Naloxone stimulates oxygen consumption but not ventilation in hypothyroid hamsters.
Male golden Syrian hamsters made hypothyroid by 5 wk of propylthiouracil (PTU) treatment and control hamsters given tap water were studied. Both groups of nine animals demonstrated increased oxygen consumption after SC naloxone administration relative to saline treatment. Naloxone stimulated ventilation and ventilation in response to hypoxic (10% O2) and hyperoxic, hypercapnic (7% CO2 in oxygen) challenges in control hamsters. Relative to their responses to saline, PTU-treated hamsters exhibited no stimulation of ventilation nor of ventilation in response to the gas challenges after naloxone treatment. These results suggest that (a) the stimulation of oxygen consumption by naloxone does not directly increase ventilation; and (b) thyroid hormone status in the hamster affects opioid modulation of ventilation.
Schlenker
E H
EH
Department of Physiology & Pharmacology, University of South Dakota School of Medicine, Vermillion 57069.
Means
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R
Burbach
J A
JA
D000818:Animals; D002245:Carbon Dioxide / Q000502:physiology; D006224:Cricetinae; D007037:Hypothyroidism / Q000139:chemically induced / Q000503:physiopathology*; D007279:Injections, Subcutaneous; D008297:Male; D008647:Mesocricetus; D009270:Naloxone / Q000494:pharmacology*; D010100:Oxygen / Q000502:physiology*; D011441:Propylthiouracil; D011957:Receptors, Opioid / Q000187:drug effects / Q000502:physiology; D012119:Respiration / Q000187:drug effects / Q000502:physiology; D013963:Thyroid Hormones / Q000502:physiology
D011957:Receptors, Opioid; D013963:Thyroid Hormones; D002245:Carbon Dioxide; D009270:Naloxone; D011441:Propylthiouracil; D010100:Oxygen