Electrophysiological Effects of Tachykinin Agonists on Sympathetic Ganglia of Spontaneously Hypertensive Rats
Document Type
Article
Publication Date
4-18-2002
Description
This study investigated the cellular basis for the enhanced ganglionic responsiveness to NK1 agonists in the spontaneously hypertensive rat (SHR) in comparison to their normotensive counterpart, the Wistar-Kyoto (WKY) rat. Rats for in vivo studies were anesthetized with pentobarbital and treated with chlorisondamine (10.5 μmol/kg). Extracellular recordings from the external carotid nerve showed a greater responsiveness of decentralized SHR superior cervical ganglia (SCG) to intravenous injection of SP (32 nmol/kg). Blood pressure and heart rate were increased in SHRs, whereas WKY rats responded with a decrease in blood pressure and only slight tachycardia. Membrane properties of SCG neurons, as shown by intracellular microelectrode recordings, were similar between strains. Picospritzer application of the NK1 agonist GR-73632 (100 μM, 1 s) evoked slow depolarization and increased neuron excitability. Spontaneous firing was evoked only in some neurons. Depolarization amplitudes were similar between strains; however, the NK1 agonist depolarized a greater number of neurons in hypertensive rats. In conclusion, SHRs are more responsive to ganglion stimulation by NK1 agonists due to a greater number of responsive cells within the SCG rather than an enhanced responsiveness of individual neurons.
Citation Information
Tompkins, John D.; and Hancock, John C.. 2002. Electrophysiological Effects of Tachykinin Agonists on Sympathetic Ganglia of Spontaneously Hypertensive Rats. Autonomic Neuroscience: Basic and Clinical. Vol.97(1). 26-34. https://doi.org/10.1016/S1566-0702(02)00007-3 PMID: 12036183 ISSN: 1566-0702