OBJECTIVETo explore the different effects of reinforcing and reducing methods by twirling and rotating the needle on stress-induced hypertension and its mechanism.

METHODSSixty male Wistar rats were randomly divided into a nomal group (group A), a model group (group B), an acupuncture control group (group C), an acupuncture with reinforcing method group (group D)and an acupuncture with reducing method group (group E), 12 rats in each group. The model of stress-induced hypertension was established by foot-shock and noise stimulation in the other groups except group A. Group C was treated by acupuncture at left "Taichong" (LR 3) with no manipulation, group D with twirling reinforcement method and group E with twirling reducing method at the same acupoint, respectively, and group A and B with no acupuncture treatment. The contents of calcitonin gene-related peptide (CGRP) and nitrogen monoxidum (NO) in blood plasma and hypothalamus after 7 days were observed.

RESULTSAfter acupuncture treatment, the contents of CGRP in blood plasma and hypothalamus were (375.9 +/- 36.5) pg/mL and (213.6 +/- 50.1) pg/mg in group A, which were higher than (261.0 +/- 20.1) pg/mL and (156.0 +/- 21.8) pg/mg in group B , and (255.3 +/- 33.6) pg/mL and (154.3 +/- 47.3) pg/mg in group C (all P < 0.05), and (465.9 +/- 53.2) pg/mL and (250.74 +/- 47.7) pg/mg in group E higher than those in group C and (283.3 +/- 29.8) pg/mL and (164.6 +/- 47.4) pg/mg in group D (all P < 0.05), and there was no significant difference among group B, C and D (all P > 0.05). After acupuncture treatment, the contents of NO in blood plasma and hypothalamus were (43.7 +/- 5.5) micromol/L and (23.3 +/- 2.9) micromol/g in group B, (46.5 +/- 6.4) micromol/L and (23.1 +/- 3.3) micromol/g in group C, (45.8 +/- 6.7) micromol/L and (25.0 +/- 2.7) micromol/g in group D, which were all lower than (64.5 +/- 9.9) micromol/L and (30.7 +/- 1.6) micromol/g in group A (all P < 0.05), (55.9 +/- 4.6) micromol/L and (30.4 +/- 2.1) micromol/g in group E higher than those in group C and group D (all P < 0.05), and there was no significant difference among group B, C and D either (all P > 0.05).

CONCLUSIONAcupuncture with twirling reducing method can increase the contents of CGRP and NO in rats with stress-induced hypertension, thereby causing a fall in blood pressure, however, no significant influence with twirling reinforcing method. Reinforcing or reducing method by twirling and rotating the needle has different efficacy.