1.Analgesic effects and mechanisms of Hegu acupoint catgut embedding in a rat model of labor
Zijing ZHANG ; Minli HUANG ; Hongfei DAI ; Jiaxin LI ; Zuen LIN ; Feng SUN ; Ruiping PANG ; Lingling WU
Chinese Journal of Pathophysiology 2024;40(10):1943-1949
AIM:This study aimed to observe the analgesic effects of Hegu acupoint catgut embedding in a rat model of labor and investigate its influence on biomarkers such as calcitonin gene-related peptide(CGRP)signals at the Hegu acupoint.METHODS:Thirty-six pregnant rats were randomly divided into three groups:control group,Hegu acu-puncture group,and Hegu catgut embedding group.Pain threshold changes were assessed using the tail immersion test and paw withdrawal thermal latency at four time points:pre-induction,before the onset of labor,at the onset of labor,and at the mid-stage of labor.Tissue samples from the Hegu acupoint were collected at the mid-stage of labor to detect the ex-pression of CGRP,substance P(SP),and mast cells using immunofluorescence.The concentrations of ATP and ade-nosine were measured using ELISA.RESULTS:Before labor induction,there was no significant difference in tail immer-sion test and paw withdrawal thermal latency among the three groups(P>0.05).Before the onset of labor,both the acu-puncture and catgut embedding groups exhibited significantly higher tail-flick times and paw withdrawal latencies com-pared to the control group(P<0.05).At labor initiation and mid-labor,the catgut embedding group had significantly higher tail-flick times and paw withdrawal latencies compared to both the control and acupuncture groups(P<0.05).During mid-labor,the expression of CGRP,SP,mast cells,ATP,and adenosine concentrations in the catgut embedding group was significantly higher than that in the control and acupuncture groups(P<0.05),with co-expression of CGRP,SP,and mast cells observed.CONCLUSION:Hegu acupoint catgut embedding effectively alleviates labor pain,and its mechanism may involve increased local expression of CGRP and SP,promoting mast cell degranulation,and increasing ATP release and its conversion to adenosine.