Biomedical subjects

B Gigante

Publications and source records attributed to B Gigante.

23 records · Page 2Linked to original sources

PubMed1995

Regulation of aldosterone biosynthesis by adrenal renin is mediated through AT1 receptors in renin transgenic rats.

The transgenic (TG) rat (mREN2)27 is characterized by overexpression of the additional mouse Ren-2d gene in the adrenal cortex with marked suppression of renal renin. We have previously shown that in salt-depleted TG rats enhanced activation of mineralocorticoid biosynthesis is associated with selective stimulation of adrenal renin. To investigate whether the local renin-angiotensin system regulates aldosterone biosynthesis in the adrenal cortex of TG rats, we studied the effects of the AT1-angiotensin subtype receptor antagonist DuP 753 on aldosterone production in 5-week-old TG rats during salt restriction. All the rats (n = 56) were shifted from regular chow to a diet containing only 0.04% NaCl for 1 week. The AT1-receptor antagonist DuP 753 (10 mg/kg per day in drinking water) was administered to 27 of these rats during low-salt diet. Subgroups of rats were killed at 0,4, and 7 days. Low-salt diet increased both adrenal renin activity (from 31 +/- 3 to 77 +/- 4 and 85 +/- 2 ng angiotensin I.h-1.mg protein-1 at 4 and 7 days, respectively; P < .001) and mRNA (by 68.4 +/- 10% and 80 +/- 17% from baseline, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex↗

PubMed1994

Enhanced adrenal renin and aldosterone biosynthesis during sodium restriction in TGR (mREN2)27.

The aim of the study was to investigate the relationships between tissue renin and the steroid production in the adrenal cortex during dietary sodium restriction in the transgenic rat (TGR) (mREN2)27. Thus the effects of a 1-wk low-sodium intake (0.04% NaCl) were studied in 5-wk-old male TGR (n = 33, systolic blood pressure = 151 +/- 3 mmHg) and in 24 age- and sex-matched outbred normotensive Sprague-Dawley (SD) rats. Measurements of plasma and tissue hormones were obtained at 0, 4, and 7 days of a low-sodium diet. Sodium restriction caused sustained increases of adrenal renin activity (from 28.5 +/- 3.5 to 87.5 +/- 4.5 ng.mg protein-1.h-1 on day 7) and of adrenal renin mRNA (+63 +/- 13 and +43 +/- 7% on days 4 and 7, respectively), whereas plasma renin activity (from 3.3 +/- 0.3 to 4.4 +/- 0.6 ng.ml-1.h-1) and renal renin activity (from 0.85 +/- 0.25 to 0.7 +/- 0.4 microgram.mg protein-1.h-1) did not change. The stimulation of the adrenal renin-angiotensin system was associated with a large increase of the aldosterone synthase cytochrome P-450 mRNA (+165 +/- 35 and +184 +/- 44%, on days 4 and 7) and of plasma aldosterone levels (from 125 +/- 32 to 338 +/- 59 pg/ml, P < 0.01). In SD rats, in spite of a more consistent increase in renal and circulating renin, mineralocorticoid production did not increase significantly. These results demonstrate that the exaggerated biosynthesis of aldosterone in TGR during sodium restriction is associated with an activation of renin in the adrenal cortex but not in the kidney.

Adrenal Glands↗

PubMed1994

[Cardiovascular risk in arterial hypertension: role of family history].

This is a short and non-comprehensive review of clinical, epidemiological and experimental observations that support the importance of the genetic background in the susceptibility to vascular injury and acute cardiovascular accidents in hypertension. In particular, previous observations suggesting the predictive role of positive family history are discussed. In addition, we introduce data obtained in our laboratory through an experiment based on rat strain crossing. This novel approach may provide a well characterized phenotype that allows gene dissection in hypertension with specific regard to cosegregation with vascular accidents.

Animals↗

PubMed1991

Separation and simultaneous high-performance liquid chromatographic determination of benzocaine and benzyl benzoate in a pharmaceutical preparation.

A simple reversed-phase high-performance liquid chromatographic method suitable for the simultaneous determination of benzocaine and benzyl benzoate in dermatological preparations is described. An internal standard method was employed, using C18 "bonded phase" silica column and a mobile phase consisting of acetonitrile - water (40:60, v/v), with absorption of the column effluent monitored at 254 nm. No sources of interference were observed. The simultaneous determination of both compounds by the method described is rapid and accurate.

Benzoates↗

PubMed1986

Puglia cooperative study on biofiltration.

Biofiltration (BF) was performed on 60 patients from 12 dialytic centers in Puglia. The protocol was 9-10.5 hours a week with 1.2 m2 PAN dialyzers. A dialysate with 140 Na+, 2-2.5 K+, 3.5-4 Ca++, 38 mEq/l acetate was used in 49 patients; the acetate was replaced by bicarbonate (35-40 mEq/l) in 11 patients. The same patients were treated for 1 year with standard acetate dialysis (49 patients) and standard bicarbonate dialysis (11 patients). The two protocols were compared on the basis of the clinical state, BUN and serum creatinine, acid-base balance, PTH, anemia, and nerve conduction velocity (NCV). Favourable effects were achieved in 55 patients. Four patients left the program because of progressive hyperhydration. BUN and serum creatinine levels showed a moderate, but insignificant increase. PTH, anemia and NCV did not worsen. BF gave better correction of metabolic acidosis in the patients undergoing acetate dialysis.

Acetates↗