Do binucleate cardiomyocytes have a role in myocardial repair? Insights using isolated rodent myocytes and cell culture.

Neonatal and adult cardiomyocytes were isolated from rat hearts. Some of the adult myocytes were cultured to allow for cell dedifferentiation, a phenomenon thought to mimic cell changes that occur in stressed myocardium, with myocytes regressing to a fetal pattern of metabolism and stellate neonatal shape.Using fluorescence deconvolution microscopy, cells were probed with fluorescent markers and scanned for a number of proteins associated with ion control, calcium movements and cardiac function.

Efficacy of ischaemic preconditioning in the eNOS overexpressed working mouse heart model.

We recently demonstrated that exogenous nitric oxide (NO) acts as a trigger for preconditioning in the isolated rat heart model. There is however little data concerning the effects of elevated cardiac endothelial nitric oxide synthase (eNOS) expression on myocardial tolerance to ischaemia. Similarly, the effects of gender and eNOS overexpression on ischaemic preconditioning is unknown.

Short- and long-term effects of melatonin on myocardial post-ischemic recovery.

Melatonin, the chief secretory product of the pineal gland, has been shown to protect the heart against ischemia-reperfusion injury. This was attributed to its free radical scavenging and broad-spectrum antioxidant properties. The possibility that melatonin may act via its receptor and intracellular signaling, has not yet been addressed in this regard.

The temporal relationship between p38 MAPK and HSP27 activation in ischaemic and pharmacological preconditioning.

An ischaemic preconditioning protocol and subsequent sustained ischaemia were characterized by activation and attenuation of p38 MAPK phosphorylation, respectively. However, the significance of events downstream of p38 MAPK needs investigation. Therefore the temporal relationship between phosphorylation of p38 MAPK and its downstream substrate HSP27 was studied during either an ischaemic or beta-adrenergic preconditioning protocol and during sustained ischaemia.