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Stimulation of TRPV1 by Green Laser Light.

Gu Q, Wang L, Huang F, Schwarz W - Evid Based Complement Alternat Med (2012)

Bottom Line: Activation of TRPV1 by capsaicin resulted in degranulation.Red (637 nm) as well as blue (406 nm) light neither affected membrane currents in oocytes nor did it modulate capsaicin-induced current.In conclusion, we could show that green light is effective at the cellular level to activate TRPV1.

View Article: PubMed Central - PubMed

Affiliation: Shanghai Research Center for Acupuncture and Meridians, 199 Guoshoujing Road, Shanghai 201203, China.

ABSTRACT
Low-level laser irradiation of visible light had been introduced as a medical treatment already more than 40 years ago, but its medical application still remains controversial. Laser stimulation of acupuncture points has also been introduced, and mast-cells degranulation has been suggested. Activation of TRPV ion channels may be involved in the degranulation. Here, we investigated whether TRPV1 could serve as candidate for laser-induced mast cell activation. Activation of TRPV1 by capsaicin resulted in degranulation. To investigate the effect of laser irradiation on TRPV1, we used the Xenopus oocyte as expression and model system. We show that TRPV1 can functionally be expressed in the oocyte by (a) activation by capsaicin (K(1/2) = 1.1 μM), (b) activation by temperatures exceeding 42°C, (c) activation by reduced pH (from 7.4 to 6.2), and (d) inhibition by ruthenium red. Red (637 nm) as well as blue (406 nm) light neither affected membrane currents in oocytes nor did it modulate capsaicin-induced current. In contrast, green laser light (532 nm) produced power-dependent activation of TRPV1. In conclusion, we could show that green light is effective at the cellular level to activate TRPV1. To which extend green light is of medical relevance needs further investigation.

No MeSH data available.


Related in: MedlinePlus

Effect of capsaicin application on current-voltage curves. (a) Membrane current in oocytes injected with TRPV1-cRNA. Large open circles before, filled squares during, and small open circles after application of 500 nM capsaicin. (b) Capsaicine-induced current in uninjected oocytes (open circles) and cRNA-injected oocytes (filled squares). All data are averages from 8 experiments (±SEM).
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fig1: Effect of capsaicin application on current-voltage curves. (a) Membrane current in oocytes injected with TRPV1-cRNA. Large open circles before, filled squares during, and small open circles after application of 500 nM capsaicin. (b) Capsaicine-induced current in uninjected oocytes (open circles) and cRNA-injected oocytes (filled squares). All data are averages from 8 experiments (±SEM).

Mentions: TRPV1 is known to be activated by capsaicin [12, 13]. Oocytes injected with cRNA for TRPV1 responded to application of 500 nM capsaicin with an increase in membrane current that completely disappeared after washout (Figure 1(a)). To correct for possible drift with time, capsaicin-induced current Icap was calculated according to(1)Icap=I1before−I1after2−I2,where I1 is the current in the absence of capsaicin (before or after the application of the agonist) and I2 the current in the presence. The difference current will be considered as current mediated by TRPV1 (Figure 1(b)); oocytes not injected with cRNA, never exhibited any capsaicin-sensitive current (Figure 1(b)). The current-voltage dependence is characterised by outward rectification. Oocytes not injected with cRNA exhibited no response to capsaicin.


Stimulation of TRPV1 by Green Laser Light.

Gu Q, Wang L, Huang F, Schwarz W - Evid Based Complement Alternat Med (2012)

Effect of capsaicin application on current-voltage curves. (a) Membrane current in oocytes injected with TRPV1-cRNA. Large open circles before, filled squares during, and small open circles after application of 500 nM capsaicin. (b) Capsaicine-induced current in uninjected oocytes (open circles) and cRNA-injected oocytes (filled squares). All data are averages from 8 experiments (±SEM).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3539758&req=5

fig1: Effect of capsaicin application on current-voltage curves. (a) Membrane current in oocytes injected with TRPV1-cRNA. Large open circles before, filled squares during, and small open circles after application of 500 nM capsaicin. (b) Capsaicine-induced current in uninjected oocytes (open circles) and cRNA-injected oocytes (filled squares). All data are averages from 8 experiments (±SEM).
Mentions: TRPV1 is known to be activated by capsaicin [12, 13]. Oocytes injected with cRNA for TRPV1 responded to application of 500 nM capsaicin with an increase in membrane current that completely disappeared after washout (Figure 1(a)). To correct for possible drift with time, capsaicin-induced current Icap was calculated according to(1)Icap=I1before−I1after2−I2,where I1 is the current in the absence of capsaicin (before or after the application of the agonist) and I2 the current in the presence. The difference current will be considered as current mediated by TRPV1 (Figure 1(b)); oocytes not injected with cRNA, never exhibited any capsaicin-sensitive current (Figure 1(b)). The current-voltage dependence is characterised by outward rectification. Oocytes not injected with cRNA exhibited no response to capsaicin.

Bottom Line: Activation of TRPV1 by capsaicin resulted in degranulation.Red (637 nm) as well as blue (406 nm) light neither affected membrane currents in oocytes nor did it modulate capsaicin-induced current.In conclusion, we could show that green light is effective at the cellular level to activate TRPV1.

View Article: PubMed Central - PubMed

Affiliation: Shanghai Research Center for Acupuncture and Meridians, 199 Guoshoujing Road, Shanghai 201203, China.

ABSTRACT
Low-level laser irradiation of visible light had been introduced as a medical treatment already more than 40 years ago, but its medical application still remains controversial. Laser stimulation of acupuncture points has also been introduced, and mast-cells degranulation has been suggested. Activation of TRPV ion channels may be involved in the degranulation. Here, we investigated whether TRPV1 could serve as candidate for laser-induced mast cell activation. Activation of TRPV1 by capsaicin resulted in degranulation. To investigate the effect of laser irradiation on TRPV1, we used the Xenopus oocyte as expression and model system. We show that TRPV1 can functionally be expressed in the oocyte by (a) activation by capsaicin (K(1/2) = 1.1 μM), (b) activation by temperatures exceeding 42°C, (c) activation by reduced pH (from 7.4 to 6.2), and (d) inhibition by ruthenium red. Red (637 nm) as well as blue (406 nm) light neither affected membrane currents in oocytes nor did it modulate capsaicin-induced current. In contrast, green laser light (532 nm) produced power-dependent activation of TRPV1. In conclusion, we could show that green light is effective at the cellular level to activate TRPV1. To which extend green light is of medical relevance needs further investigation.

No MeSH data available.


Related in: MedlinePlus