Efeito do ultra-som terapêutico em ratas prenhes

Abstract

PURPOSE: to evaluate the effect of exposure of female rats to therapeutic ultrasound in the pre-implantation phase. METHODS: pregnant Wistar female rats have been exposed to 3 MHz, 0.6 W/cm2 ultrasound, pulsatile ultrasound (PUS) or continuous ultrasound (CUS), and controls, unplugged ultrasound (UUS), for five minutes. The rats were sacrificed at the 20th day post-insemination. Biochemical and hematological analyses have been done. Animals have been submitted to necropsy in order to identify lesions of internal organs, and to remove and weight the liver, kidneys and ovaries. Alive, malformed, dead and reabsorbed fetuses have been counted. RESULTS: the rats have not presented changes in their body and organs weight, and neither in their reproductive capacity, but there has been an increase in triglycerides in the PUS and CUS groups, when compared to the UUS group. The fetuses' relative weights of the heart (0.7 ± 0.9), liver (9.8 ± 0.8), kidneys (6.2 ± 0.8) and lungs (3.8 ± 0.4) increased in the CUS, when compared to the heart (0.7 ± 0.9), liver (9.8 ± 0.8), kidneys (6.2 ± 0.8) e lungs (3.8 ± 0.4) of the UUS. CONCLUSIONS: in the experimental model, the therapeutic ultrasound used has not caused meaningful maternal toxicity. Pulsatile waves have not changed fetal morphology, but continuous waves have caused increase in the relative weight of the fetuses' heart, liver, lungs and kidneys.