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Ventilatory control in newborn mice prenatally exposed to cocaine
Author(s) -
Autret Fanny,
Dauger Stéphane,
Renolleau Sylvain,
Eng Guy Vardon,
Kosofsky Barry E.,
Gressens Pierre,
Gaultier Claude,
Gallego Jorge
Publication year - 2002
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.10202
Subject(s) - medicine , hypoxia (environmental) , saline , hypercapnia , anesthesia , fetus , hypoxic ventilatory response , ventilation (architecture) , tidal volume , gestation , plethysmograph , respiratory system , gestational age , prenatal cocaine exposure , pregnancy , physiology , endocrinology , prenatal exposure , biology , mechanical engineering , chemistry , organic chemistry , oxygen , engineering , genetics
Abstract Infants born to mothers who used cocaine during pregnancy are at increased risk for neonatal death and respiratory impairments. Confounding factors such as multiple substance abuse make it difficult to isolate the effects of cocaine. We used a murine model to test the hypothesis that prenatal cocaine exposure may impair ventilatory responses to chemical stimuli in newborns. Seventy‐two pregnant mice were randomly assigned to three groups: cocaine (COC), saline (SAL), and untreated (UNT). COC and SAL mice received subcutaneous injections of either 20 mg/kg of cocaine or a saline solution twice a day from gestational days 8–17. Ventilation (V′ E ) and tidal volume (V T ), both divided by body weight, and breath duration (T TOT ) were measured using whole‐body plethysmography in freely moving COC (n = 47), SAL (n = 123), and UNT (n = 93) pups on postnatal day 2. The comparison between SAL and UNT pups showed significant differences in baseline breathing and in V′ E responses to hypoxia, suggesting that maternal stress caused by injections affected the development of ventilatory control in pups. Baseline T TOT was significantly longer in COC than in SAL pups. V′ E responses to hypoxia were significantly smaller in COC than in SAL pups (+27 ± 35% vs. +38 ± 25%), but V′ E responses to hypercapnia were similar (29 ± 15% vs. 25 ± 23%). Thus, breathing control was impaired by prenatal cocaine exposure, possibly because of abnormal development of neurotransmitter systems, such as the dopamine and serotonin systems. Pediatr Pulmonol. 2002; 34:434–441. © 2002 Wiley‐Liss, Inc.