. Spot blot hybridization of a molecularly cloned fragment of the gene to the sorted chromosomes revealed that this gene is located on chromosome 6. To define the location more precisely, in situ hybridization of the same fragment to the metaphase spreads was then performed, and human VIP/PHM-27 gene was assigned to a region near the terminus of the long arm of chromosome 6 (q26----q27).

Chromosomes, Human, Pair 6↗

Role of brain serotonergic pathways and hypothalamus in regulation of renin secretion.

To investigate the role of brain serotonergic neurons in the regulation of renin secretion, we measured changes in plasma renin activity (PRA), and, in some instances, plasma renin concentration (PRC), plasma angiotensinogen, and plasma adrenocorticotropic hormone (ACTH) in rats with lesions of the dorsal raphe nucleus and lesions of the paraventricular nuclei, dorsomedial nuclei, and ventromedial nuclei of the hypothalamus. We also investigated the effects of p-chloroamphetamine (PCA), immobilization, head-up tilt, and a low-sodium diet in the rats with dorsal raphe, paraventricular, and dorsomedial lesions. Lesions of the dorsal raphe nucleus abolished the increase in PRA produced by PCA but had no effect on the increase produced by immobilization, head-up tilt, and a low-sodium diet. Paraventricular lesions, which abolish the increase in plasma ACTH produced by PCA, immobilization, and head-up tilt, decreased plasma angiotensinogen. The paraventricular lesions abolished the PRA and the PRC responses to PCA and the PRA but not PRC response to immobilization, head-up tilt, and a low-sodium diet. The ventromedial lesions abolished the PRA and PRC responses to PCA and did not reduce plasma angiotensinogen. The data suggest that paraventricular lesions depress angiotensinogen production by the liver and that the paraventricular and ventromedial nuclei are part of the pathway by which serotonergic discharges increase renin secretion. They also suggest that the serotonergic pathway does mediate the increases in renin secretion produced by immobilization, head-up tilt, and a low-sodium diet.

Animals↗

Effects of intranasal administration of atrial natriuretic hormone on spontaneously hypertensive rats.

The effects of the intranasal administration of synthetic alpha-human atrial natriuretic polypeptide (alpha-hANP) were investigated in 14 anesthetized spontaneously hypertensive rats (SHR; Okamoto-Aoki strain). They were given intranasally synthetic alpha-hANP in distilled water at doses of 10 micrograms/kg, 50 micrograms/kg and 100 micrograms/kg. Intranasal application of 200 microliter of distilled water as a control was also performed in 3 anesthetized SHR. Sixteen anesthetized SHR were examined for the effects of intravenous administration of alpha-hANP at doses of 4 micrograms/kg, 10 micrograms/kg, 20 micrograms/kg and 40 micrograms/kg. Urinary volume and the urinary excretion of sodium increased 2- to 3-fold during the 50 minutes following intranasal administration of a single dose of 50 micrograms/kg or 100 micrograms/kg, although neither the urinary volume nor the urinary excretion of sodium increased after intranasal administration of 10 micrograms/kg of alpha-hANP or 200 microliter of distilled water. There were no significant changes in arterial pressure or heart rate after the intranasal administration of synthetic alpha-hANP or distilled water. In contrast, arterial pressure was decreased and urinary volume and urinary excretion of sodium were increased, in a dose dependent manner, within 5 minutes after intravenous bolus-injection of alpha-hANP and returned to their baseline levels within 20 minutes. These results indicate that intranasal administration of synthetic alpha-hANP exerts its diuretic effect without concomitant changes in arterial pressure or heart rate in SHR.

Administration, Intranasal↗

Renal haemodynamics and comparative effects of captopril in patients with benign- or malignant-essential hypertension, or with chronic renal failure.

Effects of captopril on arterial pressure (AP) and renal function were investigated in patients with non-malignant "benign" or malignant phase essential hypertension (EH group), or with chronic renal failure (CRF group). After captopril administration, AP and renal vascular resistance (RVR) decreased significantly, and renal blood flow (RBF) and plasma renin activity (PRA) increased in both groups. Glomerular filtration rate (GFR) increased in the EH group, but was unchanged in CRF. Filtration fraction decreased in the malignant hypertension and CRF groups. Significant correlations were found between baseline PRA and baseline RVR, and the captopril-induced decrease in mean AP, decrease in RVR, increase in RBF, and increase in GFR in the EH group, while these associations were not observed in CRF. These results indicate that the high AP, RVR, suppressed RBF and GFR in the EH group were closely related to activity of the renin-angiotensin system, but not so the low RBF and GFR in CRF. Small doses of captopril may improve impaired renal function in EH, and may not cause deterioration in the CRF group.

Captopril↗