title: Parasympathetic activation by pyridostigmine on chemoreflex sensitivity in heart-failure rats.
abstract: We evaluated the effects of parasympathetic activation by pyridostigmine (PYR) on chemoreflex sensitivity in a rat model of heart failure (HF rats). HF rats demonstrated higher pulmonary ventilation (PV), which was not affected by PYR. When HF and control rats treated or untreated with PYR were exposed to 15% O2, all groups exhibited prompt increases in respiratory frequency (RF), tidal volume (TV) and PV. When HF rats were exposed to 10% O2 they showed greater PV response which was prevented by PYR. The hypercapnia triggered by either 5% CO2 or 10% CO2 promoted greater RF and PV responses in HF rats. PYR blunted the RF response in HF rats but did not affect the PV response. In conclusion, PYR prevented increased peripheral chemoreflex sensitivity, partially blunted central chemoreflex sensitivity and did not affect basal PV in HF rats.
authors.affiliation: Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: João Paulo J
authors.initials: JP
authors.lastname: Sabino
authors.forename: Carlos Alberto Aguiar
authors.initials: CA
authors.lastname: da Silva
authors.forename: Humberto
authors.initials: H
authors.lastname: Giusti
authors.forename: Mogens Lesner
authors.initials: ML
authors.lastname: Glass
authors.forename: Helio C
authors.initials: HC
authors.lastname: Salgado
authors.forename: Rubens
authors.initials: R
authors.lastname: Fazan
mesh_terms: D000818:Animals; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D004195:Disease Models, Animal; D006333:Heart Failure / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects; D006935:Hypercapnia / Q000503:physiopathology; D000860:Hypoxia / Q000503:physiopathology; D008297:Male; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000187:drug effects; D011729:Pyridostigmine Bromide / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002800:Cholinesterase Inhibitors; D011729:Pyridostigmine Bromide
keywords: Central chemoreflex; Heart failure; Peripheral chemoreflex; Pyridostigmine