Objective To observe the effect of suspending-moxibustion stimulation of"Dazhui"(GV 14)with different quantities on the levels of nerve growth factor(NGF)

substance P(SP)

calcitonin gene-related peptide(CGRP)

neurokinin A(NKA)

neurokinin B(NKB)and phosphorylated extracellular signal-regulated kinases(pERK)in the bronchoalveolar lavage fluid(BALF)of asthma rats

so as to analyze its mechanisms underlying improving asthma.Methods Sixty male SD rats were randomly divided into six groups:blank control

model

15min-moxibustion(15min-moxi)

30min-moxi

60min-moxi and 90minmoxi(n=10rats in each group).The asthma model was established by intraperitoneal injection of suspension of egg protein

magaldrate

and inactivated Bacillus pertussis(on day 1and 8)

and inhaling the atomized ovalbumin saline(from day 15 on for 14days).Mild moxibustion was conducted at"Dazhui"(GV 14)for 15 min

30min

60 min and 90 min

respectively

once daily for7 days.The levels of NGF

SP

CGRP

NKA

NKB

and pERK in the BALF were detected by ELISA(enzyme-linked immuno sorbent assay).Results The contents of NGF

SP

CGRP

NKA

NKB and pERK in the BALF in the model group were obviously higher than those in the blank control group(P<0.01)

suggesting an apparent inflammatory reaction in rats after modeling.Following moxibustion

the levels of NGF

SP

CGRP

NKA

NKB and pERK of the four treatment groups were significantly downregulated compared with the model group(P<0.01).The effect of 30min-moxi group was obviously superior to that of 15 minmoxi group(P<0.01)

and those of 60min-moxi and 90min-moxi groups were markedly superior to those of 15min-moxi and 30min-moxi groups(P<0.01)in down-regulating NGF

SP

CGRP

NKA

NKB

and pERK levels in the BALF.No significant differences were found between the 60min-moxi and 90min-moxi groups in down-regulating NGF

SP

CGRP

NKA

NKB

and pERK levels(P>0.05).Conclusion Suspending-moxibustion stimulation of GV 14 can down-regulate the contents of NGF

SP

CGRP

NKA

NKB

and pERK levels in the BALF in asthma rats

suggesting a relief of neurogenic inflammation reaction after moxibustion.The effect of moxibustion presents a time-dependant manner and peaks at 60 min.