In hamsters dopamine D2 receptors affect ventilation during and following intermittent hypoxia.
We tested the hypothesis that in golden Syrian hamsters (Mesocricetus auratus) carotid body dopaminergic D2 receptors modulate ventilation in air, during exposure to intermittent hypoxia (IH) and reoxygenation. Ventilation was evaluated using the barometric method and CO2 production was determined using the flow through method. Hamsters (n=8) received either subcutaneous injections of vehicle, haloperidol (0.5 mg/kg) or domperidone (0.5 mg/kg). Ventilatory and metabolic variables were determined 30 min following injections, after each of 5 bouts of 5 min of 10% oxygen interspersed by normoxia (IH), and 15, 30, 45 and 60 min following IH when hamsters were exposed to air. Haloperidol, but not domperidone decreased body temperature in hamsters. Neither treatment affected CO2 production. Vehicle-treated hamsters exhibited ventilatory long-term facilitation (VLTF) following IH. Haloperidol or domperidone decreased ventilation in air, during IH and eliminated VLTF due to changes in tidal volume and not frequency of breathing. Thus, in hamsters D2 receptors are involved in control of body temperature and ventilation during and following IH.
Schlenker
Evelyn H
EH
Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, 414 East Clark St., Vermillion, SD 57069, USA. Evelyn.Schlenker@usd.edu
D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D002245:Carbon Dioxide / Q000378:metabolism; D002344:Carotid Body / Q000187:drug effects* / Q000378:metabolism; D006224:Cricetinae; D004195:Disease Models, Animal; D004294:Domperidone / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D006220:Haloperidol / Q000494:pharmacology*; D000860:Hypoxia / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008647:Mesocricetus; D012123:Pulmonary Ventilation / Q000187:drug effects*; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D013990:Tidal Volume / Q000187:drug effects; D013997:Time Factors
D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D017448:Receptors, Dopamine D2; D002245:Carbon Dioxide; D004294:Domperidone; D006220:Haloperidol