Pregnancy and parturition in rats after sympathetic denervation of the ovary, oviduct and utero-tubal junction

Roche, P. J.; Parkington, Helena C.; Gibson, W. P. R.

doi:10.1530/jrf.0.0750653

Cited by 9 publications

(8 citation statements)

References 22 publications

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“…A neurectomyinduced delay in the fall in systemic progesterone contrasts with reports that earlier in pregnancy, transection of the pelvic nerve, as well as the vagus nerve, was associated with reduced serum progesterone [13,48], the significance of which is uncertain because preterm birth did not occur. Nonetheless, the finding that innervation of the cervix may influence ovarian function during pregnancy could reflect efferent control by a local and more central parasympathetic pathway [49,50]. After pelvic nerve transections, there is a loss of afferent connections to local interneurons in the thoracolumbar spinal cord [14], as well as to ascending sensory pathways in the dorsal columns and autonomic intermediolateral columns of the spinal cord that project to brainstem regions, i.e., solitary nucleus and dorsal motor nucleus.…”

Section: Discussionmentioning

confidence: 99%

Transection of the Pelvic or Vagus Nerve Forestalls Ripening of the Cervix and Delays Birth in Rats1

Clyde

Lechuga

Ebner

et al. 2011

Biology of Reproduction

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Innervation of the cervix is important for normal timing of birth because transection of the pelvic nerve forestalls birth and causes dystocia. To discover whether transection of the parasympathetic innervation of the cervix affects cervical ripening in the process of parturition was the objective of the present study. Rats on Day 16 of pregnancy had the pelvic nerve (PnX) or the vagus nerve (VnX) or both pathways (PnX+VnX) transected, sham-operated (Sham) or nonpregnant rats served as controls. Sections of fixed peripartum cervix were stained for collagen or processed by immunohistochemistry to identify macrophages and nerve fibers. All Sham controls delivered by the morning of Day 22 postbreeding, while births were delayed in more than 75% of neurectomized rats by more than 12 h. Dystocia was evident in more than 25% of the PnX and PnX+VnX rats. Moreover, on prepartum Day 21, serum progesterone was increased severalfold in neurectomized versus Sham rats. Assessments of cell nuclei counts indicated that the cervix of neurectomized rats and Sham controls had become equally hypertrophied compared to the unripe cervix in nonpregnant rats. Collagen content and structure were reduced in the cervix of all pregnant rats, whether neurectomized or Shams, versus that in nonpregnant rats. Stereological analysis of cervix sections found reduced numbers of resident macrophages in prepartum PnX and PnX+VnX rats on Day 21 postbreeding, as well as in VnX rats on Day 22 postbreeding compared to that in Sham controls. Finally, nerve transections blocked the prepartum increase in innervation that occurred in Sham rats on Day 21 postbreeding. These findings indicate that parasympathetic innervation of the cervix mediates local inflammatory processes, withdrawal of progesterone in circulation, and the normal timing of birth. Therefore, pelvic and vagal nerves regulate macrophage immigration and nerve fiber density but may not be involved in final remodeling of the extracellular matrix in the prepartum cervix. These findings support the contention that immigration of immune cells and enhanced innervation are involved in processes that remodel the cervix and time parturition.

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Section: Discussionmentioning

confidence: 99%

Transection of the Pelvic or Vagus Nerve Forestalls Ripening of the Cervix and Delays Birth in Rats1

Clyde

Lechuga

Ebner

et al. 2011

Biology of Reproduction

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“…These authors (Burden & Lawrence 1977) also found that denervation on days 10, 14 and 18 of pregnancy caused a decrease in the activity of the 5-3 -hydroxysteroid dehydrogenase enzyme which synthesises progesterone. However, Roche et al (1985) who performed the denervation on day 15 observed that it did not affect the normal development of gestation. On the other hand, Massa & Bruce (1994) have reported that, on day 16 of pregnancy, the secretion of ovarian progesterone is not modified when noradrenaline is injected into the ovarian artery in spite of modifying the arterial pressure.…”

Section: Introductionmentioning

confidence: 97%

Coeliac ganglion adrenergic activity modifies ovarian progesterone during pregnancy: its inter-relationship with LH

