[Distribution and function of angiotensin II receptor subtypes--central nervous system].

AT1 receptors are predominant in the brain of monkeys and rabbits, while AT2 receptors are relatively abundant in the rat brain. In the human brain, all of the angiotensin II receptors in the forebrain, midbrain, pons, medulla and spinal cord are AT1 receptors, and AT2 receptors are found only in the cerebellum. Angiotensin II in the brain increases water and sodium intake, raises blood pressure, attenuates baro-reflex function, and increases vasopressin secretion.

Antisense inhibition of angiotensinogen attenuates vasopressin release in the paraventricular hypothalamic nucleus of spontaneously hypertensive rats.

It has been reported that intracerebroventricularly injected antisense oligonucleotide to angiotensinogen reduces arterial pressure in spontaneously hypertensive rats (SHR), but the mechanism and the sites of action remain unclear. In the present study, we examined whether injection of antisense oligonucleotide to angiotensinogen into the paraventricular hypothalamic nucleus (PVN) would influence arterial pressure and vasopressin release. For this purpose, 12-week-old male SHR were cannulated into the bilateral PVN.

Central adrenomedullin augments the baroreceptor reflex in conscious rabbits.

We examined the roles of central adrenomedullin, proadrenomedullin N-terminal 20 peptide (PAMP), and calcitonin gene-related peptide (CGRP) on the baroreceptor reflex in conscious rabbits. Intracerebroventricular injection of adrenomedullin (0.2 and 1 nmol/80 microL) elicited dose-related increases in arterial pressure and renal sympathetic nerve activity.

Syncope in a 65-year-old woman after nitrate ingestion.

A 65-year-old woman with angina pectoris presented with syncope after sublingual ingestion of isosorbide dinitrate (5 mg). Her response to a postural challenge test, without medication, was normal. In a postural challenge test after administration of isosorbide dinitrate (5 mg), blood pressure decreased from 120/67 to 65/35 mmHg, followed by syncope with a sudden decrease in pulse rate from 85 to 60 beats/min.

Central and peripheral mechanisms involved in hypertension induced by chronic inhibition of nitric oxide synthase in rats.

Objective: To study the possible central and peripheral mechanisms involved in hypertension induced by chronic inhibition of nitric oxide synthase.

Methods: We evaluated neurohormonal and renal responses of Wistar rats to chronic oral administration of 20 and 100 mg/kg per day NG-nitro-L-arginine methyl ester (L-NAME). Effects of intracerebroventricular and intravenous injections of NO donors (NOC-18 and FK-409) and an angiotensin II type 1 receptor antagonist CV-11974, and intravenous injection of alpha-adrenergic receptor antagonist phentolamine after chronic treatment with 100 mg/kg per day L-NAME were also studied.

Effect of interferon therapy on heart rate and sympathetic nervous system.

We investigated the hypothesis that interferon-induced hyperadrenergic state causes cardiovascular events. Thirteen patients with chronic hepatitis C who were scheduled to undergo interferon therapy were randomly selected for this study. Heart rate was monitored and urinary levels of catecholamines were measured before, on the 1st day, and after 1 week and 4 weeks of treatment.

Role of nitric oxide in the nucleus of the solitary tract of rats.

We have determined the role of nitric oxide (NO) in the nucleus of the solitary tract (NTS) of normotensive Wistar rats. The unilateral microinjection of Nomega-nitro-l-arginine methyl ester (10 nmol) to block the synthesis of NO into the NTS significantly decreased the arterial pressure, heart rate (HR) and renal sympathetic nerve activity (RSNA) (-19+/-2 mmHg, -23+/-5 beats/min, -30+/-2%, respectively). The microinjection of carboxy-2-phenyl-4,4,5, 5-tetramethylimidazoline-1-oxyl 3-oxide (Carboxy PTIO) (trapper of NO; 0.

Single L-type calcium channels in smooth muscle cells from resistance arteries of spontaneously hypertensive rats.

