CAP formulations are now developed to treat a variety of diseases associated with neurogenic pain. The widespread use of CAP as a food additive, topical analgesic or even self defense product, necessitates an evaluation of its to icity. Numerous studies have investi gated the effect of CAP on genoto icity and mutagenicity on different cell types in vitro as http://www.selleckchem.com/products/chir-99021-ct99021-hcl.html well as in vivo. However, the results are discordant, as some studies have showed that CAP has tumour promoting potential whereas others have suggested that this compound may be useful in the prevention or treatment of cancer due to its ability to inhibit the growth of trans formed cells by inducing apoptosis. Only a few and contradictory studies have investigated the effect of CAP on the reproductive system. Nagabushan et al.

found that CAP inhibits DNA synthesis in the tes tes of adult mice when injected intraperitoneally while Muralidhara and Narasimhamurthy did not find any alteration in testicular weight and histology using similar doses. Remarkably, Ozer et al. showed that CAP stim ulates spermatogenic cell proliferation in developing roosters. Additionally these authors demonstrated that CAP accelerates the development of female reproductive organs. CAP elicits a sensation of burning pain by selectively acti vating sensory neurons that convey information about no ious stimuli to the central nervous system. An e pres sion cloning strategy was used based on calcium influ to isolate functional cDNA encoding a capsaicin receptor from sensory neurons.

This receptor is a non selective cat ion channel that is structurally related to members of the TRP family of ion channels called transient receptor potential vanilloid type 1. In summary, TRPV1 is a channel activated by CAP. The effects of CAP are medi ated through TRPV1. In order to gain more insight into the effect of CAP on spermatogenesis, we investigated the impact of this com pound on germ cells by using previously developed rat spermatogonial stem cell lines as a model. We stud ied herein the e pression of TRPV1 on the germ cells and our results indicate that CAP induces apoptosis of the immortalized cell lines in a time and dose dependent manner and that the effect may be mediated by TRPV1 which is e pressed by these cells. Methods Animals and cell lines Adult Wistar U WU male rats were obtained from the Central Animal Facilities of the University of Utrecht, The Netherlands.

All animals were killed by CO2 inhala tion. The testes were immersion fi ed in Bouins solution, paraffin embedded, sectioned and processed for immu nohistochemistry. The ethical and animal care board of the University of Utrecht approved this study. Two rat spermatogenic stem cell lines were Drug_discovery used. A rat glioma cell line was purchased from the European Collection of cell cultures.