Forskolin preferentially dilates the afferent arteriole in the canine kidney.

Intrarenal infusion of forskolin (0.2 microgram/kg/min) in anesthetized dogs increased renal blood flow (RBF) and glomerular filtration rate (GFR) to the same degree but did not change the mean arterial pressure or heart rate. Forskolin also increased urine flow and urinary sodium excretion.

Intrarenal vascular sites of action of adenosine and glucagon.

Our purpose was to localize the intrarenal vascular sites of action of adenosine and glucagon. Renal blood flow (RBF) and glomerular filtration rate (GFR) were measured in anesthetized dogs, and renal perfusion pressure (RPP) was varied by an adjustable aortic clamp. At normal RPP, RBF was increased by all agents.

Renal vasodilatation induced by DOI, a 5-HT2 receptor agonist, in the canine kidney.

An intrarenal infusion of (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), a selective 5-HT2 agonist, at a rate of 5 micrograms/min in anesthetized dogs resulted in an increase in renal blood flow (RBF) without any transient decrease as usually observed during the infusion of 5-HT. During the infusion, urine flow (UF) and urinary sodium excretion rates (UNaV) increased along with RBF while the mean arterial pressure and glomerular filtration rate did not change. After pretreatment with ritanserin, a selective 5-HT2 antagonist, DOI failed to increase RBF, UF and UNa V.

Effects of cromakalim, a potassium channel opener, on regional blood flow in conscious spontaneously hypertensive rats.

We studied the effects of cromakalim, a potassium channel opener, on regional blood flow in conscious spontaneously hypertensive rats using microspheres. Cromakalim produced significant hypotension and increased blood flow in the stomach, skeletal muscle and skin. Calculated vascular resistances decreased in many organ vascular beds.

[Surgical repair of total anomalous pulmonary venous connection in neonates and infants--prevention for pulmonary venous obstruction at the site of anastomosis].

From October, 1980, to June, 1987, thirty-eight infants less than one year old underwent correction for total anomalous pulmonary venous connection (TAPVC). Overall operative mortality and late mortality were 13% and 6%, respectively. Residual pulmonary hypertension was noted in 4 patients: three had pulmonary venous obstruction at the site of atrial anastomosis (PVOA) and one had supracardiac (Ia) lesion left after repair of mixed type (IV: Ia + III) of TAPVC.

Elevated angiotensinogen mRNA levels in rat liver by nephrectomy.

The expression of the angiotensinogen gene was studied in nephrectomized rats with and without adrenal glands. Angiotensinogen mRNA was measured by a sensitive radiodensitometric hybridization assay. Angiotensinogen mRNA levels in the liver increased 5 times by nephrectomy alone and 2.

[Evaluation of left ventricular function after Jatene's operation for transposition of the great arteries--influence of age at repair].

The postoperative left ventricular function (LV) of Jatene's operation for transposition of the great arteries (TGA) was evaluated by angiocardiography and echocardiography in 39 patients. In 16 patients repaired at less than 3 months of age, left ventricular endodiastolic volume (LVEDV) was significantly decreased at the angiography 2 months after repair: form 215 +/- 685% normal of preoperative LVEDV to 120 +/- 14% normal postoperatively (p less than 0.05) in 7 patients with simple TGA (Group IA), and from 220 +/- 64% normal to 130 +/- 33% normal (p less than 0.

Effects of thyroid hormone on angiotensinogen and renin messenger RNA levels in rats.

We studied the expression of angiotensinogen and renin genes in rats treated with 3,3',5-triiodo-L-thyronine (T3) at doses of 0.1 and 1 mg/kg of body weight. Liver angiotensinogen mRNA increased by 2 to 3 times 8 to 12 hours after T3-treatment.

Regulation of liver angiotensinogen and kidney renin mRNA levels by angiotensin II.

The current study was designed to evaluate the role of angiotesin II (ANG II) in the regulation of renin mRNA and angiotensinogen mRNA levels. We investigated the changes in renin mRNA levels in the kidney and angiotensinogen mRNA levels in the liver induced by ANG II infusion and by inhibition of the endogenous renin-angiotensin system with enalapril or saralasin in rats. mRNAs for angiotensinogen and renin were measured by densitometric analysis of Northern blot hybridization.

Endogenous angiotensin II regulates hepatic angiotensinogen production.

We have investigated the effects of endogenous angiotensin II (ANG II) on hepatic angiotensinogen mRNA levels in rats. Changes in endogenous ANG II were induced by various sodium intakes (standard-, low-, and high-sodium) or by enalapril treatment. In a low sodium state for 2 weeks, angiotensinogen mRNA levels and plasma ANG II concentration increased 1.

Effect of angiotensin II on angiotensinogen production in adrenalectomized rats.

The present study was performed to examine the effect of angiotensin II on hepatic angiotensinogen production in adrenalectomized rats. The hepatic angiotensinogen mRNA levels in rats without adrenal glands increased 2.8-fold 4 h after the start of angiotensin II infusion.

Renal hemodynamic responses to 5-hydroxytryptamine (5-HT): involvement of the 5-HT receptor subtypes in the canine kidney.

