Objective: To compare the different effect of electroacupuncture (EA) at "Zusanli" (ST36) and "Chize" (LU5) of mother rats exposed to Nicotine during pregnancy and lactation on lung function and morphological changes in offspring rats, so as to explore the most effective acupoint for improving the development of lung in neonatal rats.
Methods: A total of 24 female pregnancy SD rats were randomly divided into 4 groups: normal control, model, EA-ST36 and EA-LU5 (n＝6 rats in each group). Rats of the normal group were treated by subcutaneous injection of normal saline, and those of the other 3 groups treated by subcutaneous injection of nicotine (1 mg•kg－1•d－1) beginning from the 6th day to about the 21st day of pregnancy (childbirth day) for nicotine exposure during pregnancy and lactation. The daily EA treatment (2 Hz /15 Hz，1 mA) was applied to bilateral ST36 and LU5 for 20 min, beginning from the 6th day of pregnancy to the 21st day (childbirth day). The lung function of the offspring rats including the peak inspiratory flow (PIF), peak expiratory flow (PEF), lung resistance (RL), exhalation resistance (RE)and lung dynamic compliance (Cdyn) was detected by using a lung function analysis system. Histopathological changes (severity of alveolarization) of the offspring rats' lung tissue were observed under microscope after H．E. stain.
Results: Compared with the normal group, the PIF, RL and RE values were significantly increased (P<0.01), and PEF and Cdyn values significantly decreased in the model group (P<0.01). The alveolar diameter in the model group was evidently increased relevant to the normal group (P<0.01). Following the intervention, modeling induced increase of PIF, RL, RE and alveolar diameter and decrease of PEF and Cdyn values in the EA-ST36 group, and the increased PIF, RL and RE levels in the EA-LU5 group were obviously suppressed relevant to the model group (P<0.01, P<0.05). Additionally, modeling induced obvious congestion and edema of the alveolar wall, alveolar deformation, rupture and fusion, and reduction of the number of the pulmonary alveoli were evidently milder in both EA-ST36 and EA-LU5 groups. No significant differences were found between the EA-ST36 and EA-LU5 groups in the abovementioned 5 indexes of pulmonary function and alveolar diameter (P>0.05)．.
Conclusion: EA of ST36 and LU5 of mother rats experiencing nicotine exposure during pregnancy and lactation can improve the lung function and morphological changes in neonatal rats, and the effect of ST36 is relatively better.
Keywords: Acupoint specificity; Electroacupuncture (EA); Lung function; Lung morphology; Neonatal rats; Nicotine exposure during pregnancy and lactation.