Gender differences in cardiac ischemic injury and protection ‐ experimental aspects

It has been observed that significant sex differences exist already in normal heart. They involve e.g. cardiac growth, contractile function, calcium metabolism and function of mitochondria. Differences, characteristic of the normal myocardium, generate the logical presumption of the different reaction of the male and female heart to various pathogenic factors. Most of the experimental studies confirm the clinical observations: increased resistance of the female heart to ischemia/reperfusion injury was shown in dogs, rats, mice and rabbits. The already high tolerance of the adult female heart can be increased by adaptation to chronic hypoxia and ischemic preconditioning. It seems, however, that the protective effect depends on age: it was absent in young, highly tolerant heart. Both experimental and clinical studies have indicated that female gender influences favorably also the remodeling and the adaptive response to myocardial infarction. Detailed molecular and cellular mechanisms of sex differences are still unknown; they involve genomic and non‐genomic effects of sex steroid hormones, particularly the most frequently studied estrogens. The cardiovascular system is, however, influenced not only by estrogens but also by other sex hormones, e.g. androgens. The differences deserve serious consideration in clinical practice in search for proper diagnostic and therapeutic procedures. S upported by grant from the Ministry of Education 1M0510.