Somatosensory Nerve Fibers Mediated Generation of De-qi in Manual Acupuncture and Local Moxibustion-Like Stimuli-Modulated Gastric Motility in Rats

Abstract

The aim of this study was to reveal the somatosensory nerve fibers mediated generation of De-qi in manual acupuncture stimuli (MAS) and local moxibustion-like stimuli (LMS). The effects of strong and slight MAS, as well as 41°C, 43°C, and 45°C LMS at ST36 and CV12 on gastric motility were observed in rats. Gastric motility was continuously measured by an intrapyloric balloon, and the average amplitude, integral, and frequency of gastric motility during LMS were compared with those of background activity. Gastric motility was facilitated by MAS and LMS at ST36 and inhibited at CV12. The modulatory effects induced by strong MA with potent De-qi (needle grasp feeling) were markedly higher than those by slight MA with mild De-qi sensation (P < 0.05). The nociceptive 43°C and 45°C LMS, rather than nonnociceptive 41°C LMS, produced significant regulatory effects on gastric motility. Based on the afferent fibers activated in the present study, these results support the hypothesis that A δ - and C-afferent fibers were more likely to be involved in the generation of De-qi sensation.

Figure 1

Gastric motility in response to LMS at ST36 with different intensities in rats. (a) Examples of the alterations of gastric contraction wave induced by different intensities of LMS at ST36. (b, c, and d) The changes of the amplitude, integral, and frequency of gastric motility induced by LMS at ST36 in total 180 s, respectively (n = 9; *P < 0.05, **P < 0.01, and ***P < 0.001, versus background activities; ^## P < 0.01, as compared with the facilitatory effects in the same time course of 43°C LMS at ST36).

Figure 2

Gastric motility in response to LMS at CV12 with different intensities in rats. (a) Examples of the alterations of gastric contraction wave induced by different intensities of LMS at CV12. (b, c, and d) Changes of the amplitude, integral, and frequency of gastric motility induced by LMS at CV12 in total 180 s, respectively (n = 9; *P < 0.05, **P < 0.01, and ***P < 0.001, versus background activities; ^## P < 0.01 and ^### P < 0.001, as compared with the inhibitory effects in the same time course of 43°C LMS at CV12).

Figure 3

Gastric motility in response to MAS at ST36 with different intensities in rats. (a) Examples of the alterations of gastric contraction wave induced by different intensities of MAS at ST36. (b, c, and d) Changes of the amplitude, integral, and frequency of gastric motility induced by MAS at ST36 in 60 s, respectively (n = 9; *P < 0.05, **P < 0.01, and ***P < 0.001, versus background activities; ^# P < 0.05, as compared with the facilitatory effects of slight MAS at ST36).

Figure 4

Gastric motility in response to MAS at CV12 with different intensities in rats. (a) Examples of the alterations of gastric contraction wave induced by different intensities of MAS at CV12. (b, c, and d) Changes of the amplitude, integral, and frequency of gastric motility induced by MAS at CV12 in 60 s, respectively (n = 9; **P < 0.01 and ***P < 0.001, versus background activities; ^# P < 0.05, as compared with the inhibitory effects of slight MAS at CV12).

Figure 5

Comparison of the regulatory effects on gastric motility between the last 60 s of 45°C LMS and strong MAS. (a) Comparison of the facilitatory effects on gastric motility between the last 60 s of 45°C LMS and strong MAS at ST36. (b) Comparison of the inhibitory effects on gastric motility between the last 60 s of 45°C LMS and strong MAS at CV12 (n = 9; *P < 0.05, **P < 0.01, and ***P < 0.001).