Prenatal nicotine alters maturation of breathing and neural circuits regulating respiratory control.
While perinatal nicotine effects on ventilation have been widely investigated, the prenatal impact of nicotine treatment during gestation on both breathing and neural circuits involved in respiratory control remains unknown. We examined the effects of nicotine, from embryonic day 5 (E5) to E20, on baseline ventilation, the two hypoxic ventilatory response components and in vivo tyrosine hydroxylase (TH) activity in carotid bodies and brainstem areas, assessed at postnatal day 7 (P7), P11 and P21. In pups prenatally exposed to nicotine, baseline ventilation and hypoxic ventilatory response were increased at P7 (+48%) and P11 (+46%), with increased tidal volume (p<0.05). Hypoxia blunted frequency response at P7 and revealed unstable ventilation at P11. In carotid bodies, TH activity increased by 20% at P7 and decreased by 48% at P11 (p<0.05). In most brainstem areas it was reduced by 20-33% until P11. Changes were resolved by P21. Prenatal nicotine led to postnatal ventilatory sequelae, partly resulting from impaired maturation of peripheral chemoreceptors and brainstem integrative sites.
Mahlière
Sophie
S
Université de Lyon, Lyon, France.
Perrin
David
D
Peyronnet
Julie
J
Boussouar
Aurélien
A
Annat
Guy
G
Viale
Jean-Paul
JP
Pequignot
Jacqueline
J
Pequignot
Jean-Marc
JM
Dalmaz
Yvette
Y
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001923:Brain Chemistry / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D004622:Embryo, Mammalian; D005260:Female; D000860:Hypoxia / Q000503:physiopathology; D007980:Levodopa / Q000378:metabolism; D008297:Male; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000187:drug effects*; D012137:Respiratory System / Q000187:drug effects / Q000196:embryology / Q000254:growth & development; D013990:Tidal Volume / Q000187:drug effects / Q000502:physiology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D018722:Nicotinic Agonists; D007980:Levodopa; D009538:Nicotine; D014446:Tyrosine 3-Monooxygenase