Effect of fetal exposure to ultrasound on B cell development in BALB/c mice

Ultrasound is a major tool for clinical diagnosis, especially during prenatal life. Therefore, it is important that the potential bioeffects of ultrasound be determined. In this report, the effects of ultrasound on the development of B lymphocytes is studied. Pregnant BALB/c mice were exposed to intensities of ultrasound ranging from 0.1-3.0 W/cm2, receiving either a single exposure on day 11, or multiple exposures on days 14, 15, and 18 or 19 of gestation. Fetal livers were removed on day 19 of gestation whereas spleen cells were obtained from 5 and 10 day old neonates. These cell populations were analyzed for: (a) the frequency of B220+ B lineage cells; (b) the frequency of immunoglobulin-positive (Ig+) cells, and (c) the ability to proliferate in response to the B cell mitogen lipopolysaccharide (LPS). None of the tests performed revealed any substantial differences between ultrasound-exposed versus sham-treated control animals. In addition, the development of blood cell types other than B lineage cells remained unaffected by exposure to ultrasound. Therefore, exposure to ultrasound at the intensities used does not appear to hinder hemopoiesis or the normal development of B lymphocytes during fetal and early neonatal life.