Influence of secretin and L-NAME on vascular permeability in the coronary circulation of intact and diabetic rats

The permeability in the intact and diabetic rat coronary circulation after administration of secretin (3.0 mu mol/kg i.v.), an inhibitor of NOS (nitric oxide synthase), and L-NAME (N-G-nitro-L-arginine-methyl ester hydrochloride) (1 mg/kg i.v.), and both substances given together, were studied. To measure protein extravasation Evans blue dye was used as a marker of vascular permeability. The vascular permeability of the left ventricle did not differ in intact and diabetic rats. In the diabetes state increased permeability of atria was observed. Administration of secretin did not influence the coronary vascular permeability in either the intact or the diabetic rats. L-NAME increased the atria permeability and did not change left ventricle permeability. In diabetes, injection of t-NAME caused a decrease in the permeability in both the atria and left ventricle. In intact rats secretin diminished the L-NAME effect in the atria. In diabetic rats co-administration of secretin + L-NAME increased the permeability of the atria and left ventricle, but L-NAME administered alone decreased them. Secretin modified the effect of L-NAME on coronary permeability in intact and diabetic rats. (C) 2001 Elsevier Science B.V. All rights reserved.