Inhibitory effect of acupoint electrostimulation with different layers and intensities on muscular inflammatory pain and spinal WDR neuron activity. / ç©´ä½ä¸åŒå±‚æ¬¡å’Œå¼ºåº¦ç”µåˆºæ¿€ç¼“è§£è‚Œè‚‰ç‚Žæ€§ç—›åŠå¯¹è„Šé«“èƒŒè§’å¹¿åŠ¨åŠ›ç¥žç»å ƒçš„æŠ‘åˆ¶ä½œç”¨.

OBJECTIVES: To observe the analgesic effects of different levels and intensities of electrical stimulation on the local acupoints in the pain source area and their impact on wide dynamic range (WDR) neurons in the spinal dorsal horn, in order to provide a basis for selecting appropriate parameters for electroacupuncture (EA) stimulation. METHODS: Wistar rats were used in 3 parts of the experiment. Complete Freund's adjuvant was used to establish a model of inflammation-induced pain in the gastrocnemius muscle. After modeling, 6 rats were randomly selected for multi-channel extracellular electrophysiological recording of the electrical activity of WDR neurons, to determine the threshold for activating the A-component (Ta) and the C-component (Tc), which were used as the intervention intensities for skin transcutaneous electrical acupoint stimulation (TEAS) or EA. Thirty-six rats were randomly divided into normal , model , TEAS-Ta , TEAS-Tc, EA-Ta , and EA-Tc groups, with 6 rats in each group. In the pain source area , Ta or Tc intensity of TEAS or EA intervention at"Chengshan"(BL57) was performed for 30 min each time, once a day, for 3 consecutive days. A small animal pressure pain measurement instrument was used to measure the mechanical pressure pain threshold of the gastrocnemius muscle in rats, and the Von Frey filament was used to measure the mechanical pain threshold of the footpad. Thirteen rats were randomly selected to observe the immediate responsiveness of WDR neurons to Ta/Tc intensity of EA or TEAS in BL57. RESULTS: The thresholds of TEAS to activate WDR neuron A-component or C-component were (2.43±0.57) mA and (7.00±1.34) mA, respectively, while the thresholds for EA to activate muscle WDR neuron A-component or C-component were (0.72±0.34) mA and (1.58±0.35) mA, respectively. After injection of CFA into the gastrocnemius muscle, compared with the normal group both the mechanical pressure pain threshold of the gastrocnemius muscle and the mechanical pain threshold of the footpad of rats in the model group were significantly decreased (P<0.001). After TEAS-Ta, TEAS-Tc or EA-Ta intervention in the BL57, both the mechanical pressure pain threshold of the gastrocnemius muscle and the mechanical pain threshold of the footpad were significantly higher than those in the model group (P<0.05, P<0.001). Compared with the normal group, the electrical threshold for evoking WDR neuron C-component discharge was significantly decreased (P<0.001) in the model group, while increased after TEAS-Ta, TEAS-Tc, or EA-Ta intervention (P<0.01) compared with the model group. The evoked discharge frequency of muscle WDR neurons decreased significantly after immediate intervention with TEAS-Ta, TEAS-Tc, or EA-Ta (P<0.01, P<0.05). EA-Tc had no significant improvement on the evoked electrical activity of WDR neurons or pain behavior. CONCLUSIONS: TEAS-Ta, TEAS-Tc, or EA-Ta can all alleviate the local and footpad mechanical pain in rats with muscle inflammation and inhibit the responsiveness of WDR neurons, indicating that different intensities are required for analgesic effects at different levels of acupoints in the pain source area.

Acupuncture Enhances Signals at Sensitized Acupoints to Elevate Pressure Pain Threshold in Knee Osteoarthritis Patients.

