Expression dynamics of the serotonergic system components in granulosa cells of the developing ovarian follicle and after luteinization

Regulation of the growth and development of female sex cells is one of the conservative functions of serotonin, but their specific mechanisms remain undisclosed yet. Molecular-genetic study of the presence of all components of the serotonergic system and dynamics of their expression in granulosa cells at different stages of folliculogenesis and in corpus luteum was carried out by reverse transcription with PCR and real-time PCR. Transcripts of enzymes tryptophan hydroxylase Tph1, aromatic amino acids decarboxylase Ddc and monoamine oxidase Maoa, membrane serotonin transporter Sert and vesicular monoamine transporter Vmat2, as well as serotonin receptors Htrlb, Htrld, Htr2a, Htr2b, Htr5b and Htr7 are detected in probes investigated. A quantitative study revealed that the expression of Vmat2, Htrlb, and Htr7 genes is greater in the early stages of folliculogenesis, whereas the expression of the Vmatl gene grows by the late stages of follicular development. The relative quantity of the mRNA of the Ddc, Maoa, Vmatl and Htrlb genes increases during luteinization, while the expression of the Vmat2 and Htr7 genes, on the contrary, decreases. The presence of expression of key components of the serotonergic system and its dynamics allow as to suggest that they are involved in serotonergic regulation of folliculogenesis, as well as luteinization.