Vliv hypoxie a tlakového přetížení na G proteiny řízenou signalizaci v myokardu potkana

Abstract

Conclusion Hypertophy In conclusion, our present study revealed that sustained pressure overload applied in newbom rats does not influence distribution of G proteins in immature myocardium, but appreciably reduces the content of G.clL and increases the level of Gocr proteins in myocardium from adult rats. The finding of distinct regulation of the long and short G,o isoforms during normal development and during pathological cardiac growth strongly suppořts the notion about unequal behavior and possibly function of these proteins [95]. Similar decrease in AC activity determined under diffbrent stimulation conditions together with a lower ability of Mn2* to stimulate AC activity suggests that it is a function of AC catalytic subunit thaÍ is primarily impaired in pressure overload-induced cardiomegaly. Derangalent of tlp AC signaling is reflected by cardiac dysfunction. These data might be of potentiď rclevance to certain types of human congenital heart defects associarď lvith irrcreased LV pressure, such as Severe coarctation ofthe aorta or aortic stenosis Hypxia In conclusion. adaptation ofrats to IHA hypoxia led to increased localization of G"cr-L in the cytosolic fractions and it was associated with reduced bioactivity of membrane-bound Gsa protein and lower AC activity especially in RV. These changes may...