The effect of prenatal nicotine exposure on biphasic hypoxic ...

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Constance Kaufman Pediatric Pulmonary Research Laboratory, Department ..... Mitchell EA, Ford RP, Stewart AW, Taylor BJ, Becroft DM, Thompson JM, Scragg.
Articles in PresS. J Appl Physiol (January 29, 2004). 10.1152/japplphysiol.00935.2003

The effect of prenatal nicotine exposure on biphasic hypoxic ventilatory response and protein kinase C (PKC) expression in caudal brainstem of developing rats

Narong Simakajornboon, Vukmir Vlasic, Hong Li, Hemant Sawnani Constance Kaufman Pediatric Pulmonary Research Laboratory, Department of Pediatrics, Tulane University School of Medicine, New Orleans, Louisiana, USA

Running title: Prenatal nicotine and HVR and PKC

Correspondence:

Narong Simakajornboon, MD. Tulane University School of Medicine 1430 Tulane Ave., Dept. of Pediatrics, SL-37 New Orleans, Louisiana, USA. Tel...504-588-5601 Fax...504-584-2506 E-mail [email protected]

Copyright (c) 2004 by the American Physiological Society.

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Abstract Current evidence suggests that maternal smoking is associated with decreased respiratory drive and blunted hypoxic ventilatory response (HVR) in the newborn. The effect of prenatal nicotine exposure on overall changes in HVR has been studied; however, there is limited data on the effect of nicotine exposure on each component of biphasic HVR. To examine this issue, 5day timed pregnant Sprague-Dawley rats underwent surgical implantation of an osmotic minipump containing either normal saline (Con) or a solution of nicotine tartrate (Nic) to continuously deliver free nicotine at 6 mg /kg of maternal weight/day. Rat pups at postnatal day 5(P5), 10(P10), 15(P15) and 20(P20) underwent hypoxic challenges with 10% O2 for 20 minutes using whole body plethysmography. At P5, Nic was associated with attenuation of peak HVR; peak VE increased 44.0±6.8 % [SE] from baseline in Nic pups while that of Con pups increased 62.9± 5.1 % (P