Application of amperometric detection to the analysis of the diffusion and O-methylation of a catecholamine and a catechol steroid across the blood vessel wall.
A novel amperometric detection procedure was developed to determine the ability of the catechol, 2-hydroxyestradiol (2OHE2), to diffuse through and be O-methylated during its passage from the lumen to the adventitial surface of the rabbit ear artery. The diffusion and O-methylation of d-norepinephrine (d-NE) also was determined. When arteries were perfused with either 2OHE2 or d-NE (10 microM), the bulk of the material effluxing from the adventitial surface was O-methylated. The vessel wall offered a considerable barrier to the diffusion of both NE and 2OHE2, because the concentrations of NE and 2OHE2 found in the solution perfusing the adventitial surface were as much as 1,000-fold lower than their concentration in the intralumenal perfusion stream. It is concluded that the blood vessel wall offers a significant physical and metabolic barrier to the penetration of unchanged 2OHE2 and NE.
Panek
D U
DU
Department of Pharmacology and Toxicology, West Virginia University Health Sciences Center, Morgantown.
Stitzel
R E
RE
de la Lande
I S
IS
Head
R J
RJ
D000818:Animals; D001808:Blood Vessels / Q000378:metabolism*; D004058:Diffusion; D004423:Ear / Q000098:blood supply; D004563:Electrochemistry; D004958:Estradiol / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics; D066298:In Vitro Techniques; D008297:Male; D008745:Methylation; D009119:Muscle Contraction; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism* / Q000493:pharmacokinetics; D010084:Oxidation-Reduction; D011817:Rabbits; D012039:Regional Blood Flow
D004958:Estradiol; C001390:2-hydroxyestradiol; D009638:Norepinephrine