Reflex cardiopulmonary responses by stimulation to type J receptors in rats exposed to NO2.
To examine the role of the vagal pathway on the cardiopulmonary functions in NO2-exposed rats, phenyl diguanide, which stimulates type J receptors in the lungs, was injected to control and exposed rats at a constant dose. Based on a statistical test, a decrease in the heart rate (HR) after the injection was observed in the groups exposed to 20 ppm NO2 for 1.5 h and 3h, and 10 ppm for 24 h. On the other hand, an increase in respiratory rate (RR) was observed in the groups exposed to 10 ppm for 3 h and 4 ppm for 1 wk. No change in HR and RR was found in the group exposed to 0.4 ppm for 4 wk. These results suggest that the augmentation of the reflex cardiopulmonary responses due to stimulation to the type J receptors was produced by exposures with a higher concentration of NO2.
D000818:Animals; D001645:Biguanides / Q000494:pharmacology; D004562:Electrocardiography; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009585:Nitrogen Dioxide / Q000633:toxicity*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012018:Reflex / Q000187:drug effects*; D012119:Respiration / Q000187:drug effects*; D011984:Sensory Receptor Cells / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology*
D001645:Biguanides; D009585:Nitrogen Dioxide; C008846:phenyl biguanide