[Changes of HPAA in Different Rat Models of Gan Stagnation, Pi Deficiency, Gan Stagnation Pi Defi- ciency and Interventional Effect of Chaishu Sijun Decoction].

Objective: To compare changes of hypothalamus-pituitary-adrenal axis (HPAA) in different rat models of Gan stagnation (GS), Pi deficiency (PD), Gan stagnation Pi deficiency (GSPD) syndromes, and to observe interventional effect of Chaishu Sijun Decoction (CSD, capable of soothing Gan-qi invigorating Pi) on them.

Methods: Seventy Wistar rats were divided into the normal control group (group 1), the GS group (group 2), the PD group (group 3), the GSPD group (group 4), the GS intervention group (group 5), the PD intervention group (group 6), and the GSPD intervention group (group 7) according to random digit table, 10 in each group. Rats in group 1 received no treatment. Rats in group 2 and 5 were modeled by chronic restraint method. Rats in group 3 and 6 were modeled by excess fatigue plus alimentary abstinence method. Rats in group 4 and 7 were modeled by chronic restraint, excess fatigue, and alimentary abstinence method. At the 2nd weekend of modeling, CSD at 2.86 g/kg was fed to rats in group 5, 6, and 7 by gastrogavage for 2 successive weeks. Equal volume of distilled water was given to rats in the rest 4 groups. On the 29th day, rats were killed, adrenal weight weighed, and adrenal index calculated. Levels of plasma and hypothalamus corticotropin-releasing hormone (CRH), plasma and pituitary adrenocorticotrophic hormone (ACTH), and plasma corticosterone (CORT) were determined using radioimmunity.

Results: Compared with group 1, adrenal index significantly decreased in group 2, 3, and 4 (P < 0.05). Of them, plasma and hypothalamus CRH, plasma CORT increased significantly in group 2 and 4 (P < 0.05). Besides, plasma and pituitary ACTH increased in group 4 (P < 0.05). Plasma and pituitary ACTH, as well as plasma CORT decreased significantly in group 3 (P < 0.05). Compared with group 2, 3, and 4, adrenal index increased significantly in group 5, 6, and 7 (P < 0.05). Compared with group 2, plasma CORT, hypothalamus CRH, and pituitary ACTH decreased significantly in group 5 (P < 0.05). Compared with group 3, plasma ACTH and CORT increased significantly in group 6 (P < 0.05). Compared with group 4, plasma CRH, ACTH, CORT, hypothalamus CRH, and pituitary ACTH decreased in group 7 (P < 0.05).

Conclusions: The function of HPA .axis was damaged to varying degrees in rats of the three models in this experiment. Hyperactivity of HPA axis existed in GS syndrome and GSPD syndrome. Impairment of feedback regulation in hypothalamus and pituitary was accompanied in GSPD syndrome. Hypofunction of HPA axis existed in PDS. CSD, capable of soothing Gan-qi invigorating'Pi, showed improvement on disarranged HPAA, but with optimal effect on GSPD syndrome. CSD had higher correlation with GSPD syndrome.