title: Depressor effect of closed-loop chip system in spontaneously hypertensive rats.
abstract: We previously reported that a closed-loop chip system was designed to decrease arterial pressure in normal rabbits and rats. In the present study, the depressor effects of the chip system were investigated in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). The arterial pressure was recorded, sampled, operated and processed in the chip system. The chip system instantaneously controlled arterial pressure by stimulating the left aortic depressor nerve according to the feedback signals of arterial pressure. The closed-loop chip system effectively decreased mean arterial pressure (MAP) and heart rate (HR) in both SHR and WKY rats. It decreased the duration and the maximal MAP level of the pressor response evoked by either intravenous injection of phenylephrine or cutaneous nociceptive stimulation in SHR, but had no significant effect on the magnitude of the increase in MAP. Furthermore, the chip system significantly increased the baroreflex gain in SHR, but not in normal WKY rats. These results suggest that the closed-loop chip system effectively decreases the arterial pressure and increases baroreflex gain in SHR. The chip system does not abolish the arterial pressure responses to accidental pressor events, but decreases the duration and the maximal MAP level of the pressor responses.
authors.affiliation: Department of Physiology, Nanjing Medical University, Nanjing 210029, China.
authors.forename: Xing-Ya
authors.initials: XY
authors.lastname: Gao
authors.forename: Xing-Lin
authors.initials: XL
authors.lastname: Huang
authors.forename: Han-Jun
authors.initials: HJ
authors.lastname: Wang
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Zhou
authors.forename: Yao
authors.initials: Y
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D017704:Baroreflex / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D004558:Electric Stimulation / Q000379:methods*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008838:Microcomputers; D010656:Phenylephrine / Q000494:pharmacology; D010812:Physical Stimulation / Q000379:methods; D011312:Pressure; D051381:Rats; D011918:Rats, Inbred SHR / Q000502:physiology*; D011921:Rats, Inbred WKY; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D014662:Vasoconstrictor Agents; D010656:Phenylephrine