The amplitude of the whole-cell L-type Ca2+ channel current recorded from vascular smooth muscle cells is reportedly greater in spontaneously hypertensive rats (SHR) than in Wistar-Kyoto rats (WKY). However, no study has examined properties of single Ca2+ channels in arterial cells from these strains. To further test the hypothesis that activation of L-type Ca2+ channels in arterial smooth muscle cells would be enhanced in SHR, we recorded single Ca2+ channel currents in resistance mesenteric artery cells from SHR and WKY (8 to 9 weeks of age) using a cell-attached patch clamp technique.

Central nitric oxide attenuates the baroreceptor reflex in conscious rabbits.

We examined the role of central nitric oxide (NO) in the baroreceptor reflex in conscious rabbits. Intracerebroventricular infusion of 20 mumol of N omega-nitro-L-arginine methyl ester (L-NAME) to block central NO resulted in increases in arterial pressure, renal sympathetic nerve activity (RSNA), and plasma catecholamine levels, and the pressor response was suppressed by pretreatment with pentolinium (5 mg/kg i.v.

Enhanced depressor response to nitric oxide in the rostral ventrolateral medulla of spontaneously hypertensive rats.

Possible impairment of the L-arginine-nitric oxide (NO) pathway in the rostral ventrolateral medulla of adult spontaneously hypertensive rats (SHR) was investigated by microinjecting N(G)-nitro-L-arginine methyl ester (L-NAME), NOC 18 (an NO donor), or L-arginine. Unilateral injection of L-NAME (10 nmol/50 nL) into the rostral ventrolateral medulla significantly increased mean arterial pressure (MAP) in both SHR and Wistar-Kyoto rats (WKY). The increases in MAP did not differ significantly between the two strains (15+/-3 versus 10+/-2 mm Hg, respectively; n=8).

Chronic administration of aprindine during maintenance hemodialysis.

Aprindine was administered for 12 months to 8 hemodialysis patients suffering from arrhythmias. The serum aprindine concentration ranged from 0.3 to 0.

Antihypertensive treatment and the responsiveness to glutamate in ventrolateral medulla.

We have recently reported that the cardiovascular responses to excitatory amino acids are augmented in the rostral ventrolateral medulla of spontaneously hypertensive rats (SHR). In the present study, we investigated whether the responsiveness to excitatory amino acids would be normalized by antihypertensive treatment. Thus we treated 4-week-old SHR and age-matched Wistar-Kyoto (WKY) rats with either enalapril (25 mg/kg per day in drinking water) or vehicle for 8 weeks.

Ultrasonographic assessment of regional differences in atherosclerotic lesions in patients with hypertension, diabetes mellitus, or both.

We evaluated risk factors involved in regional differences in atherosclerotic lesions in patients with hypertension, diabetes mellitus, or both. Using ultrasonography, we examined the brachial, common carotid, and common femoral arteries in 65 hospitalized Japanese patients (15 controls, 18 patients with hypertension, 16 with diabetes mellitus, and 16 with both hypertension and diabetes mellitus). They ranged in age from 39 to 81 yr, mean 60.

Cardiovascular effects of nitric oxide in the rostral ventrolateral medulla of rats.

To investigate the cardiovascular role of nitric oxide (NO) in the rostral ventrolateral medulla (RVLM), NOC 18, an NO donor, was microinjected into the RVLM of rats. NOC 18 significantly decreased mean arterial pressure (MAP). Pre-treatment with an NO trapper, carboxy-PTIO, abolished the NOC 18-induced decrease in MAP.

Pressor and sympathetic responses to excitatory amino acids are not augmented in the ventrolateral medulla of Dahl salt-sensitive rats.

We assessed the pressor and sympathetic responses to microinjection of excitatory amino acids (EAA) into the rostral ventrolateral medulla (RVLM) to see whether the response would be augmented in salt-induced hypertension. Seven-week-old Dahl-Iwai salt-sensitive rats were fed either a high- (8%, n = 10) or a low- (0.3%, n = 12) salt diet for 3 weeks.

Blood pressure response during dental surgery.

To investigate blood pressure and pulse rate responses to dental surgery, 21 patients 18 to 73 years of age (mean age, 42 +/- 4 years) who visited our hospital for tooth extraction were studied. Before dental treatment, the patients underwent a mental arithmetic stress test, electrocardiography, and an anxiety evaluation with the State-Trait Anxiety Inventory. Baseline blood pressure and pulse rate were 118 +/- 4/70 +/- 3 mmHg and 69 +/- 2 beats/min, respectively.

