Down regulation of immuno-detectable cardiac connexin-43 in BALB/c mice following acute fasting

Acute starvation effects for connexin-43 protein expression, in the heart, had not been previously explored. Hence we examined acute fasting on the myocardial immuno-histochemical expression of connexin-43 in 3 groups of 8-week old female BALB/c mice. Groups consisted of control mice (n = 5), fasting for 24 h (N = 5) and 48 h (N = 3). Under light microscopy all control fed cases revealed the presence of some immuno-detectable staining for connexin-43 that is either present or weakly observed in some or all of the regions of interest, that include the cross-sectional left ventricular sub-endocardium, mid-myocardium and papillary muscle. Whereas mice that underwent 24 or 48 h of acute starvation, connexin-43 expression was either difficult to detect visually (N = 3) or was completely absent (N = 5) at 40× magnification using a light microscope. In starved mice with no membrane staining for connexin-43 we observed an increase in the intracellular accumulation of cytoplasmic connexin-43 expression.