ABSTRACT
Objective: To better understand the function of mast cells in acupuncture points (acupoints) inacupuncture-induced analgesia. The author tested their sensitivity to mechanical, thermo and light stimulation.Methods: The tail flick model was applied to measure analgesia in rats, and the author determined the density of mast cells in tissue slices and their degranulation ratio before/after acupuncture. The author also applied the patch-clamp technique to investigate activation of human mast cells (HMC 1 cell line) by mechanical stress or noxious heat, and the author optically observed degranulation phenomena of mast cell in response to red laser light.Results: Manual stimulation by acupuncture at Zusanli (ST 36) of the rat resulted in analgesia and the effect was more pronounced than after stimulation of a sham point nearby the acupuncture point. A higher density of mast cells was found at Zusanli (ST 36) than at the sham point, and acupuncture caused a remarkable increase in degranulation. Pretreatment with disodinm chromoglycate (DSCG, a mast cell stabilizer) injected into Zusanli (ST 36) impaired the analgesic effect of acupuncture. In whole-cell patch-clamp, increasing hydrostatic pressure induced a current that could be inhibited by 10 ～tM of ruthenium red (RuR), an inhibitor of TRPV2. Temperatures above 50～C, which are reached during moxibustion, induced a similar RuR-sensitive current. Laser light of 640 nm (48 mW) applied to acupoints had been shown previously to be highly effective in analgesia. 20 min of light application induced pronounced degranulation in HMC 1 that could be blocked by 0.02 g/mL DSCG as well as by RuR. Conclusion: The author found that mechanical stimulation of acupoints is associated with mast cell degranulation and mast-cell degranulation can be correlated with acupuncture-induced analgesia. The author suggest that TRPV2 plays a key role in mast-ceU degranulation in response to mechanical, thermal (moxibustion) as well as laser-light stimulation forming a facilitating step in acupuncture-induced analgesia.
ABSTRACT
Obiective:To establish a new and better model to investigate the properties of mast cells that couldbe involved in acupuncture process mechanisms.Methods:Connective tissue under the conum at the area of acupuncture point Zusanli(ST 36)from rat was acutely bluntly separated with forceps and scissors。And incubated in bath solution up to several hours.Mast cells in slices of that tissue were irradiated with laser light of 650 mn,and changes in the appearance were observed under mlcroscope. In addition.patch.clamp technique in whole-cell configuration was employed to induce mechano-sensitive currents by pressure applied through the patch pipette.Results:1)A high density of mast cells embedded in the extracellular matrix was detected in the tissue slices using toluidine blue staining.The mast cells survived for up to several hours;2)Laser irradiation for 10 min(40 mW) resulted in fusion of intracellular vesicles with the plasma membrane of the mast-cell surface;3)Whole.cell currents increased when pressure gradients of-30 cm,-60 cm or-90 cm H20 were applied,the response was attenuated in the presence of 1 0 u M Ruthenium Red(a common blocker of channels 0f the vallinoid.sensitive transient receptor potential family TRPV).Conclusion:The skin tissue slice of rat Zusanli(ST 36)may be used as a model to investigate the role of mast cells in acupuncture.t he results obtained in this model support the suggestion that skin mast cells play a role In laser as well as mechanical acupuncture and TRPV channels may be involved in acupuncture effects.
ABSTRACT
Objective: α-asarone is a major effective component that can be isolated from Acorus tatarinowii Schott,a Chinese herbal medicine. Clinical investigations have shown that α-asarone has strong sedative and anti-convulsive action in the central nervous system. In recent years, several medicines containing a-asarone were applied in treatment of asthma, bronchitis, expectorant, or epilepsy. However, the underlying cellular mechanism of ct-asarone is still unknown. Here the authors considered EAAC1, the transporter for the excitatory glutamate, as a possible target. Methods: Supercritical CO2 fluid extraction and silica gel column chromatography were used to obtain ct-asarone from the rhizomes of Acorus tatarinowii Schott. Xenopus oocytes with heterologously expressed EAAC 1 were used as a model system. Rate of glutamate uptake was measured by means of isotopic tracer technique. Glutamate-induced current was recorded under two-electrode voltage clamp. 40μg/mL of ct-asarone was used for testing its effect on EAAC1 activity. Results: ct-asarone induced a slight, but still significant stimulation of rate of glutamate uptake by 15%. In contrast, EAACl-mediated current became reduced (by 30% at -100 mV). Since EAAC 1 can operate in transport and also in an ion-channel mode, the result indicates strong inhibition of the channel mode. This inhibition is voltage-dependent becoming larger at more negative potentials. Conclusion: The stimulation of glutamate uptake reduces glutamate concentration in the synaptic cleft and, hence, reduces excitatory synaptic activity. The inhibition on the ion-channel mode stabilizes the membrane potential, and therefore, also contributes to reduced excitatory activity.
ABSTRACT
Objective: To investigate the possible mechanisms in acupuncture analgesia by interaction of &opioid receptor with neurotransmitter transport proteins or the Na+-K+pump. Methods: Microinjection of respective heterologous cRNA into the Xenopus oocytes as a model system, and measurement of steady-state currents under two-electrode voltage clamp. Results: The co-expression of the δ-opioid receptor with GAT1, EAAC1 or the sodium pump resulted in reducing activity of the respective transporter. Opioid receptor activation affected transporter activity in different ways: 1) GAT1 was further inhibited; 2) EAAC1 was stimulated; 3) Na+-K+ pump activity interfered with agonist sensitivity of DOR. Pump inhibition led to higher sensitivity for DPDPE. Conclusion: GABA transporter inhibition and glutamate transporter stimulation may counteract pain sensation by affecting the neurotransmitter concentration in the synaptic cleft and, therefore, may contribute synergistically to pain suppression by acupuncture. Sodium pump inhibition by endogenous ouabain may amplify these effects. These synergistic effects may be the molecular mechanism of inhibiting pain sense and/or acupuncture analgesia.
ABSTRACT
Objective: To investigate the influence of Acorus gramineus (Soland), a crude extract, SCP01, and a purified component, SCP02, and of Rosmarinus officinalis L., X0728 on human mast cells (HMC-1 Cell Line). Methods: Current-voltage of P2X7 receptors on human mast cell membrane activated by ATP was recorded by the whole-cell patch clamp technique. Results: The current at-100 mV mediated by P2X7was inhibited by (27.6±2.0) % in the presence of 40 μg/mL SCP01 and by (29.5±2.2) % in the presence of 40 μg/mL SCP02, which was identified as α-asarone. 42 μg/mL of the commercially available α-asarone inhibited the P2X7-mediated current by (52.2±2.0) %. In contrast to SCP01 and SCP02, 40μg/mL X0728 provoked stimulation of the current by (28.6±2.8) %. All effects were voltage-independent. Conclusion: The inhibition of P2X7by α-asarone will inhibit intracellular calcium increase and this may account for the inhibition of reported excitotoxic cell death. The pharmacological function of P2X7stimulation by X0728 needs further investigation.