title: Interleukin-10 inhibits angiotensin II-induced decrease in neuronal potassium current.
abstract: Previously we demonstrated that viral-mediated increased expression of the anti-inflammatory cytokine interleukin-10 within the paraventricular nucleus of the hypothalamus significantly reduces blood pressure in normal rats made hypertensive by infusion of angiotensin II. However, the exact cellular locus of this interleukin-10 action within the paraventricular nucleus is unknown. In the present study we tested whether interleukin-10 exerts direct effects at its receptors located on hypothalamic neurons to offset the neuronal excitatory actions of angiotensin II via its type 1 receptors. The results indicated the presence of immunoreactive interleukin-10 receptors on neurons in normal rat paraventricular nucleus and that receptors for this cytokine were also expressed in neurons cultured from the hypothalamus. Patch-clamp electrophysiological recordings from these cultures revealed that extracellular application of interleukin-10 alone did not exert any alterations in neuronal membrane delayed rectifier or transient potassium currents. However, angiotensin II elicited a significant decrease in delayed rectifier potassium current, an effect that was abolished by interleukin-10 application. Since decreases in delayed rectifier potassium current contribute to increased neuronal excitability, this result is consistent with a direct inhibitory action of interleukin-10 on angiotensin-induced excitation of hypothalamic neurons. As such, these data are the first indication of a neuronal locus of action of interleukin-10 to temper the actions of angiotensin II in the hypothalamus.
authors: Department of Physiology and Functional Genomics, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA.
authors: Nan
authors: N
authors: Jiang
authors: Peng
authors: P
authors: Shi
authors: Fiona
authors: F
authors: Desland
authors: M Cristina
authors: MC
authors: Kitchen-Pareja
authors: Colin
authors: C
authors: Sumners
mesh_terms: D000804:Angiotensin II / Q000502:physiology*; D000818:Animals; D002478:Cells, Cultured; D007031:Hypothalamus / Q000502:physiology; D016753:Interleukin-10 / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D009474:Neurons / Q000378:metabolism* / Q000502:physiology; D015221:Potassium Channels / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D053701:Receptors, Interleukin-10 / Q000819:agonists / Q000502:physiology
chemical_list: D015221:Potassium Channels; D053701:Receptors, Interleukin-10; D000804:Angiotensin II; D016753:Interleukin-10