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Central cholinergic signal-mediated neuroendocrine regulation of vasopressin and oxytocin in ovine fetuses.

Shi L, Mao C, Zeng F, Zhang Y, Xu Z - BMC Dev. Biol. (2008)

Bottom Line: I.c.v. carbachol significantly increased fetal plasma AVP and OT concentrations.The results indicate that the central cholinergic mechanism is established and functional in the regulation of the hypothalamic neuropeptides during the final trimester of pregnancy.This provides evidence for a functional link between the development of central cholinergic mechanisms and hypothalamic neuropeptide systems in the fetus.

View Article: PubMed Central - HTML - PubMed

Affiliation: Perinatal Biology Center, Soochow University School of Medicine, Suzhou 215007, PR China. lshi@llu.edu

ABSTRACT

Background: The hypothalamic-neurohypophysial system plays a fundamental role in the maintenance of body fluid homeostasis by secreting arginine vasopressin (AVP) and oxytocin (OT) in response to a variety of signals, including osmotic and nonosmotic stimuli. It is well established that central cholinergic mechanisms are critical in the regulation of cardiovascular responses and maintenance of body fluid homeostasis in adults. Our recent study demonstrated that intracerebroventricular (i.c.v.) injection of carbachol elicited an increase of blood pressure in the near-term ovine fetuses. However, in utero development of brain cholinergic mechanisms in the regulation of the hypothalamic neuropeptides is largely unknown. This study investigated AVP and OT neural activation in the fetal hypothalamus induced by central carbachol.

Results: Chronically prepared near-term ovine fetuses (0.9 gestation) received an i.c.v. carbachol (3 microg/kg). Fetal blood samples were collected for AVP and OT assay, and brains were used for c-fos mapping studies. I.c.v. carbachol significantly increased fetal plasma AVP and OT concentrations. Intense FOS immunoreactivity (FOS-ir) was observed in the fetal supraoptic nuclei (SON) and paraventricular nuclei (PVN) in the hypothalamus. Double labeling demonstrated that a number of AVP- and OT-containing neurons in the fetal SON and PVN were expressing c-fos in response to central carbachol.

Conclusion: The results indicate that the central cholinergic mechanism is established and functional in the regulation of the hypothalamic neuropeptides during the final trimester of pregnancy. This provides evidence for a functional link between the development of central cholinergic mechanisms and hypothalamic neuropeptide systems in the fetus.

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FOS-ir induced by i.c.v. carbachol in the fetal SON and PVN. SON (upper panel) and PVN (bottom panel). A and C: the animal treated with i.c.v. vehicle; B and D: the animal injected with i.c.v. carbachol (3 μg/kg). 3V: the third ventricle. Scale bar = 200 μm.
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Figure 4: FOS-ir induced by i.c.v. carbachol in the fetal SON and PVN. SON (upper panel) and PVN (bottom panel). A and C: the animal treated with i.c.v. vehicle; B and D: the animal injected with i.c.v. carbachol (3 μg/kg). 3V: the third ventricle. Scale bar = 200 μm.

Mentions: In the control fetuses, there was no or few FOS-ir in the basal forebrain structures. However, i.c.v. carbachol produced intense FOS-ir in the fetal forebrain, including the SON and PVN in the hypothalamus (Figure 3 and 4). There was a significant difference of FOS-ir in the SON and PVN between the i.c.v. vehicle and the i.c.v. carbachol injected fetuses (t = 11.2 and 8.9, respectively, both P < 0.01).


Central cholinergic signal-mediated neuroendocrine regulation of vasopressin and oxytocin in ovine fetuses.

Shi L, Mao C, Zeng F, Zhang Y, Xu Z - BMC Dev. Biol. (2008)

FOS-ir induced by i.c.v. carbachol in the fetal SON and PVN. SON (upper panel) and PVN (bottom panel). A and C: the animal treated with i.c.v. vehicle; B and D: the animal injected with i.c.v. carbachol (3 μg/kg). 3V: the third ventricle. Scale bar = 200 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2570685&req=5

Figure 4: FOS-ir induced by i.c.v. carbachol in the fetal SON and PVN. SON (upper panel) and PVN (bottom panel). A and C: the animal treated with i.c.v. vehicle; B and D: the animal injected with i.c.v. carbachol (3 μg/kg). 3V: the third ventricle. Scale bar = 200 μm.
Mentions: In the control fetuses, there was no or few FOS-ir in the basal forebrain structures. However, i.c.v. carbachol produced intense FOS-ir in the fetal forebrain, including the SON and PVN in the hypothalamus (Figure 3 and 4). There was a significant difference of FOS-ir in the SON and PVN between the i.c.v. vehicle and the i.c.v. carbachol injected fetuses (t = 11.2 and 8.9, respectively, both P < 0.01).

Bottom Line: I.c.v. carbachol significantly increased fetal plasma AVP and OT concentrations.The results indicate that the central cholinergic mechanism is established and functional in the regulation of the hypothalamic neuropeptides during the final trimester of pregnancy.This provides evidence for a functional link between the development of central cholinergic mechanisms and hypothalamic neuropeptide systems in the fetus.

View Article: PubMed Central - HTML - PubMed

Affiliation: Perinatal Biology Center, Soochow University School of Medicine, Suzhou 215007, PR China. lshi@llu.edu

ABSTRACT

Background: The hypothalamic-neurohypophysial system plays a fundamental role in the maintenance of body fluid homeostasis by secreting arginine vasopressin (AVP) and oxytocin (OT) in response to a variety of signals, including osmotic and nonosmotic stimuli. It is well established that central cholinergic mechanisms are critical in the regulation of cardiovascular responses and maintenance of body fluid homeostasis in adults. Our recent study demonstrated that intracerebroventricular (i.c.v.) injection of carbachol elicited an increase of blood pressure in the near-term ovine fetuses. However, in utero development of brain cholinergic mechanisms in the regulation of the hypothalamic neuropeptides is largely unknown. This study investigated AVP and OT neural activation in the fetal hypothalamus induced by central carbachol.

Results: Chronically prepared near-term ovine fetuses (0.9 gestation) received an i.c.v. carbachol (3 microg/kg). Fetal blood samples were collected for AVP and OT assay, and brains were used for c-fos mapping studies. I.c.v. carbachol significantly increased fetal plasma AVP and OT concentrations. Intense FOS immunoreactivity (FOS-ir) was observed in the fetal supraoptic nuclei (SON) and paraventricular nuclei (PVN) in the hypothalamus. Double labeling demonstrated that a number of AVP- and OT-containing neurons in the fetal SON and PVN were expressing c-fos in response to central carbachol.

Conclusion: The results indicate that the central cholinergic mechanism is established and functional in the regulation of the hypothalamic neuropeptides during the final trimester of pregnancy. This provides evidence for a functional link between the development of central cholinergic mechanisms and hypothalamic neuropeptide systems in the fetus.

Show MeSH