Revista de Farmacologia Clínica e Experimental

Abstrato

Constrictor Action of Substances in the Pulmonary Artery in Newborn with the Amnional Fluid Aspiration Syndrome (MAS)

Hilmi Islami *,Ragip Shabani ,Naim Haliti ,Gani Dragusha ,Bajram Nuraj ,Salih Ahmeti

In this in vitro work, action of acetylcholine and histamine on pulmonary artery in live and dead newborn (250 up to 3000g of body weight) which have died due to aspiration of amnional fluid was studied. Response of tracheal rings and pulmonary artery preparations on acetylcholine 10-4, 10-3, 10-2, 10-1 mol/dm3; and histamine: 10-4, 10-3, 10-2, 10-1 mol/dm3 followed up. Response of tracheal smooth musculature was registered in a multi-channel registration (Watanabe HSE 6600) Statcham. The action of acetylcholine in the pulmonary artery, in cases which has died due to aspiration of amnional fluid, has not experienced any significant change (p > 0.1), whilst histamine has caused constriction of the pulmonary artery in a significant manner (p < 0.01). Despite this, examination of tracheal rings in the controlling group with the meconial aspiration syndrome (MAS) and the group with lung atelectasis which have died from the distress respiratory syndrome (DRS), has caused significant response of tracheal smooth musculature (p < 0.01). Aim of the work was to evaluate the effect of meconium at the newborn pulmonary artery. Results suggest that meconium does not increase in a significant manner the reactivity of the smooth musculature to acetylcholine but this reactivity is expressed in histamine. Relaxation can be explained with the fact that at the syndrome of meconial aspiration exist a high content of the magnesium in the meconium which can obstructs entry of the calcium in the cell interior by causing relaxant effect.