Kaveolín-1 je štrukturálnym proteínom kaveol, ktoré sa zúčastňujú na regulácii mnohých signálnych kaskád. Absencia kaveolínu-1 u myší je spojená s hypertrofiou myokardu. Expresia kaveolínu-1 je znížená v hypertrofovanom srdci SHR potkana. Podávanie izoprenalínu potkanom vedie spoľahlivo k hypertrofii myokardu, avšak expresia kaveolínu-1 v tomto modeli nie je popísaná. Cieľom práce bolo hodnotiť expresiu kaveolínu-1 v modeli izoprenalínom navodenej hypertrofie myokardu u potkana. Potkanom Wistar veku 16 týždňov sme podávali izoprenalín (5 mg/kg/d, i.p.) počas 8 dní. Systolický tlak krvi a tepová frekvencia boli merané tail-cuff metódou. Zvieratá boli utratené 24 hodín po poslednej dávke. Hypertrofia myokardu bola hodnotená gravimetricky. Expresiu kaveolínu-1 v homogenátoch predsiení a komôr sme merali pomocou Western blot analýzy. Systolický krvný tlak na konci experimentu bol mierne znížený (110 ± 3 oproti 126 ± 3 mmHg, P < 0,05), tepová frekvencia bola znížená (342 ± 8 oproti 366 ± 6 min-1, P < 0,05). Všetky časti srdca boli hypertrofované približne o 30 % (P < 0,05). Expresia kaveolínu-1 v predsieňach nebola izoprenalínom zmenená. V komorách došlo k nesignifikantnému poklesu expresie kaveolínu-1 (-10 ± 3 % v ľavej komore, P = 0,065; -14 ± 5 % v pravej komore, P = 0,067). Potvrdili sme hypertrofický účinok izoprenalínu na srdce potkana a zaznamenali sme trend k zníženej expresii kaveo-línu-1 v komorách.
Kľúčové slová: hypertrofia myokardu - izoprenalín - kaveolín-1 - kaveoly - signálna transdukcia.

EXPRESSION OF CAVEOLIN-1 IN ISOPROTERENOL INDUCED MYOCARDIAL HYPERTROPHY IN THE RATS

Caveolin-1 is a structural protein of caveolae, structures involved in the regulation of multiple signaling cascades. Ablation of caveolin-1 in mice is associated with myocardial hypertrophy. Expression of caveolin-1 is decreased in the hypertrophied heart of the spontaneously hypertensive rat. Administration of isoproterenol to rats leads to cardiac hypertrophy, yet the expression of caveolin-1 in this model has not been described. The aim of this work was to evaluate the expression of caveolin-1 in isoproterenol-induced cardiac hypertrophy in the rat. Wistar rats (16 weeks old) were administered isoproterenol (5 mg/kg/d, i.p.) during 8 days. Systolic blood pressure and heart rate were measured by the tail-cuff method. Rats were sacrificed 24 hours after the last dose. Cardiac hypertrophy was evaluated gravimetrically. Expression of caveolin-1 in the homogenates of cardiac atria and ventricles was measured using Western blot analysis. Systolic blood pressure at the end of the experiment was decreased (110±3 vs. 126±3 mmHg, P<0.05), heart rate was decreased (342±8 vs 366±6 min-1, P<0.05). All parts of the heart were hypertrophied by about 30% (P<0.05). Expression of caveolin-1 in the atria was not changed after isoproterenol administration. In the ventricles, a nonsignificant decrease of caveolin-1 expression was observed (left ventricle: -10±3 %, P=0.065; right ventricle: -14±5%, P=0.067). In summary, we confirmed hypertrophic effect of isoproterenol on the rat heart and we observed a trend towards a decreased caveolin-1 expression in the ventricles.
Keywords: myocardial hypertrophy - isoproterenol, caveolin-1 - caveolae - signal transduction.

P. KŘENEK, A. FECENKOVÁ, Z. BAJUSZOVÁ, A. GAŽOVÁ, D. KUČEROVÁ, J. KLIMAS, J. KMECOVÁ, P. MUSIL, P. OCHODNICKÝ, J. KYSELOVIČ

 

 


Partneri