ORIGINAL ARTICLES   

International Angiology 2000 June;19(2):176-83

Copyright © 2001 EDIZIONI MINERVA MEDICA

lingua: Inglese

Pharmacological assessment of adrenergic receptors in human varicose veins

Miller V. M. ^{1, 2}, Rud K. S. ¹, Gloviczki P. ¹

From the 1 Department of Surgery and 2 Physiology and Biophysics, Mayo Clinic and Foundation, Rochester, MN, USA

Back­ground. Experi­ments were to char­ac­ter­ize phar­mac­o­log­i­cal­ly adre­ner­gic recep­tors in human var­i­cose veins to the nat­u­ral trans­mit­ter nor­epi­neph­rine and to an ­extract of Rus­cus.
Meth­ods. Great­er saph­e­nous veins and var­i­cose trib­u­tar­ies from ­patients under­go­ing elec­tive sur­gery for pri­mary var­i­cose dis­ease and por­tions of great­er saph­e­nous veins from ­patients under­go­ing periph­er­al arte­ri­al recon­struc­tion (con­trol) were sus­pend­ed for the meas­ure­ment of iso­met­ric force in organ cham­bers. Con­cen­tra­tion ­response ­curves were ­obtained to nor­epi­neph­rine or the ­extract of Rus­cus acu­lea­tus in the ­absence and pres­ence of selec­tive antag­o­nists of alpha, and alpha2 adre­ner­gic recep­tors.
­Results. Nor­epi­neph­rine and Rus­cus ­extract ­caused con­cen­tra­tion-depen­dent con­trac­tions in all veins. Con­trac­tions to nor­epi­neph­rine were great­er in con­trol veins than in var­i­cose trib­u­tar­ies. Con­trac­tions to the ­extract were great­er in var­i­cose trib­u­tar­ies than in great­er saph­e­nous veins from var­i­cose ­patients. Con­trac­tions to nor­epi­neph­rine were ­reduced sim­i­lar­ly by alpha1 and alpha2-adre­ner­gic ago­nists in con­trol and var­i­cose veins but to a great­er ­extent by alpha2-block­ade in great­er saph­e­nous veins from var­i­cose ­patients. Con­trac­tions to Rus­cus ­extract were not ­reduced by alpha­ad­re­ner­gic block­ade in con­trol veins but were ­reduced by alpha2-adre­ner­gic block­ade in var­i­cose veins.
Con­clu­sions. These ­results sug­gest a dif­fe­ren­tial dis­tri­bu­tion of alpha adre­ner­gic recep­tors on great­er saph­e­nous veins from non-var­i­cose ­patients com­pared to those with pri­mary var­i­cose dis­ease. Ven­o­trop­ic ­agents from plant ­extract prob­ably exert ­effects by way of mul­ti­ple recep­tor and non-recep­tor medi­at­ed ­events.