ABSTRACT
Objective:
To observe the effects of
moxibustion at different times on
prostaglandin E2 (
PGE2),
prostaglandin F2α (
PGF2α) and
arginine vasopressin (AVP), in the uterine
tissues of
rats with
dysmenorrhea due to
cold-dampness retention, and to explore the differences and possible mechanisms of
moxibustion at different times in easing
pain in
dysmenorrhea due to
cold-dampness retention.
Methods:
Forty-three
female Wistar rats were randomly divided into a blank
control group (n=7), a model group (n=9), a pre-
moxibustion group (n=9), an immediate-
moxibustion group (n=9) and a pre-
moxibustion plus immediate-
moxibustion group (n=9).
Rat models of primary
dysmenorrhea due to
cold-dampness retention were established using (0±1) ℃
ice water immersion method combined with
injection of
estradiol benzoate for 10 d, followed by
injection of
oxytocin on the 11th day.
Rats in the 3 intervention groups received
moxibustion to Shenque (CV 8) and Guanyuan (CV 4), 10 min for each
acupoint, once a day.
Rats in pre-
moxibustion group were given mild
moxibustion, beginning on the 8th day during modeling, for 3 continuous days;
rats in immediate-
moxibustion group were given one
time mild
moxibustion, immediately after
injection of
oxytocin on the 11th day during modeling;
rats in pre-
moxibustion plus immediate-
moxibustion group were given mild
moxibustion, beginning on the 8th day during modeling till immediately after
injection of
oxytocin on the 11th day during modeling, for 4 continuous days. The level of
PGF2α in the
rat uterine
tissues was measured by
enzyme-linked immunosorbent assay (
ELISA), and the levels of
PGE2 and AVP in
rat uterine
tissues were measured by
radioimmunoassay.
Results:
Compared with the blank
control group, the levels of
PGF2α and AVP, the
PGF2α/
PGE2 ratio in the model group were significantly increased (P<0.01), and the
PGE2 level was significantly decreased (P<0.01) in the
rat uterine
tissues in the model group. Compared with the model group, the writhing latency was significantly prolonged, the writhing number and the total writhing score were all decreased in the pre-
moxibustion group, the immediate-
moxibustion group and the pre-
moxibustion plus immediate-
moxibustion group (all P<0.01); the levels of
PGF2α and AVP, and the
PGF2α/
PGE2 ratio were all significantly decreased (P<0.05, P<0.01), and the
PGE2 level was significantly increased (P<0.01) in the
rat uterine
tissues of the 3
treatment groups. Compared with the pre-
moxibustion group, the writhing number and the total writhing score were all decreased in the immediate-
moxibustion group and the pre-
moxibustion plus immediate-
moxibustion group (all P<0.01), the writhing latency was significantly prolonged in the pre-
moxibustion plus immediate-
moxibustion group(P<0.01); the levels of
PGF2α and
PGF2α/
PGE2 ratio were significantly decreased (P<0.05, P<0.01), and the
PGE2 level was significantly increased (P<0.01) in
rat uterine
tissues in the immediate-
moxibustion group and the pre-
moxibustion plus immediate-
moxibustion group. Compared with the immediate-
moxibustion group, the writhing latency was significantly prolonged and the writhing number was decreased (all P<0.05), and the total writhing score was decreased (P<0.01) in the pre-
moxibustion plus immediate-
moxibustion group; the
PGF2α level and the
PGF2α/
PGE2 ratio were significantly decreased (P<0.01), and the
PGE2 level was significantly increased (P<0.01) in
rat uterine
tissues in the pre-
moxibustion plus immediate-
moxibustion group.
Conclusion:
Moxibustion at different times all can produce obvious
analgesic effects on
dysmenorrhea due to
cold-dampness retention in
rats, and pre-
moxibustion plus immediate-
moxibustion ranks the top. The mechanism of this
analgesic effect may be via the
regulation of abnormal
PGF2α,
PGE2 and AVP levels, to effectively inhibit the
spastic contraction of uterine
smooth muscle in
dysmenorrhea rat, thereby improving the
ischemia and
hypoxia in
uterus.