[Show abstract][Hide abstract] ABSTRACT: A 64-year-old woman complaining of severe lumbar pain was admitted to our hospital because of the finding of pre-existing mitral valve regurgitation on examination. Laboratory data revealed the proximal type of renal tubular acidosis, renal glucosuria, phosphaturia, generalized aminoaciduria and low-molecular-weight proteinuria. She did not have any cause of these tubular dysfunctions, and was diagnosed as adult idiopathic Fanconi syndrome. Dual energy X-ray absorptiometry (DEXA) revealed a reduction of bone mineral density in the lumbar spine to about 65% of the age-and gender-matched control value. Alkali agents (sodium citrate and potassium citrate), calcium lactate and 1 alpha-hydroxyvitamin D3 were administered. Bone mineral density estimated with DEXA improved with a reduction of serum alkali phosphate and disappearance of lumbar pain, and was restored to 82% of the age-and gender-matched control value after about 30 months of treatment. DEXA is useful for the long-term follow-up study of bone mineral density in a patient with Fanconi syndrome.
No preview · Article · Apr 1997 · Nippon Jinzo Gakkai shi
[Show abstract][Hide abstract] ABSTRACT: Dietary Ca is an important modulator of arterial blood pressure in humans and rats. Since the kidney plays a key role in the pathogenesis of hypertension, the effect of a low Ca diet (0.01%Ca) on blood pressure and pressure natriuresis response was studied in Sprague-Dawley rats. In addition, a possible role of the renin-angiotensin system in the development of hypertension and an altered pressure natriuresis response resulting from low dietary Ca intake was investigated. In the low Ca diet group, systolic blood pressure determined by the tail-cuff method was significantly higher than in the normal Ca diet group (1.1%Ca) 1 week after the diet (113.0 +/- 7.1 vs. 105.0 +/- 9.5 mmHg, p < 0.05). Furthermore, low dietary Ca treatment significantly inhibited the water and sodium excretory responses to acute elevation of renal perfusion pressure. Treatment with an inhibitor of angiotensin converting enzyme, captopril (30 mg/kg/day), attenuated both the development of hypertension and the reduced pressure natriuresis response observed in Ca-deficient rats. Although plasma renin activity was not different between the low and normal Ca diet groups after the 2-week dietary regimen, the pressor response to angiotensin II injection was significantly greater in the low Ca diet group. These results indicate a possible involvement of the renin-angiotensin system in the development of hypertension and the inhibitory effects of the pressure natriuresis response caused by low dietary Ca intake, via enhanced sensitivity to angiotensin II.
No preview · Article · Jun 1994 · Nippon Jinzo Gakkai shi
[Show abstract][Hide abstract] ABSTRACT: To determine the role of endothelium-derived nitric oxide (EDNO) in mediating the natriuretic response to acute extracellular volume expansion (ECVE) with isotonic saline (3% of body weight per hour), the diuretic and natriuretic responses to ECVE were studied in anesthetized Sprague-Dawley rats during the intravenous infusion of an EDNO synthesis inhibitor, NW-nitro-L-arginine methyl ester (L-NAME). Intravenous infusion of L-NAME at the dose of 5 micrograms/kg/min significantly inhibited the diuresis and natriuresis in response to ECVE by 58% and 67%, without altering arterial pressure, effective renal plasma flow, glomerular filtration rate and basal excretory function. This inhibitory effect of L-NAME on the diuretic and natriuretic responses to ECVE was attenuated by the infusion of the EDNO synthesis precursor, L-arginine (1mg/kg/min), but not by D-arginine. In addition, pretreatment with 0.3 mg/kg of the angiotensin II receptor antagonist, L-158,809, normalized the diuretic and natriuretic responses to ECVE in L-NAME-treated rats, suggesting an angiotensin-II-dependency of the reduced renal excretory response to ECVE during EDNO synthesis inhibition. Neither L-arginine nor L-158,809 alone significantly altered the renal excretory response to ECVE compared with vehicle-treated control rats. These results suggest that EDNO might play an important role in the regulation of sodium and water excretion during ECVE, and indicate a possible interaction between EDNO and angiotensin II on the renal excretory function.
No preview · Article · Apr 1994 · Nippon Jinzo Gakkai shi
[Show abstract][Hide abstract] ABSTRACT: The importance of the distribution of intrarenal blood flow in the regulation of various renal functions, such as urine concentration and sodium excretion, has been well recognized. However, there have been no reliable methods to measure local flow in the kidney in vivo. The present study demonstrated the usefulness of contrast ultrasonography combined with injection of sonicated 5% albumin for assessment of the distribution of renal cortical blood flow in eleven mongrel dogs. The left kidney was displayed by tomographic echography, and microbubbles of sonicated albumin were injected into the abdominal aorta above the left renal artery. Video density time curves were generated and fitted to a time-intensity curve. Intrarenal infusion of acetylcholine (4.0 micrograms/kg/min) increased renal blood flow (RBF) from 2.5 +/- 0.3 to 4.6 +/- 1.0 ml/min/g kwt (p < 0.01), and norepinephrine (0.5 microgram/kg/min) decreased RBF from 2.5 +/- 0.3 to 1.2 +/- 0.5 ml/min/g kwt (p < 0.01). There were significant positive correlations between percent change in RBF and peak intensity and area under the curve, which were calculated with a time-intensity curve. Furthermore, the inner/outer renal cortex ratio of peak intensity significantly increased during acetylcholine infusion (0.72 +/- 0.11 vs 0.86 +/- 0.09; p < 0.01), whereas no significant change was observed during norepinephrine infusion. These results suggest that renal contrast ultrasonography may be useful for real-time assessment of the distribution of renal cortical blood flow in vivo.
No preview · Article · Mar 1994 · Nippon Jinzo Gakkai shi
[Show abstract][Hide abstract] ABSTRACT: It has been described that a rapid worsening in renal function is uncommon in the elderly patient with lupus nephritis. We report a case of a 76-year-old man with rapidly progressive lupus nephritis. On admission, laboratory studies revealed massive proteinuria, telescoped urine, thrombocytopenia and azotemia. Hypocomplementemia and the positive presence of anti-DNA antibody and lupus anticoagulant were also noted. Because of a rapid deterioration of renal function, he was started on a regimen of steroid pulse therapy and plasmapheresis. Serum levels of complements gradually increased after initiation of these treatments, and three weeks later, improvements of renal function and nephrotic syndrome were obtained. A renal biopsy specimen taken five months after admission showed diffuse membranous glomerulonephritis. In addition, we examined renal arterial blood flow with Doppler ultrasound, and significant improvements of the velocity and pulsatility were observed during recovery of the renal function.
No preview · Article · Nov 1993 · Nippon Jinzo Gakkai shi