OBJECTIVE: To observe the pressure pain threshold (PPT), skin conductance (SC) and blood perfusion (BP) of the sensitized acupoints in patients with knee osteoarthritis (KOA), and explore the mechanism of acupuncture at the sensitized acupoints for treating diseases. METHODS: Eleven healthy subjects and 11 unilateral KOA patients were recruited from July 2020 to March 2021 in this study. The PPT, SC and BP of control acupoints in healthy controls, and non-sensitized and sensitized acupoints in KOA patients were measured and compared between baseline and after manual acupuncture (MA) treatment. RESULTS: Before MA treatment, lower PPT was observed at the sensitized acupoints compared with non-sensitized and control acupoints (P<0.05). After MA treatment, PPT at the sensitized acupoints increased significantly in KOA patients (P<0.05). Before MA treatment, there was no statistical difference in SC and BP among control, non-sensitized and sensitized acupoints (P>0.05). Compared with the control and non-sensitized acupoints, there were significant increases of SC and BP in sensitized acupoints of KOA patients after MA treatment (P<0.05 or P<0.01). CONCLUSION: MA at sensitized acupoints could elevate PPT of KOA patients, which may be associated with the increment of SC and BP.

[Sensory and sympathetic nerves are involved in the changes of skin temperature, blood infusion and inflammatory cytokines of cutaneous tissue in the sensitized area of colitis rats].

OBJECTIVE: To investigate the changes of skin temperature, blood infusion and inflammatory cytokines of cutaneous tissue in the sensitized area of colitis model rats, as well as the relationship between sensory and sympathetic nerves and the formation of sensitized area, and to initially reveal the partial physical-chemical characteristics of the sensitized area in the colitis model rats. METHODS: Thirty-five male SD rats were randomly divided into a control group (n=10), a model group (n=18) and a guanethidine group (n=7). 5% dextran sulfate sodium (DSS) was adopted for 6-day free drinking to establish colitis model in the model group and the guanethidine group. On day 6 and 7, in the guanethidine group, guanethidine solution (30 mg/kg) was injected intraperitoneally for sympathetic block. On day 7, after injection of evans blue (EB) solution, the EB extravasation areas on the body surface were observed to investigate the distribution and physical-chemical characteristics of the sensitized area. The control area was set up, 0.5 cm away from the sensitized area, and with the same nerve segment innervation. Disease activity index (DAI) score of rats was compared between the normal group and the model group, and the morphological changes in the colon tissue were investigated with HE method. Using infrared thermal imaging technology and laser speckle flow imaging technology, skin temperature and blood infusion were determined in the sensitized area and the control area of the rats in the model group. Immunofluorescence technique was adopted to observe the expression levels of the positive nerve fibers of substance P (SP), calcitonin gene-related peptide (CGRP) and tyrosine hydroxylase (TH), and the correlation with blood vessels; as well as the expression levels of SP positive nerve fibers/tryptase+ mast cells, and tryptase+ mast cells/5-hydroxytryptamine (5-HT) in skin tissue in the sensitized area and the control area of the rats in the model group. MSD multi-level factorial method and ELISA were applied to determine the contents of pro-inflammatory and anti-inflammatory cytokines (e.g. TNF-α, IL-1ß, IL-6, IL-4 and IL-10) and anti-inflammatory substance corticosterone (CORT). RESULTS: Sensitization occurred at the T12-S1 segments of the colitis model rats, especially at L2-L5 segments. Compared with the normal group, DAI score was increased in the rats of the model group (P<0.05), and the colonic mucosal damage was obvious, with the epithelial cells disordered, even disappeared, crypt destructed, submucosal edema and a large number of inflammatory cells infiltrated. In comparison with the control area, the skin temperature and blood infusion were increased in the sensitized area of the model group (P<0.05, P<0.01); as well as the expression levels of the positive nerve fibers of SP, CGRP and TH of skin tissue (P<0.05), which was specially distributed in peripheral vessels, the expression levels of SP positive nerve fibers/tryptase+ mast cells, and tryptase+ mast cells/5-HT of the skin tissue were all expanded (P<0.05) in the sensitized area of the model group. Compared with the model group, the number of sensitized areas was reduced in the guanethidine group (P<0.05). In comparison with the control area of the model group, in the sensitized area, the contents of pro-inflammatory cytokines, e.g. TNF-α, IL-1ß and IL-6, and the anti-inflammatory substance CORT of skin tissue were all increased (P<0.05); and the contents of IL-6 and TNF-α were negatively correlated with CORT (P<0.05). CONCLUSION: The sensitized areas on the body surface of colitis rats are mainly distributed in the L2-L5 segments. Sensory and sympathetic nerves are involved in the acupoint sensitization, and the sensitized areas may have the dynamic changes in pro-inflammatory and anti-inflammatory substances.

