The Activity And Ca²⁺ Effect Of Progesterone On Primary Cultured Newborn Rabbit Sympathetic Postganglionic Neurons

Progesterone, a kind of important gonadal hormone synthesized in ovary of femaleanimals and in testicles and adrenal cortex of males, has been widely researched about itsbiology in reproductive function field. It can promote maturity of female sexual organs withsecondary sex characteristic, and maintain normal sexual and reproductive function. In recentyears, the relationship between estrogen, progesterone and the diseases of the nervous systemis increasingly important. Progesterone has been reported to play an important role inneuroprotective in all kinds of experimental models. For instance, pathogenic factors of braindysfunction, Alzheimer’s disease and protecting the primary cultured hippocampal fromeffects of ferrous sulfate and beta-amyloid toxic. In our previous research, nerve cells inCeliac Superior Mesenteric Ganglion and inferior mesenteric ganglion of goat sympatheticganglion were found progesterone receptor through immunohistochemistry SP method.Which indicated that progesterone receptor may be a network node in endocrine regulation ofprogesterone and domination of autonomic nerve for the corresponding internal organs. Butthe effects of progesterone on internal organs through these receptors are still unclear. Thisresearch adopts the immunohistochemical SP method to detect progesterone receptordistribution characteristics in newborn rabbit and adult rabbit superior cervical ganglion;After neurons adherent, then different concentrations of progesterone were added to to detectthe effects of progesterone on the neurons activity by MTT method; The dynamic change ofCa2+concentration in nerve cells was observed by confocal microscopy and fluorescencetracer with Ca2+indicator. The results were as follows:1. Using immunohistochemical SP staining method, found progesterone receptors(PR)are mainly expressed in the neurons of superior cervical ganglion in newborn rabbits andadult rabbits, indicate superior cervical ganglion have the conditions to accept theprogesterone regulation. 2. Initially established a system of newborn rabbit sympathetic neurons cultured, thesympathetic neurons are stained by neuronal specific marker (mouse anti-human beta-tubulinⅢ), Neurons and neurite show strong positive, proved the neurons cultured successfully;After rabbit anti-PR polyclonal antibody cell immunohistochemical staining, found theneurons are strong positive, glial cells and neurite are weakly positive, indicate sympatheticpostganglionic neurons is the target cells of progesterone.3. Using three different concentrations of progesterone treatment in the system ofsympathetic neurons cultured, every6h to detect cell activity, found that after6h, There wasno significant effect on OD between the experimental group and the control group; After12h,the OD of20ng/mL group is significantly increase compared with the control group, but60ng/mL and100ng/mL group had no significant effect on neurons activity; After18h, theOD of all the three experimental groups are significantly reduced compared with the controlgroup; After24h,100ng/mL group is significantly reduced compared with the control group,there was no significant effect on the other two concentrations. Indicate20ng/mL ofprogesterone can enhance the activity of the system of sympathetic neurons cultured, othergroup inhibits the system activity or not significantly affected.4. Dynamic detection Ca2+concentration change within neurons cytoplasm afterprogesterone treatment under the laser confocal microscope, found that the control group hasno significant effect on Ca2+concentration;20ng/mL and40ng/mL of progesterone canincrease Ca2+concentration,60ng/mL and80ng/mL of progesterone treatment, Ca2+concentration does not continue to increase; but when60ng/mL of progesterone treatment,found Ca2+concentration has a significant transient rise, then quickly returned to its originallevel.