Pregnancy in rats is modulated by ganglionic cholinergic action

Abstract

The control of ovarian steroidogenesis during pregnancy is mainly of endocrine origin. At present, there is little information about the influence of neural factors on the gestation physiology. The purpose of this work was to study the action of cholinergic agents in celiac ganglion upon the liberation of progesterone and ovarian androstenedione in the second half of pregnancy in rats. We used the ex vivo celiac ganglion-superior ovarian nerve-ovary integrated system (celiac ganglion-SON-ovary) that was incubated in buffer solution for 180 min, with the celiac ganglion and the ovary located in different compartments and linked by the SON.The results obtained indicate that the control values of ovarian androstenedione vary according to the pregnancy day analyzed. The addition of acetylcholine in ganglion decreased the liberation of both steroids on Day 15 whereas at the end of pregnancy it decreased the liberation of androstenedione without modifying progesterone. Due to the effect observed with atropine and hexametonium, acetylcholine action might occur through unspecific ganglionic pathways (Days 15 and 21) or through muscarinic ganglionic receptors (Days 19 and 20). Thus, we conclude that the cholinergic sympathetic system from the celiac ganglion might be a fine modulator of the pregnancy physiology.

The celiac ganglion modulates LH-induced inhibition of androstenedione release in late pregnant rat ovaries

“…The levels of androstenedione accumulated in the ovarian compartment under basal conditions in the present studies were similar to those obtained previously in our laboratory [20]. The addition of the adrenergic agonist noradrenaline (NA; 10 -6 M) to the celiac ganglion led to significant changes in the amount of androstenedione accumulated in the ovarian compartment (Figure 2).…”

“…More recently, we have also shown that modifications in the cholinergic input at the celiac ganglion also led, via the superior ovarian nerve, to modifications in ovarian steroidogenesis [20]. Adding a level of complexity to the understanding of the neuroendocrine interactions between the celiac ganglion and the physiology of the ovary we showed that modifications in the hormonal environment that surrounds the celiac ganglion affects its behavior, ultimately affecting ovarian steroidogenesis [2,21].…”

Androstenedione acts on the coeliac ganglion and modulates luteal function via the superior ovarian nerve in the postpartum rat

“…The accumulation of progesterone in the ovarian compartment of day 4 postpartum, non-lactating animals that were stimulated with androstenedione in the ganglion compartment reached values that could be observed in untreated ovaries obtained from day 21 of pregnancy [6,15], and without modifying 3␤-HSD and 20␣-HSD enzyme activities or mRNA expression. This suggests that the regressing corpora lutea of pregnancy present in postpartum ovaries are still capable of functioning if timely stimulated, in this case through a neural stimulus.…”

“…We have provided evidence that systemic administration of androstenedione or its addition to the ganglion compartment of the CG-SON-ovary system, opposes to the functional regression of the corpora lutea at the end of pregnancy in rats [14][15][16]. We further demonstrated that androgen receptor immunoreactive proteins are present in the neurons of the CG before parturition, suggesting that the indirect luteotropic activity of androstenedione may be mediated by these receptors and that they can eventually modulate the synthesis of neurotransmitters by the SON [6].…”

“…Our laboratory has demonstrated that in addition to the mainstream hormonal regulators such as oestradiol and prolactin, the physiology of the rat corpus luteum of pregnancy is modulated by the peripheral nervous system [6,[14][15][16][17].…”