Chronic administration of phytoestrogen "daidzein" to ameliorate mean arterial pressure and vascular function in N-G-nitro-L-arginine methyl ester hypertensive rats/Trajna primjena fitoestrogena daidzeina poboljsava srednji arterijski tlak i vaskularnu funkciju u L-NAME stakora s povecanim krvnim tlakom

• Published in: Veterinarski arhiv p. 437
• Main Authors: Prawez, Shahid, Ahanger, Azad A, Singh, Thakur U, Mishra, Santosh K, Sarkar, Souvendra N, Rahman, Shafiqur
• Format: Journal Article
• Language: English
• Published: Sveuciliste U Zagrebu 01.07.2015
• Subjects: Arginine; Esters; Health aspects; Hypertension; Isoflavones; Physiological aspects
• ISSN: 0372-5480; 1331-8055

The 'silent killer', hypertension, leads to heart disease, stroke, kidney failure and premature death. The phytoestrogen daidzein has been associated with vaso-protective action similar to oestrogen, with minimal side effects. To explore the vaso-protective activity of daidzein and also its effect on mean arterial pressure (MAP), daidzein was chronically administered in N-G-nitro-L-arginine methyl ester (L-NAME)-hypertensive male Wistar rats for 6 weeks. The male Wistar rats were divided into three groups, namely group-A (control), group-B (L-NAME-treated) and group-C (L-NAME+daidzein treated). After completion of 42 days (6 weeks) of daidzein treatment, MAP and vascular activity were observed in all the groups. Daidzein treatment of L-NAME hypertensive rats (group-C) for 6 weeks significantly decreased the MAP (144 mm Hg) as compared to untreated-L-NAME-hypertensive rats/group-B (173.2 mm Hg), indicating the blood- pressure lowering property of daidzein. Also daidzein significantly increased acetylcholine-induced maximal relaxations of the thoracic aorta isolated from daidzein-treated ([E.sub.max] = 72.55 %) in comparison to untreated-L-NAME-hypertensive rats ([E.sub.max] = 39.33 %). The results of the present study suggest that chronic administration of daidzein (0.5 mg/kg/ day, s.c.) helps to lower blood pressure, as indicated by a decrease in MAP, and also shows vaso-protective action, as indicated by the improvement in ACh-induced relaxation. Key words: hypertension, daidzein, blood pressure, vascular function, rats Hipertenzija kao "tihi ubojica" dovodi do bolesti srca, mozdanog udara, zatajivanja bubrega i prerane smrti. Fitoestrogen daidzein, slicno kao i estrogen, djeluje zastitno na krvne zile uz minimalne popratne ucinke. S ciljem istrazivanja zastite krvnih zila, te ucinka na krvni tlak (srednji arterijski tlak--SAT), daidzein je tijekom 6 tjedana bio primjenjivan Wistar stakorima s L-NAME - hipertenzijom. Stakori su bili podijeljeni u tri skupine: skupina A (kontrola), skupina B (L-NAME lijecena) i skupina C (L-NAME + lijecena daidzeinom). Nakon 42 dana lijecenja u svim je skupinama bila analizirana funkcija krvnih zila i SAT. Lijecenje stakora oboljelih od L-NAME hipertenzije (skupina C) daidzeinom dovelo je do signifikantnog snizenja srednjega arterijskog tlaka (144 mm Hg) u usporedbi s nelijecenim oboljelim stakorima iz skupine B (173,2 mm Hg). Navedeno pokazuje ucinke daidzeina na snizavanje krvnog tlaka. Osim toga, daidzein dovodi do signifikantnog povecanja maksimalne relaksacije torakalnog dijela aorte izazvane acetilkolinom. To pokazuju vrijednosti u skupini stakora lijecenih daidzeinom ([E.sub.maks] = 72,55 %), u usporedbi sa skupinom nelijecenih stakora ([E.sub.maks] = 39,33 %). Rezultati istrazivanja potvrcuju da trajna primjena daidzeina (0,5 mg/kg/dan s.c.) pomaze snizavanju krvnog tlaka, na sto upucuje njegova smanjena arterijska vrijednost. Osim toga, opisana primjena daidzeina djeluje zastitno na krvne zile, jer poboljsava njihovu relaksaciju izazvanu acetilkolinom. Kljucne rijeci: hipertenzija, daidzein, krvni tlak, funkcije krvnih zila, stakori