Crotamiton is an anti-itch reagent that has been used for a long period.  It is contained in many ointments and skin creams.  However, mechanism for inhibition itch by crotamiton is unknown.  Recent reports show TRP channels, which are sensor for heat, cold and chemical, have role for itch transduction.  Therefore, we investigated crotamiton effect to TRP channels.  As a result, we found TRPV4, which is a sensor for warmth, is a target molecule of crotamiton.  Furthermore, Crotamiton inhibited itch-related behavior by TRPV4 activator injection in mice. 

  These results suggest that crotamiton reduces itch by TRPV4 inhibition.  Meanwhile, we found crotamiton washout induces large washout-current.  We revealed that TRPV4 pore size is increased when crotamiton washout.  The physiological functions of pore size increase are still unclear.  However, our results suggest that TRPV4 pore size can be increased in specific condition.  We revealed the mechanism for inhibition itch by crotamiton and TRPV4 pore size increase in crotamiton washout condition.

  We believe these findings are useful for improvement of anti-itch reagent.

 

Collaborative Researchers

Yamanoi Yu: Research Laboratory, Ikedamohando Co., Ltd.

Funding

This work was supported by the Japanese Ministry of Education, Culture, Sports, Science and Technology Grants 16K21691(to H. K.), 15H02501 (to M. T.), and 15H05928 (to M. T.).