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Biomedical subjects

G Richet

Publications and source records attributed to G Richet.

At least 55 records · Page 3Linked to original sources
PubMed1987

Extraneuronal production of dopamine by kidney slices in normo and hypertensive rats.

Synthesis of dopamine (DA) was studied in cortical slices of Sprague-Dawley (SD) rat kidneys incubated with L-DOPA (10(-6) M). In morphological studies, formaldehyde-induced histofluorescent deposits were detected at the apical pole of the convoluted parts of the proximal tubules. Elsewhere along the nephron, no positive reaction appeared. DOPA decarboxylase inhibitors suppressed the advent of the deposits, but prior denervation did not. Biochemical studies showed: (a) slices produced 2.2 nmol mg-1 protein, glomeruli 0.2 and cytosol 43 nmol. In absence of L-DOPA or in presence of DOPA decarboxylase inhibitors, DA production was suppressed. Prior denervation did not influence DA production; (b) DA synthesis increased with sodium concentration of the milieu (range 95 to 152 mmol). Adult spontaneously hypertensive rats (SHR) produced less DA than SD or normotensive Wistar-Kyoto, at any sodium concentration from 95 to 142 mmol. This discrepancy could be related to the pathogenesis of hypertension.

Animals↗
PubMed1986

Characterization of monoclonal antibodies specific for human Tamm-Horsfall protein.

Fifteen monoclonal antibodies have been produced to human Tamm-Horsfall protein (THP), identifying at least seven distinct epitopes. The antibodies have been used to isolate from serum an immunoreactive protein which comigrates with urinary THP. In addition, the antibodies may prove useful to set up an immunoenzymoassay for urinary THP as well as for immunoaffinity purification.

Antibodies, Monoclonal↗
PubMed1986

Effects of tertatolol in hypertensive patients with chronic renal failure.

Chronic renal failure (CRF) is often associated with hypertension, as a cause or a consequence. We studied the changes in blood pressure (BP), heart rate (HR), renal function (as measured by creatinine clearance), and plasma renin activity (PRA) in 19 hypertensive patients with CRF before, during and after oral administration once a day for at least 30 days of 5 mg tertatolol, a new beta-blocker. All patients were free of any antihypertensive medication for at least 1 month before administration of tertatolol. The dose of tertatolol given in this study was the same as that commonly used in patients with normal renal function. From day 0 to day 30 of tertatolol, measurements in the supine position were as follows: systolic BP (SBP) decreased from 168.4 +/- 4.6 to 145.3 +/- 4.3 mm Hg (p less than 0.01); diastolic BP (DBP) decreased from 106.1 +/- 2.4 to 87.1 +/- 2.0 mm Hg (p less than 0.01); HR decreased from 77.9 +/- 1.6 to 63.2 +/- 1.7 b.p.m. (p less than 0.01); PRA decreased from 1.816 +/- 0.521 to 1.052 +/- 0.323 ng/ml/h (p less than 0.01). Creatinine clearance remained stable: 37.1 +/- 4.1 versus 37.1 +/- 4.7 ml/min/1.73 m2 (not significant). Similar results (for SBP, DBP, HR and PRA) were obtained in the erect position. It is concluded that tertatolol in hypertensive patients with CRF: significantly lowers BP and HR without excessive bradycardia, significantly lowers PRA, the most important decrease being observed for the highest initial PRA, does not alter renal function, and has a good clinical acceptability.

Adrenergic beta-Antagonists↗
PubMed1985

Proximal tubule dopamine histofluorescence in renal slices incubated with L-dopa.

Renal cortex slices were incubated with amine precursors L-dopa, or L-5-HTP. Localization of synthesized amines, dopamine or serotonin, was examined by means of histofluorescence methods. Formaldehyde-induced fluorescence was present in the proximal convoluted tubule and not in the pars recta or other segments of the tubules after incubation in the presence of 10(-3) to 10(-7) M L-dopa. Tubule-induced fluorescence was not seen in the presence of an inhibitor of dopa-decarboxylase or in the absence of sodium. It was independent of innervation. It is concluded that dopamine and serotonin are accumulated and likely formed within proximal convoluted tubular cells.

5-Hydroxytryptophan↗