Potentiation by endothelin-1 and vasopressin of sympathetic vasoconstriction in male and female rats.

The aim of this study was to analyse the modulatory role of endothelin-1 and vasopressin in sympathetic vasoconstriction, and whether there are gender differences in this modulatory role. Electrical field stimulation (4 Hz, 0.2 ms pulse duration at supramaximal voltage of 70 V, for 1 s), applied to isolated segments from rat tail arteries, produced a contraction that was lower in the vascular segments from female than in those from male rats.

Pharmacokinetic characteristics and tissue residues for marbofloxacin and its metabolite N-desmethyl-marbofloxacin in broiler chickens.

Objectives: To determine pharmacokinetic characteristics of marbofloxacin after a single IV and oral administration and tissue residues after serial daily oral administration in chickens.

Animals: 40 healthy broiler chickens.

Procedure: Two groups of chickens (groups A and B; 8 chickens/group) were administered a single IV and oral administration of marbofloxacin (2 mg/kg).

Relaxation by urocortin of human saphenous veins.

Urocortin, an endogenous peptide structurally related to corticotropin-releasing factor (CRF), has potent cardiovascular effects, suggesting that it may be of significance in cardiovascular regulation. The objective of this study was to analyse the effects of urocortin and its action mechanisms on human blood vessels. To this, 3 mm long segments from human saphenous veins were prepared for isometric tension recording in an organ bath.

Synthesis of Enantiopure syn-beta-Amino Alcohols. A Simple Case of Chelation-Controlled Additions of Diethylzinc to alpha-(Dibenzylamino) Aldehydes.

Enantiomerically pure syn-2-amino alcohols 6 are prepared by addition of diethylzinc to chiral alpha-(dibenzylamino) aldehydes 4. The addition is highly stereoselective, leading to syn-2-(dibenzylamino) alcohols 5 with excellent diastereomeric excesses (76-98%). Debenzylation of 5 by hydrogenolysis on Pearlman's catalyst yields quantitatively the amino alcohols 6.