[Manual acupuncture stimulation of acupoints at the same and adjacent spinal segments promotes uterine contractility]

To investigate the effect of manual acupuncture stimulation of acupoints at different spinal nerve segments on uterine motility and the complicated adrenergic and cholinergic receptors.

Eighteen adult non-pregnant SD rats were used in the present study. The contractive activities of the uterus were measured by using a pressure transducer which was connected to an inserted water-filled balloon in the uterus via a PE tube at one end and an amplifier at the other end. Manual acupuncture needle was applied to "Zigong"(EX-CA1),"Huiyin" (CV1), "Xuehai "(SP10) and "Taichong "(LR3) acupoints located at the same or adjacent spinal nerve segments of the uterus, and to "Neiguan" (PC6) situated at the distant spinal nerve segment at about 2 Hz for 1 min, followed by observing changes of the uterine contractility. After acupuncture, α-adrenoceptor antagonist phentolamine (0.5 mg/kg, n=9) or cholinergic muscarinic (M) receptor antagonist atropine (0.5 mg/kg，n=9) was given to the rats of different acupoints respectively through tail vein, followed by observing changes of the uterine automatic systolic pressure difference (value of systolic pressure peak minuses the trough value) and frequency after manual acupuncture stimulation as well as after blocking the activities of α-adrenoceptors and M receptors, separately.

After acupuncture stimulation of EX-CA1, CV1, SP10 and LR3, but not PC6, the systolic pressure difference and frequency of the uterus were signi-ficantly increased (P<0.05,P<0.001, P<0.01). Following intravenous injection of phentolamine, both the systolic pressure difference and frequency had no marked changes after acupuncture at the 5 acupoints (P>0.05). After intravenous injection of atropine, the uterine systolic pressure difference and frequency were markedly decreased compared with the basic values before acupuncture stimulation (P<0.001), but had no obvious changes after acupuncture at the 5 acupoints at both the same and distant spinal segments to the uterus (P>0.05).

Manual acupuncture stimulation of acupoints at the same and adjacent spinal segments can promote the contractility of uterus in normal rats, which is realized by activating both α-adrenoceptor and cholinergic M receptors.