Electroacupuncture and moxibustion-like stimulation activate the cutaneous and systemic hypothalamic-pituitary-adrenal axes in the rat.

OBJECTIVE: To determine whether electroacupuncture (EA) or moxibustion-like stimulation (MLS) can affect the cutaneous and/or systemic hypothalamic-pituitary-adrenal (HPA) axes. METHODS: Rats were divided into Control, EA, 37°C MLS and 43.5°C MLS groups. EA and MLS were performed at bilateral ST36 or LI4. The expression of corticotropin-releasing factor (CRF), adrenocorticotropic hormone (ACTH) and the glucocorticoid receptor (GR) was detected in local cutaneous tissues at the site of ST36 and LI4 by immunohistochemical staining. In addition, levels of CRF, ACTH and corticosterone (CORT) in cutaneous tissue and plasma were determined. RESULTS: Cutaneous expression of CRF, ACTH and GR significantly increased after EA at ST36, while only GR increased after 43.5°C MLS at ST36. The results of EA and MLS at LI4 were in parallel with those at ST36. In plasma, compared with the control group, the level of CORT increased after EA at ST36, while both ACTH and CORT were markedly increased after 43.5°C MLS. For LI4, plasma CRF and CORT increased after EA, while the levels of all three hormones increased following 43.5°C MLS. Notably, compared with the effect of EA, 43.5°C MLS at ST36 produced a more substantial increase in plasma CORT, and 43.5°C MLS at LI4 induced a more dramatic increase in plasma CRF and CORT. CONCLUSION: Both EA and 43.5°C MLS can activate the cutaneous and systemic HPA axes of the rat. EA tended to activate the local cutaneous HPA, while 43.5°C MLS was more likely to activate the systemic HPA axis.

