Neuromodulatory effect of GnRH from coeliac ganglion on luteal regression in the late pregnant rat

Interplay between nitric oxide and gonadotrophin-releasing hormone in the neuromodulation of the corpus luteum during late pregnancy in the rat

“…Herein, by using an ex-vivo CG-SON-Ovary system we studied whether blocking NO synthesis in the CG affects the release of GnRH from the CG, and the impact on the physiology of the ovary at the end of pregnancy. Previous results from our research group demonstrated that the addition of the GnRH antagonist cetrorelix (CTX) to the ganglionic compartment of the CG-SON-Ovary system increased the ganglionic GnRH levels, indicating the presence of a functional GnRH system in the CG [ 16 ]. Surprisingly, in that study we also found an increase in the levels of NO in the ganglionic compartment.…”

“…Several studies support the protective role of progesterone in the function and survival of the CL, since it can locally stimulate its own production to protect the CL from cell death [ 2 , 34 , 35 ]. By contrast, GnRH may facilitate apoptosis and CL regression [ 16 , 36 , 37 ]. The reduced apoptotic levels found in the CL in the current study are consistent with an increase in the release of progesterone and a decrease in the release of GnRH into the medium of ovarian incubation of L-NAME-treated systems in the CG.…”

“…However, it was suggested by other authors that the end of luteal functionality depends on the balance among several factors [ 1 , 48 ]. In a previous study, we provided evidence that GnRH released from in the CG might trigger neuronal signals that promote luteal regression in late pregnancy [ 16 ]. In the present study, we showed that NO affects GnRH release from the CG and the consequent impacts on the physiology of the ovary.…”

“…Using this model system, we reported that the CG is able to respond to different stimuli that modify the ovarian physiology through the SON in different reproductive states of the rat [ 10 , 12 – 15 ]. Recently, we demonstrated the presence of GnRH/GnRH-receptor system in the CG and provided evidence for the fact that GnRH from the CG may trigger neuronal signals that promote luteal regression in late pregnant rats [ 16 ]. However, to the best of our knowledge, there are no references about the relatioship between NO and GnRH affecting the function of the sympathetic ganglia.…”

Nitric oxide synthase and its function in animal reproduction: an update

“…Thus, the increase in ovarian NO levels triggered by blocking ganglionic GnRH action with CTX could contribute to the increase in ovarian progesterone release and the low apoptotic luteal cell percentage observed in the experimental group, indicating that NO production by the celiac ganglion modulates the physiology of the ovary and luteal regression during late pregnancy. However, the exact mechanism underlying NOS activity remains unclear (Morales et al, 2021;Vallcaneras et al, 2022).…”