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D Bichet

Publications and source records attributed to D Bichet.

43 records · Page 3Linked to original sources
PubMed1982

Renal intracortical blood flow and renin secretion after denervation by 6-hydroxydopamine.

A new method of unilateral renal denervation (DNX) was developed in dogs by rapidly injecting 6-hydroxydopamine (6-OHDA) into the renal artery with simultaneous collection of the venous effluent to avoid systemic effects. The procedure induced a 93.1 +/- 2.7% destruction of the adrenergic innervation as assessed by a histochemical fluorescence technique. A comparative study of both kidneys was carried out 3 days after DNX. Renal blood flow (RBF) and its cortical distribution were measured with radioactive microspheres at mean perfusion pressures of 117 mmHg (1 mmHg = 133.322 Pa) (normotension) and 70 mmHg (hypotension). The comparison of renal perfusion between kidney halves revealed a remarkable perfusion symmetry during normotension and hypotension in both the intact and the DNX kidney. Renal DNX by 6-OHDA did not alter RBF when the kidneys were perfused at normotension. During hypotension, RBF fell by 45% on the control side, while a nonsignificant decrease was noted in the DNX kidney. The redistribution of blood flow to inner cortical zones was less marked in the DNX side during hypotension. The DNX kidney did not release renin during normotension, but exhibited a normal renin response to hypotension. These data are partly in agreement with classical denervation models, and indicate that (1) denervation by 6-OHDA protects renal perfusion during hypotension; and (2) the redistribution of blood flow to inner cortical nephrons is independent of release of renin, but modulated by adrenergic innervation.

Animals↗
PubMed1982

Role of vasopressin in abnormal water excretion in cirrhotic patients.

Twelve stable cirrhotic patients with ascites received a 20 mL/kg water load. Seven patients had abnormal water excretion (27.3% +/- 5.4% of the water load in 5 hours) and a minimal urine osmolality of 262 mosmol/kg water. Five patients excreted 82.6% in 5 hours and had a minimal urine osmolality of 65 mosmol/kg water. Mean plasma arginine vasopressin values after water load were significantly higher in Group 1 (1.34 +/- 0.36 pg/mL) than in Group 2 (undetectable). An effective blood volume lower in Group 1 than Group 2 patients was suggested by a lower plasma albumin (2.5 versus 3.3 g/dL, p less than 0.02), a higher pulse rate (96 versus 72, p less than 0.001), a higher plasma renin activity (7.8 versus 1.5 ng/mL . h, p less than 0.005), a higher plasma aldosterone (66 versus 21 ng/dL, p less than 0.05), and a lower urinary sodium excretion (2.7 versus 14.2 meq Na/5 h, p less than 0.005). The results suggest that nonosmotic stimulation of vasopressin secondary to a decrease in effective blood volume is an important factor in the abnormal water excretion of cirrhosis.

Adult↗