[Improvement in colonic inflammatory injury in rats via activating dorsal cholinergic neurons of vagus with electroacupuncture at sensitized acupoints].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at sensitized acupoints on choline acetyltransferase positive (ChAT+) neurons in dorsal motor nucleus (DMV) of brainstem vagus in the colitis model rats and explore the mechanism of the improvement in colonic inflammatory injury in the rats. METHODS: A total of 79 male SD rats were randomized into five groups, i.e. a normal group (20 rats), a normal plus sensitized acupoint group (5 rats), a model group (34 rats), an EA-1 group (15 rats) and an EA-2 group (5 rats). In the model group and the EA groups, 5% dextran sulfate sodium (DSS) was adopted for 6-day free drinking to establish colitis model rats. By injecting Evans blue (EB) into the caudal vein in the model rats, the sensitized acupoints were determined. Afterwards, in the normal plus sensitized acupoint group, the EA-1 group and the EA-2 group, EA was exerted at the sensitized acupoints, with disperse-dense wave, 2 Hz/ 15 Hz in frequency and 2 mA in intensity, for 30 min of intervention each day. The intervention lasted for 6 days in the EA-1 group and for 1 day in both the normal plus sensitized acupoint group and the EA-2 group. On day 0, 7 and 13 of experiment, successively, the score of disease activity index (DAI), the score of colonic histological damage, as well as the changes in the mechanical paw withdrawal threshold and thermal paw withdrawal latency were evaluated in the normal group, the model group and the EA-1 group. On day 7 of experiment, using immunofluorescence staining, the activation of different lamina neurons of spinal dorsal horn and ChAT+ neurons in DMV was observed in the normal group, the normal plus sensitized acupoint group, the model group and the EA-2 group separately. RESULTS: The EB extravasating areas were distributed in the segments from T12 to S1 on the body surface of colitis model rats, mainly focusing at L2 and L5. Therefore, "Shangjuxu" (ST 37) was taken as the sensitized acupoint. Compared with the normal group on day 7 and 13 of experiment, the mechanical paw withdrawal threshold were reduced (P<0.001), DAI scores and the scores of colonic histological damage were increased (P<0.001) in the model group. Compared with the normal group on day 7 of experiment, thermal paw withdrawal latency in the model group was reduced (P<0.001). Compared with the model group on day 13 of experiment, the mechanical paw withdrawal threshold was increased (P<0.001), DAI score and the score of colonic histological damage were reduced (P<0.01, P<0.05) in the EA-1 group. Compared with the normal group, the activated numbers of the neurons in superficial laminae (Ⅰand Ⅱ) at spinal dorsal horn of L4 to L6 and ChAT+ neurons in DMV were increased in the normal plus sensitized acupoint group and the model group (P<0.05, P<0.01). Compared with the normal plus sensitized acupoint group and the model group, the activated numbers of the neurons in superficial laminae at spinal dorsal horn of L4 to L6 and ChAT+ neurons in DMV were increased in the EA-2 group (P<0.001). CONCLUSION: The segmental dominance (acupoints) from T12 to S1 on the body surface of colitis rats is sensitized. EA at sensitized acupoints effectively relieves colonic inflammatory injury, which is probably by activating superficial lamina neurons of spinal dorsal horn and ChAT+ neurons of DMV.

[Moxibustion promoted transformation of inflammatory phase to facilitate wound healing in rats with full-thickness cutaneous wounds].

OBJECTIVE: Our previous study demonstrated that moxibustion could promote skin wound healing in rats with full-thickness cutaneous wounds. The present study was designed to observe the effect of moxibustion on the levels of pro-inflammatory and anti-inflammatory cytokines, and proliferation of vascular endothelial cells, so as to explore its mechanisms underlying facilitating wound-healing. METHODS: A total of 84 adult SD male rats were randomly assigned to normal (n＝6), model(n＝39)and moxibustion(n＝39)groups. The skin wound model was established by removal of a piece of full-thickness skin from the median line of the rats' back (about 2 cm below the shoulder blade). Moxibustion was applied to the surrounding area of the focus for 25 min, once daily for 6 days. The blood samples were collected at day 1, 2, 3 and 5 after modeling for assaying serum contents of IL-1α， IL-1ß， IL-6, IL-4, IL-10, IL-13, granulocyte-colony stimulating factor (G-CSF), granulocyte macrophagecolony stimulating factor (GM-CSF, an inflammatory mediator), macrophage inhibitory protein-1α (MIP-1α) and vascular endothelial growth factor (VEGF) with liquid chip methods, and the topical wound tissues were collected after trans-cardiac perfusion with 4% paraforma-ldehyde solution for detecting the expression of CD31 proteins by using immunofluorescence staining. RESULTS: After modeling and in comparison with the model group, the contents of serum IL-1α and IL-6 at the 1st day were significantly increased (P<0.05), but notably decreased at the 3rd day after modeling in the moxibustion group (P<0.05). The contents of serum IL-1ß on day 1 and 2 were significantly higher in the moxibustion group than those of the model group (P<0.05). After moxibustion, the contents of serum IL-4 and IL-10 were significantly up-regulated on day 1 after modeling (P<0.05), and obviously down-regulated from the 3rd day on (P<0.05). The contents of serum MIP-1α on the 2nd day and serum VEGF on day 1 and 2, and wound-skin VEGF on day 5 were obviously up-regulated in the moxibustion group in comparison with the model group (P<0.05, P<0.01)．. CONCLUSION: Moxibustion promotes the inflammatory response by regulating the levels of both pro-inflammatory and anti-inflammatory cytokines in the early phase of skin wounds in rats, which may be in favor of the transformation from the inflammatory phase to the proliferation phase in advance, promoting wound healing at last.

