Decrease of atrial natriuretic peptide content in rat superior cervical sympathetic ganglion after denervation and...

Area of Science:

• Neuroscience
• Physiology
• Biochemistry

Background:

• Atrial natriuretic peptide (ANP) is a known regulator of body fluid volume and blood pressure.
• The presence and function of ANP within the superior cervical sympathetic ganglion (SCG) are not well understood.

Purpose of the Study:

• To investigate the presence and localization of ANP in the rat SCG.
• To explore the physiological changes and potential roles of ANP within the SCG.

Main Methods:

• Radioimmunoassay and reverse-phase High-Performance Liquid Chromatography (HPLC) were used to quantify ANP.
• Experiments involved analyzing ANP levels in rats of different ages and after various surgical interventions (denervation, axotomy, enucleation, sialoadenectomy).

Main Results:

• Considerable quantities of ANP were detected in the rat SCG.
• ANP levels increased with age, reaching adult levels by maturity.
• Denervation led to a rapid and significant reduction in SCG ANP content.
• The reduction kinetics of ANP after denervation were faster than choline acetyltransferase activity, suggesting a role in cholinergic transmission.
• Axotomy, enucleation, and sialoadenectomy also reduced ANP content, indicating retrograde transport from extraganglionic organs.

Conclusions:

• ANP is present in the rat SCG and its levels are influenced by age and sympathetic innervation.
• ANP may play a role in cholinergic synaptic transmission within the SCG.
• A portion of SCG ANP is transported via retrograde axoplasmic flow from innervated extraganglionic tissues.