Innate immunity is activated in hearts injured in different ways, evident as cytokine release from the heart, activation of toll-like receptors involved in recognizing danger, and activation of the transcription factor nuclear factor kappa B. Nuclear factor kappa B regulates gene programmes involved in inflammation as well as the resolution of inflammation.
In the heart, activation of ADORA2A enhances cAMP production through αGs proteins (Sommerschild & Kirkeboen, 2000) and overexpression results in increased contractility and sarcoplasmic reticulum Ca2+ uptake (Hamad et al, 2010) as well as cardioprotection in ischemia and reperfusion damage (Urmaliya et al, 2009).
In non-diabetic hearts, activation of fetal genes is a protective mechanism [ 15- 17] that accompanies pathological hypertrophy [ 17- 21].
In chronic heart failure, activation of the adrenergic nervous system is associated with increased mortality, and inotropic therapy worsens outcomes [ 5].
The insensitivity of the crucian carp heart to catecholamines prevents unnecessary activation of the heart under oxygen shortage, if hypoxia/anoxia causes a surge of catecholamines into the blood for activation of stress responses, e.g. glycogenolysis in the liver [ 41].
Myocardial contrast echocardiography (MCE) can induce bioeffects in rat hearts by local activation of the contrast agent gas bodies.
As shown in Figure 4C CTGF-TG hearts displayed an activation of the Akt and JNK pathways.
Others, however, have disagreed with these findings, suggesting that the effects of iPOST, as well as IPC, were preserved in isolated rabbit hearts through the activation of the adenosine A1 receptor and KATP channels (see Box 1) (Donato et al., 2007).
In the heart, reliable activation of Ca2+ release from the sarcoplasmic reticulum during the plateau of the ventricular action potential requires synchronous opening of multiple CaV1.2 channels.
In many different tissues, most notably in the heart, the activation of these channels has been shown to protect the cells against different kinds of metabolic stresses.
