Dietary omega-3 fatty acids attenuate myocardial arrhythmogenic factors and propensity of the heart to lethal arrhythmias in a rodent model of human essential hypertension.

Objective: Hypertension-induced myocardial remodeling is known to be associated with increased risk for malignant arrhythmias and alterations in electrical coupling protein, connexin-43 (Cx43), may be involved. We investigated whether omega-3 fatty acids intake affects abnormalities of Cx43 as well as protein kinase C (PKC) signaling and myosin heavy chain (MyHC) profile at the early and late stage of hypertension in the context of the heart's susceptibility to ventricular fibrillation and ability to restore sinus rhythm.

Methods: Untreated young and old male spontaneously hypertensive rats (SHRs) and age-matched normotensive rats were compared with animals supplemented by omega-3 (eicosapentaneoic acid + docosahexaneoic acid, 200 mg/kg body weight/day) for 2 months.

Electrophoretic mobility of cardiac myosin heavy chain isoforms revisited: application of MALDI TOF/TOF analysis.

The expression of two cardiac myosin heavy chain (MyHC) isoforms in response to the thyroid status was studied in left ventricles (LVs) of Lewis rats. Major MyHC isoform in euthyroid and hyperthyroid LVs had a higher mobility on SDS-PAGE, whereas hypothyroid LVs predominantly contained a MyHC isoform with a lower mobility corresponding to that of the control soleus muscle. By comparing the MyHC profiles obtained under altered thyroid states together with the control soleus, we concluded that MyHCα was represented by the lower band with higher mobility and MyHCβ by the upper band.