[Moxibustion promoted wound healing in rats with full-thickness cutaneous wounds].

OBJECTIVE: To explore the effects of moxibustion intervention on wound healing in rats with full-thickness cutaneous wounds. METHODS: A total of 28 adult SD male rats were randomly assigned to model group and moxibustion group (n＝14 in each one). The skin wound model was established by removal of a piece of full-thickness skin from the median line of the rats' back (about 2 cm below the shoulder blade). Moxibustion intervention was applied to the surrounding area of the focus for 25 min, once daily for 6 days. The wound healing was observed and photographed after each moxibustion intervention. The wound tissues were harvested after transcardiac perfusion with 4% paraformaldehyde solution on the 2nd and 7thday after modeling, and stained with H．E. and Masson methods for displaying histopathological changes and collagen fiber growth status, respectively. RESULTS: After modeling, the cutaneous wound was healed gradually in both groups, and the wound area was significantly smaller from the 2nd day to the 5th day in the moxibustion group than in the model group (P<0.01, P<0.05). Correspondingly, the wound closure area was significantly bigger from the 2nd to the 5th day in the moxibustion group than in the model group (P<0.01). H．E. and Masson staining showed that the number of the inflammatory cells (monocytes, macrophages, neutrophile, etc.) and the collagen fiber area in the local wound tissue of the moxibustion group were significantly bigger than those of the model group on the 2nd day after intervention (P<0.01). After 6 sessions of moxibustion intervention, the number of fibroblasts and collagen fibers in the moxibustion group were obviously increased than that in the model group, characterized by closer arrangement of fibroblasts and collagen fibers, more and larger of the new-born blood vessels, and thicker of the scab in the wound area. CONCLUSION: Moxibustion can promote the wound healing by enhancing the growth of collagen fibers and cell proliferation in the traumatic cutaneous area in full-thickness cutaneous wound rats.

[From molecular pharmacy to electroceuticals: SPARC program and acupuncture research].

The NIH-funded "Stimulating Peripheral Activity to Relieve Conditions (SPARC)" program has been initiated in Octomber 2016, aiming at developing high resolution neural circuit maps and next generation neural modulation devices. This program has brought great stimulus to acupuncturists and acupuncture researchers both at home and abroad. Is the SPARC program a driving force or a challenge of acupuncture research? In the present study, we introduced the SPARC program and compared it with current acupuncture research. The first step of SPARC is to better map neural circuits associated with disease on the anatomical level so as to identify the best points for intervention, and to decode the neural language at these intervention points for developing a dictionary of patterns associated with health and disease states on the signaling level. Similarly, our acupuncture research also focuses on revealing the neural encoding of acupuncture stimulation and its effect on visceral function, seeking suitable stimulation parameters to regulate the abnormal visceral activity precisely. Therefore, the common point of SPARC program and acupuncture research is the scientific basis of peripheral somatic neuronal regulation, and their difference is that acupuncture regulates the visceral function through multiple neural circuits and neural feedbacks by stimulating the sensitized points or acupoints, achieving homeostasis at last. Acupuncture-induced regulation effect is limited and the therapy is safe. Whereas, "stimulating periphe-ral activity (SPA)" can regulate the visceral organs precisely but without neural feedback. Inevitably, SPA will produce tolerance or side effects. Therefore, there is still much work to be done in terms of the initiation of trigger stimulation and the feedback inhibition of target organ effects. The SPARC program is definitely a powerful force in revealing the mechanisms by which acupuncture works.