Dose dependent effect of progesterone on hypoxic ventilatory response in newborn rats.
The effect of progesterone as a respiratory stimulant in newborn subjects is less known than that in adults. This study investigated the dose-response curve (0, 2, 4, and 8 mg/kg, ip) of progesterone on ventilation in non-anesthetized newborn rats at 4- and 12-days old using plethysmography. Progesterone had no effects in the regulation of normoxic ventilation. However, it enhanced the response to moderate hypoxia (FiO(2) 12%, 20 min) in 4- but not in 12-days old pups. This response was similar between the dose of 4 and 8 mg/kg. These observations suggested that progesterone enhances in age- and dose-dependent manner the hypoxic ventilatory response in newborn rats.
Département de Pédiatrie, Université Laval, Québec, Canada.
Oubeidallah
O
Hichri
Jean-C
JC
Laurin
Cécile A
CA
Julien
Vincent
V
Joseph
Aida
A
Bairam
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D004305:Dose-Response Relationship, Drug; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000187:drug effects*
D011374:Progesterone