Dystrophin, utrophin and beta-dystroglycan expression in skeletal muscle from patients with Becker muscular dystrophy.

The precise localization and semiquantitative correlation of dystrophin, utrophin and beta-dystroglycan expression on the sarcolemma of skeletal muscle cells obtained from patients with Becker muscular dystrophy (BMD) was studied using three types of double immunofluorescence. Staining intensity was measured using a confocal laser microscope. Each of these proteins was identified at the same locus on the sarcolemma.

Angiotensin II increases norepinephrine turnover in the anteroventral third ventricle of spontaneously hypertensive rats.

We evaluated the effect of angiotensin II (Ang II) administered by intracerebroventricular injection on norepinephrine turnover in the anteroventral third ventricle in adult spontaneously hypertensive rats (SHR, n = 35) and age-matched Wistar-Kyoto rats (WKY, n = 38). Ang II (100 ng) or saline (vehicle control) was administered into the cerebral ventricle 30 minutes after injection of alpha-methyl-p-tyrosine (250 mg/kg IP). Norepinephrine turnover was assessed by evaluation of the norepinephrine concentration before and 1 hour after such administration.

Cardiovascular and neurohormonal effects of intravenous adrenomedullin in conscious rabbits.

Adrenomedullin is a vasodilative peptide and shows slight homology with calcitonin gene-related peptide. In the present study, we investigated the effects of adrenomedullin on cardiovascular and neurohormonal responses in 13 conscious rabbits. The animals were chronically instrumented with bipolar electrodes on the left renal sympathetic nerve.

Seasonal variation in 24-h blood pressure pattern of young normotensive women.

To investigate the seasonal variations in ambulatory blood pressure patterns, 24-h blood pressure was measured every 15 minutes noninvasively in ten young normotensive women. Urine was collected every 4 hours. The examinations were repeated in spring, summer, autumn, and winter in a standardized living environment.

Disparate circadian variations of blood pressure and body temperature in bedridden elderly patients with cerebral atrophy.

Twenty bedridden elderly patients with normal sleep-wake cycles were studied to evaluate the circadian variations of blood pressure, pulse rate, body core temperature, cortisol, and catecholamines with a focus on their relation to cerebral atrophy. Twenty-four-hour blood pressure (BP) and pulse rate monitorings were done with simultaneous measurement of urinary bladder temperature. Urine was also collected every 4 h to measure 17-hydroxycorticosterone and catecholamines.

Long-term denopamine therapy for hemodialysis patients with chronic heart failure.

Denopamine was orally administered for more than 12 months to patients with chronic heart failure on maintenance hemodialysis. The plasma level in subjects treated with denopamine at 30 mg/day tended to be higher than that in subjects on 15 mg/day. There was no gradual increase in plasma level as the duration of therapy prolonged.

Ambulatory blood pressure monitoring in elderly hypertensives treated with the new calcium antagonist, pranidipine (OPC-13340).

Pranidipine (OPC-13340), a new dihydropyridine calcium antagonist, was given to 9 elderly hypertensive inpatients aged 64-79 years. Once-daily administration of pranidipine (1-2 mg) for 1-2 weeks decreased the 24-h average BP significantly from 167/92 mmHg to 150/83 mmHg without any change in pulse rate (PR) or the variabilities of BP and PR. The reduction of BP was observed exclusively during daytime (171/95 mmHg to 153/86 mmHg, p < 0.

[Clinicopathological studies of anti-HCV P1P4 core antibody].

Anti-P1P4 core antibody, derived from a Japanese hepatitis C virus clone, was evaluated clinicopathologically in serum samples from 40 blood donors positive for anti-HCV antibody by 2nd generation assay and in 37 patients with HCV chronic hepatitis treated with interferon. The presence of anti-P1P4 antibody was highly correlated with the presence of HCV-RNA in the blood donors. In the patients with chronic hepatitis, more than a 50% reduction in P1P4 antibody titer after interferon therapy suggested the disappearance of HCV-RNA from the blood.