OBJECTIVETo explore the influence of nonylphenol (NP) on the neural behavioral development of filial generation rats exposed via placenta.

METHODSOn the first day of the pregnancy, the SD rats were divided into four groups, and orally administered with NP at doses of 0, 50, 100 and 200 mg/kg on gestational day 9 approximately 15 respectively. The offspring rats of each groups were examined to observe the impact of NP on the early physiological, neurobehavioral development. The changes of filial generation body weight (from generation day 1 to 28) were measured. Brain tissues were stained with Hematoxylin-eosin and Congo red to observe with optical microscope.

RESULTSIn contrast to the control group, the early physiological markers (pinna detachment, hair growth, tooth growth and eye opening) and the early neurobehavioral development indices (surface righting, air righting, acoustic startle and visual placing) were significantly delayed in the groups of NP 200mg/kg dose (P < 0.05). The developing time of physiological markers decreased from (4.5 +/- 0.8, 5.2 +/- 0.8, 12.7 +/- 1.4, 16.0 +/- 1.7) d to (3.6 +/- 0.5, 3.6 +/- 0.5, 11.1 +/- 1.1, 12.7 +/- 1.3) d while neurobehavioral developing time decreased from (6.5 +/- 0.8, 11.3 +/- 0.5, 11.2 +/- 1.0, 20.2 +/- 1.0) d to (5.1 +/- 0.4, 8.3 +/- 0.5, 9.3 +/- 0.5, 9.3 +/- 0.5) d (P < 0.05 or P < 0.01). The body weights of filial generation rats were decreased obviously from 1 st day to 28th day. Histopathological examination displayed that hippocampal neurons had congestion and oedema in the group of 100, 200 mg/kg dose.

CONCLUSIONExposures to NP during gestation might impair the neurobehavioral development of F1 rats significantly.