BRIEF ETHANOL EXPOSURE INDUCES BREATHING DEPRESSION AND A MARKED INCREASE IN APNEAS IN NEONATAL RATS

ANUNZIATA, F; MOLINA JC; MACCHIONE, AF; ABATE P; HAYMAL OB

Puerto Varas

Congreso; VIII LASBRA INTERNATIONAL MEETING; 2017

Latin American Society for Biomedical Research on Alcoholism (LASBRA)

The effects of early ethanol exposure uponneonatal respiratory plasticity have receivedprogressive attention given a multifactorialperspective related with the Sudden InfantDeath Syndrome or hypoxia-associatedsyndromes. This preclinical study wasperformed in rat neonates during the braingrowth spurt period (postnatal days 3-9)which is equivalent to the 3rd humangestational trimester. Breathing rates andapneas were examined in pups receivingvehicle or a relatively moderate ethanol doseutilizing a whole body plethysmograph.Ethanol exposure progressively exerted adetrimental effect upon breathing patterns. Atest conducted at PD 9 when pups were soberconfirmed ethanol´s detrimental effects uponrespiratory plasticity (breathing depression).Pre-exposure to the drug also resulted in ahighly disorganized respiratory responsefollowing a hypoxic event characterized byheightened apneic episodes during arecovery normoxia phase. In a 2nd testconducted at PD 9 while pups wereintoxicated and undergoing hypoxia, anattenuated hyperventilatory response wasobserved. In this test there were alsoindications that prior ethanol exposuredepressed breathing rates during hypoxiaand a recovery normoxia phase, without anincrease in apneas. These results indicate thatbrief ethanol experience significantlydisorganizes respiratory patterns. It causesrespiratory depressions during and after ahypoxic event. This breathing anomaly wasaccompanied by a marked increase in thenumber of apneas during the recoverynormoxia phase when pups were testedsober. These results indicate seriousdeleterious effects of the drug uponbreathing patterns and the emergence ofapneic episodes during a critical stage whererespiratory plasticity is being structured.