In vitro effects of transient receptor potential channel modulators on human tuba smooth muscle

There is relatively little data on the presence of Transient Receptor Potential (TRP) channels in human tubal tissue. Our study aimed to evaluate the contraction-relaxation responses of TRPV1 channel modulators in human tuba uterina tissue. We also aimed to investigate the presence of TRPV1 channel proteins by immunohistochemical staining with TRPV1 antibodies in tuba tissue.

Ten patients with a mean age of 37.7 years who underwent tubal ligation for sterilization were included. Tissue samples were evaluated for in vitro contractility in a tissue bath. Changes in tuba smooth muscle isometric tension were measured in mg contraction. The basal mean tension was considered as 100 and capsaicin responses in the presence or absence of antagonist were expressed as a percentage of the basal mean tension.

Concentrations of capsaicin 10^-7, 10^-6, 10^-5, and 10^-4 ​M; AMG 9810 10^-5 ​M and 3x10^-5 ​M; ruthenium red 10^-5 ​M and 3x10^-5 ​M were used. Relaxation response was obtained after cumulative capsaicin administration (maximum relaxation by 20 ​%). This relaxation was partially reversed when capsaicin was applied in the presence of AMG 9810. When capsaicin was applied in the presence of ruthenium red, a complete reversal of relaxation was observed. Immunohistochemical examination of tuba tissue using TRPV1 antibodies revealed moderate to high staining.

The presence of TRPV1 channel in human tuba tissue and its relaxant effect were demonstrated for the first time in this study.