Neuropeptide galanin, galanin-like peptide and galanin receptors 1, 2 and 3 are a crucial part of the so-called galaninergic system. Our previous studies have shown the possible role of this system in mood modulation, especially regarding stress. So far, the galanin receptors have been found in different tissues including brain and heart. Our study deals with changes in expression of galanin receptor subtypes in the heart of Wistar rats exposed to three different types of stress. Galanin receptor subtypes were determined in fluorescently labelled samples using specific primary antibodies, and all sections were analysed in an immunofluorescent microscope and microphotographs. Image analyses were subsequently performed by software ImageJ, using the threshold method with calculation of the DAPI/galanin receptor signal ratio. We found all three types of receptors in the right and left atria and left and right ventricles. Changes in the density of galanin receptors after application of the stressor depended on the observed heart compartment. We found a significant decrease of galanin receptor 1 in all compartments after all types of stress. For GalR2 and GalR3, the increase/decrease of density was dependent on the tested compartment. These results show that galanin receptors could be involved in the function of heart during the cardiac cycle.

Institute of Biophysics and Informatics 1st Faculty of Medicine Charles University Prague Czech Republic

Institute of Medical Biochemistry and Laboratory Diagnostics of Charles University the 1st Faculty of Medicine and General University Hospital Prague Czech Republic

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Effects of celastrol on the heart and liver galaninergic system expression in a mouse model of Western-type diet-induced obesity and metabolic dysfunction-associated steatotic liver disease and steatohepatitis