Limits...
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 pH reduction on membrane current. Change current in response to a reduction of external pH from 7.4 to 6.2 in noninjected oocytes (open circles) and in cRNA-injected cells (filled squares). Data for injected cells are averages (±SEM) of 7 measurement; for the control cells 2 measurements were performed.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3539758&req=5

fig4: Effect of pH reduction on membrane current. Change current in response to a reduction of external pH from 7.4 to 6.2 in noninjected oocytes (open circles) and in cRNA-injected cells (filled squares). Data for injected cells are averages (±SEM) of 7 measurement; for the control cells 2 measurements were performed.

Mentions: TRPV1 can also be activated by reduced pH [12]. Over the potential range of −40 to −120 mV, reducing the extracellular pH hardly affected the membrane current in noninjected oocytes (Figure 4). In cRNA-injected oocytes, the change in pH from 7.4 to 6.2 activated a current (Figure 4) with similar voltage dependence as the capsaicin-induced current (compare Figure 1(b)).


Stimulation of TRPV1 by Green Laser Light.

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

Effect of pH reduction on membrane current. Change current in response to a reduction of external pH from 7.4 to 6.2 in noninjected oocytes (open circles) and in cRNA-injected cells (filled squares). Data for injected cells are averages (±SEM) of 7 measurement; for the control cells 2 measurements were performed.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3539758&req=5

fig4: Effect of pH reduction on membrane current. Change current in response to a reduction of external pH from 7.4 to 6.2 in noninjected oocytes (open circles) and in cRNA-injected cells (filled squares). Data for injected cells are averages (±SEM) of 7 measurement; for the control cells 2 measurements were performed.
Mentions: TRPV1 can also be activated by reduced pH [12]. Over the potential range of −40 to −120 mV, reducing the extracellular pH hardly affected the membrane current in noninjected oocytes (Figure 4). In cRNA-injected oocytes, the change in pH from 7.4 to 6.2 activated a current (Figure 4) with similar voltage dependence as the capsaicin-induced current (compare Figure 1(b)).

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