The study was designed to define the serotonin (5-HT) receptor subtypes in the canine kidney. An intrarenal infusion of 5-HT at a dose of 5 micrograms/min in anesthetized dogs resulted in a biphasic response of renal blood flow which decreased transiently then increased above the control level during prolonged infusion. The decrease of renal blood flow was abolished by infusion of methysergide but not by ketanserin, and the subsequent increase was abolished by infusion of either ketanserin or methysergide.

Arterial switch operation for transposition of the great arteries, with special reference to left ventricular function.

Between June 1984 and September 1987, 48 patients underwent Lecompte's modification of the arterial switch operation for transposition of the great arteries, including transposition with intact ventricular septum with preparatory pulmonary artery banding (n = 18), with patent ductus arteriosus (n = 11), with dynamic left ventricular outflow tract obstruction (n = 4), and transposition with ventricular septal defect (n = 15). Ages ranged from 12 days to 36 months (mean 8 months) and weights ranged from 2.7 to 12.

[Current status of Jatene's operation].

The current status of Jatene's operation for transposition of the great arteries was described by showing the analysis of our results of an arterial switch operation addition to the review of the literatures. The arterial switch operation recently has become the operation of first choice because of its low surgical mortality (4.5% in author's series) and low incidence of postoperative complication.

Captopril and hydralazine suppress atrial natriuretic peptide (ANP) gene expression in the ventricles of spontaneously hypertensive rat.

We investigated the influences of captopril (CAP) and hydralazine (HYD) on the ANP mRNA level in the hypertrophied left ventricle (LV) of spontaneously hypertensive rats (SHR). Male SHRs (16 weeks of age) were given CAP (35 mg/kg/day) or HYD (3.5 mg/kg/day) for two weeks.

[Anatomic correction of transposition of the great arteries].

The present status of the surgical treatment of transposition of the great arteries was described by showing the analysis of our results of an arterial switch operation in addition to the review of the literatures. The arterial switch operation recently has become the operation of first choice because of its low surgical mortality (author 4.5%) and low incidence of postoperative complication.

[Total repair of complete atrioventricular canal: relationship between age at operation and late results].

Twenty five consecutive patients with complete atrioventricular canal (CAVC) underwent one-stage operation from April 1981 to Aug. 1987. Average ages at operation was 18 months (2 to 72) and average weight was 7.

Effects of calcium and ouabain on the release of atrial natriuretic factor.

In order to examine the role of calcium in the secretory process of atrial natriuretic factor (ANF), we studied the effects of hypercalcaemia and ouabain on the plasma concentration of immunoreactive ANF, and the effect of calcium on immunoreactive ANF release from isolated rat atria. Anaesthetized dogs were treated with CaCl2 infusion, ouabain or phenylephrine injection. With CaCl2 infusion, serum calcium and plasma immunoreactive ANF respectively increased to three and four times their basal levels.

Effect of changes in sodium balance on renin, angiotensinogen and atrial natriuretic factor messenger RNA levels in rats.

The expression of messenger (m)RNA for renin, angiotensinogen and atrial natriuretic factor (ANF) was investigated in rats on different sodium intakes. Messenger RNA was measured by a radiodensitometric hybridization assay. In the high-sodium state, renal renin mRNA decreased, but it increased in the low-sodium state.

Effects of hypercalcemia and ouabain on plasma atrial natriuretic polypeptide in anesthetized dogs.

For the purpose of examining the role of calcium ion in the secretory process of atrial natriuretic polypeptide (ANP), we studied the effects of hypercalcemia and ouabain on plasma concentration of immunoreactive ANP (irANP). Pentobarbital sodium-anesthetized dogs were treated with calcium chloride infusion (0.136 mmol.

Calcitonin gene-related peptide(CGRP) stimulates the release of atrial natriuretic peptide(ANP) from isolated rat atria.

The effect of calcitonin gene-related peptide(CGRP) on the release of atrial natriuretic peptide(ANP) was studied in spontaneously beating, isolated rat atria. CGRP stimulated the ANP release in a dose-dependent manner. When the atria were incubated with a combination of phentolamine, propranolol, and atropine, these antagonists blocked neither the rise in ANP release nor the positive chronotropic and inotropic effects of CGRP.

Sodium balance effects on renin, angiotensinogen, and atrial natriuretic polypeptide mRNA levels.

The expressions of the renin, angiotensinogen, and atrial natriuretic polypeptide (ANP) genes were studied in rats with varying sodium intakes. mRNAs for angiotensinogen and renin were measured by a sensitive radiodensitometric hybridization assay. ANP mRNA was determined by a dot-blot hybridization assay.

Renal effects of leukotrienes C4 and D4 in anesthetized dogs.

We investigated the effects of leukotrienes (LTs) C4 and D4 on renal function and hemodynamics of dogs. LTC4 (0.5 microgram/min, infused into the renal artery), but not LTD4 (1 microgram/min), caused an increase in renal blood flow, urine flow, urinary excretion of sodium and potassium, and rate of free water reabsorption, with a concomitant rise in systemic blood pressure.

Effects of an antihypertensive vasodilator, pinacidil, on regional blood flow in conscious spontaneously hypertensive rats.

Using a radioactive microsphere method, the effects of hydralazine and a new antihypertensive vasodilator, pinacidil, on systemic and regional hemodynamics were examined and compared in conscious Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). A single intravenous administration of pinacidil decreased mean blood pressure in a dose dependent fashion (0.03-0.