Since there exist some obscurities in the expression of mRNAs and their receptors in the heart, we have investigated the gene expression (mRNA levels) of adrenoceptors (α1A-, α1B-, β1-, β2-, β3-) and muscarinic receptors (M2) and the density of receptor binding sites (α1A-, α1B-, β1-, β2-adrenoceptors, muscarinic receptors). Moreover, the heart regions consist of tissue rich in ganglion cells (that are of importance in heart neural circuits) and those virtually free of them (myocytes). Therefore, we have examined the differences in the distribution of mRNAs/receptor binding sites in the atrial samples of the heart rich in ganglion cells vs. those are virtually free of them. Binding sites and mRNAs of muscarinic receptors and α1B-adrenoceptors differ in their distribution in different heart regions. The mRNAs for β1- and β2-adrenoceptors were almost equally distributed herein, while the amount of β-adrenoceptors significantly differs in the heart regions. The α1A- and β3-adrenoceptors mRNAs were also found in all investigated heart regions, but at significantly lower level and have not shown region differences. This is a new finding, especially to β3-adrenoceptors, as they were not regularly found in each heart regions. α1B-adrenoceptors have similar distribution of their mRNAs and binding sites in some heart parts. Thus, we can conclude that there are noticeable differences in the presence of receptors in heart regions that contain ganglion cells in comparison to those are virtually free of them.
- Muscarinic receptors
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)