Effects of SP-A addition to the porcine surfactant to treat meconium aspiration syndrome in newborn rabbits

• Grant number: 10/11151-1
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2010
• End date: June 30, 2013
• Field of knowledge: Health Sciences - Medicine - Maternal and Child Health
• Principal Investigator: João Cesar Lyra
• Grantee: João Cesar Lyra
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated researchers: Celso Moura Rebello ; Cilmery Suemi Kurokawa ; Ligia Maria Suppo de Souza Rugolo ; SASKIA MARIA WIEGERINCK FEKETE

Abstract

A number of in vitro studies have shown that the addition of SP-A improves the exogenous surfactant's function in the presence of proteins and other inhibitors substances, like meconium. Objective: To determine the effects of SP-A addition to the porcine surfactant over the pulmonary function, assessed by dynamic compliance, ventilatory pressure and the lung volumes; and over the stress oxidative production in the lung tissue. To compare, in vitro, the values of minimal surface tension in solutions of pure surfactant and surfactant plus SP-A, in the presence of meconium. Design/Methods: Human meconium (65 mg/ml, 6 ml/kg) will be administrated through tracheostomy to newborn rabbits born by c-section (30 days). Animals will be ventilated using a ventilator-pletismograph system for 30 min and dynamic compliance, ventilatory pressure and tidal volume will be recorded each 5 min. After 10 min ventilation animals will be randomized into 4 study groups according to the treatment: Control (no disease, no treatment); Meconium (no surfactant treatment), Surfactant (treatment with surfactant 100 mg/kg) and SP-A (treatment with surfactant 100 mg/kg with 5% SP-A addition). The surfactant used in this study is produced by Butantan Institute (Sao Paulo, Brazil). A PV-curve will be performed to determine the lung volumes an histological analysis will be done calculating the mean alveolar size (Lm) and the distortion index (DI). Oxidative effects will be assessed by the determination of Tbars and nitric oxide in lung tissue samples. In vitro measures of minimal surface tension will be performed using the Wilhelmy balance. Statistical analysis will be by One Way ANOVA, significance will be set at 0.05. (AU)