Casais

Sosa²,

Rastrilla³

et al. 2001

Journal of Endocrinology

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Most of the fibres that constitute the superior ovarian nerve (SON) originate at the neuronal bodies of the coeliac ganglion and innervate rat ovarian stroma cells. The purpose of this work was to study the part played by innervation on ovarian release of progesterone on day 15 and at the end of pregnancy in an integrated in vitro system known as the coeliac ganglion-SON-ovary system.We also investigated, in the same system, whether there is some kind of inter-relationship between the effect of adrenergic agents and LH on progesterone release on day 15 of pregnancy.The coeliac ganglion and the ovary were incubated in separate compartments, linked by the SON. The ovary was immersed in 2 ml buffer solution (ovarian compartment) and the coeliac ganglion was immersed in 2 ml of a different buffer solution (ganglion compartment). Under these conditions, the accumulation of progesterone in the ovarian compartment medium was used as an endpoint. Conditions were standardised on day 15 of pregnancy, when the decrease in the release of ovarian progesterone caused by non-specific stimulation on the ganglion with KCl (56 mM) demonstrated the functional integrity of the system. Neural influence was evaluated by the addition of adrenergic agents at a concentration of 10 6 M to the coeliac ganglion. On day 15 of pregnancy, noradrenaline and propranolol increased progesterone release while phentolamine diminished it. The existence of ganglionic tone was assessed by analysing progesterone basal levels at different stages of pregnancy. The highest secretion of progesterone was found to take place on day 15, diminishing as pregnancy advanced. In addition, adrenergic neural participation was studied during the physiological luteolysis occurring at the end of pregnancy. Major findings were that noradrenaline increased ovarian accumulation of progesterone on day 19 and decreased it on day 20, while propranolol and phentolamine diminished progesterone release on both days. In additional studies, some neuroendocrine aspects were investigated at a peripheral level. The addition of LH only to the ovarian compartment did not affect progesterone secretion. However, when LH in the ovarian compartment was accompanied by noradrenaline, propranolol or phentolamine in the ganglion compartment, the release of progesterone decreased.It can be concluded that modifications of the neural state of the coeliac ganglion affect ovarian progesterone secretion and the physiology of pregnancy via the SON. The results may confirm that the coeliac ganglion-SONovary system provides a direct link between the autonomic nervous system and physiological events during pregnancy.

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Section: Introductionmentioning

confidence: 99%

“…The influence of the sympathetic innervation on the contractile activity of uterine smooth muscle around the time of implantation has been studied in rats (Roche et al, 1985;Legrand et al, 1987;. Surgical destruction of the ovarian nerve had no effect on either blastocyst transport or spacing (Roche et al, 1985). Injection of the a-adrenoceptor antagonists, prazosin and phenoxybenzamine, depressed electromyographical activity in the uterus of rats (Legrand et al, 1989), disrupted transport and implantation, and even spacing of foetuses did not occur (Legrand et al, 1987).…”

Section: Introductionmentioning

confidence: 99%

Response of the rat myometrium to phenylephrine in early pregnancy and the effects of 6‐hydroxydopamine

Kaulenas¹,

Parkington²,

Coleman³

1991

British J Pharmacology

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1 The contractile responses of the longitudinal and circular muscle layers of the rat uterus to the ax-adrenoceptor agonist phenylephrine were measured on days 3-6 of gestation. There was a progressive increase in sensitivity to phenylephrine in both muscle layers between days 3 and 6 of gestation. Overall, this amounted to a 13 and 9 fold increase in sensitivity in longitudinal and circular muscles, respectively. In longitudinal muscle the slope of the Hill plot was 2 on day 3 of pregnancy and was decreased to 1 thereafter. 2 The sympathetic nerve terminals innervating the smooth muscle of the uterus were destroyed by administration of 6-hydroxydopamine (2 x 50mgkg-1) 4-7 days before testing with phenylephrine. Following this treatment there was a significant increase in sensitivity to phenylephrine on day 3 in both muscle layers. After day 4, the longitudinal muscle was less sensitive to phenylephrine. 3 In the longitudinal muscle there was a progressive increase in the contractile response to maximal concentrations of phenylephrine and to high potassium (100mM) between days 3 and 6 of pregnancy. In the circular muscle the responsiveness to both phenylephrine and potassium remained unchanged between days 3 and 6 of gestation. 6-Hydroxydopamine had no effect on the maximal responses to phenylephrine or high potassium in either muscle layer. 4 In conclusion, denervation supersensitivity of uterine smooth muscle following injection of 6-hydroxydopamine is observed only on day 3 of pregnancy and appears to be replaced by subsensitivity by day 6. The decrease in the slope of the Hill plot in longitudinal muscle after day 3 may be explained by changes in events between activation of a1-adrenoceptors and contraction.

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Pregnancy and parturition in rats after sympathetic denervation of the ovary, oviduct and utero-tubal junction

Cited by 9 publications

References 22 publications

Transection of the Pelvic or Vagus Nerve Forestalls Ripening of the Cervix and Delays Birth in Rats1

Transection of the Pelvic or Vagus Nerve Forestalls Ripening of the Cervix and Delays Birth in Rats1

Coeliac ganglion adrenergic activity modifies ovarian progesterone during pregnancy: its inter-relationship with LH

Response of the rat myometrium to phenylephrine in early pregnancy and the effects of 6‐hydroxydopamine

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