The axons that constitute the ovarian nervous plexus originate mostly in the principal neurons of the superior mesenteric ganglion (SMG) that is part of the sympathetic ganglionic chain and exhibits cholinergic receptors. In order to observe the effect of acetylcholine, the main neurotransmitter in the ganglionic transmission, the purpose of the present work was: first, to standardize an integrated ex vivo superior mesenteric ganglion-ovarian nervous plexus-ovary (SMG-ONP-O) system in oestrus day rats; secondly, to determine if the ganglionic cholinergic stimulus modifies the release of nitric oxide and steroids in the ovary compartment in the absence of humoral factors; and thirdly, to investigate if there are differences in the responses between the left and right ovaries caused by the neural stimulus. The ex vivo experimental left and right systems were developed and standardized. The systems were incubated in Krebs–Ringer phosphate buffer in a Dubnoff metabolic shaker. The progesterone release was determined to standardize the incubation times, obtaining different responses between the left and right systems, which shows that both systems have their own autonomic tone. Non-specific stimulation with KCl in the ganglion compartment provoked different responses in terms of release of progesterone and oestradiol. Progesterone decreased in the left and right systems. However, oestradiol diminished at short times and increased at 60 and 120 min in the left ovary, whereas it increases at 30 and 60 min in the right ovary. These different responses show the sensitivity and viability of both systems. When acetylcholine was used in the ganglion compartment, the release of nitric oxide, progesterone, androstenedione and oestradiol was evaluated. The liberation of nitrite increased at 15, 30 and 60 min in the left system and decreased in the right system at 120 min. Progesterone showed a decrease in its release at 15, 30 and 120 min and androstenedione at 15 min in the left ovary compartment. In the right ovary, only progesterone decreased in relation to the control at 120 min while androstenedione did not show significant changes. Oestradiol showed an increase in the left ovary compartment at all the studied times, while in the right ovary it did not show any changes. These results indicate that the neural stimulus from the superior mesenteric ganglion through the ovarian nervous plexus is one of the factors modulating the secretory activity of the ovarian steroids and nitric oxide. The system is viable and also shows a different sensitivity of the left ovary in relation to the right one at least in this cycle stage, characterized by marked irrigation and profound structural changes in the ovary.
Adriana Vega Orozco, Zulema Sosa, Verónica Fillipa, Fabian Mohamed and Ana María Rastrilla
Florencia Figueroa, Gisela Mendoza, Darío Cardozo, Fabián Mohamed, Liliana Oliveros and Myriam Forneris
Polycystic ovarian syndrome (PCOS) is a low-grade inflammatory disease characterized by hyperandrogenism and ovarian hyperinnervation. The aim of this work is to investigate whether in vivo bilateral superior ovarian nerve (SON) section in adult rats with estradiol valerate-induced PCOS (PCO rats) affects macrophage spleen cells (MФ) and modifies the steroidogenic ability of their secretions. Culture media of MФ from PCO rats and PCO rats with SON section (PCO-SON rats) were used to stimulate in vitro intact ovaries. Compared with macrophages PCO, macrophages from PCO-SON rats released less tumor necrosis factor-α and nitric oxide, expressed lower Bax and Nfkb mRNA and showed reduced TUNEL staining. Also, in PCO rats, the SON section decreased kisspeptin and nerve growth factor mRNA expressions, without changes in Trka receptor mRNA levels. Macrophage secretions from PCO-SON rats decreased androstenedione and stimulated progesterone release in PCO ovaries, compared to macrophage secretions from PCO rats. No changes were observed in ovarian estradiol response. These findings emphasize the importance of the SON in spleen MΦ, since its manipulation leads to secondary modifications of immunological and neural mediators, which might influence ovarian steroidogenesis. In PCO ovaries, the reduction of androstenedione and the improvement of progesterone release induced by PCO-SON MΦ secretion, might be beneficial considering the hormonal anomalies characteristic of PCOS. We present functional evidence that modulation of the immune-endocrine function by peripheral sympathetic nervous system might have implications for understanding the pathophysiology of PCOS.