The relationship between skin color, delayed erythema, and delayed tanning (DT) elicited by a single exposure of UVB was investigated. Both constitutive and facultative pigmentation were determined by skin reflectance using a melanometer. Skin reflectance using visible light was well correlated to the minimal immediate pigment darkening dose elicited by UVA irradiation, which may relate to epidermal melanin content, a determinant of skin color. Minimal erythemal dose (MED) was well correlated to skin color, but there was less correlation between minimal melanogenic dose and skin color or the MED, since melanogenesis is controlled by genetic factors. DT also correlated to the dose of UVB in terms of MED. A coefficient of the regression line of DT may suggest the tanning capacity of skin. The possibility of detecting mild photosensitivity in individuals from a regression line of the MED on skin color is suggested.

In the gastrointestinal tract, interstitial cells of Cajal (ICCs) act as pacemaker cells to generate slow wave activity. Interstitial cells that resemble ICCs in the gastrointestinal tract have been identified by their morphological characteristics in the bladder. KIT is used as an identification marker of ICCs. ICCs in the bladder may be involved in signal transmission between smooth muscle bundles, from efferent nerves to smooth muscles, and from the urothelium to afferent nerves. Recent research has suggested that not only the disturbance of spontaneous contractility caused by altered detrusor ICC signal transduction between nerves and smooth muscle cells but also the disturbance of signal transduction between urothelial cells and sensory nerves via suburothelial ICC may induce overactive bladder (OAB). Recent reports have suggested that KIT is not only a detection marker of these cells, but also may play a crucial role in the control of bladder function. Research into the effect of a c-kit receptor inhibitor, imatinib mesylate, on bladder function implies that KIT-positive ICCs may be therapeutic target cells to reduce bladder overactivity and that the blockage of c-kit receptor may offer a new therapeutic strategy for OAB treatment, although further study will be needed.

Tamsulosin up-regulated α(1a) and α(1d)-adrenoceptors, suggesting that it has clinical selectivity for α(1a) and α(1d)-adrenoceptors. Up-regulation of α(1)-adrenoceptors subtype expression is considered an adaptive response to chronic tamsulosin administration. The difference in the response to α(1)-adrenoceptors antagonists among patients may contribute to the diversity in the long-term efficiency of α(1)-adrenoceptor antagonists.

To reveal the mechanism of urinary urgency evoked by cold sensation, we investigated the convergence of the primary sensory afferents of the skin and bladder. Dichotomizing afferents of L6-S1 dorsal root ganglion neurons that innervate the skin and bladder was constantly observed with retrograde neuron tracers in rats. In-situ hybridization revealed that approximately 8.0% of the double-labelled cells expressed transient receptor potential channel melastatin member 8 (TRPM8) transcripts in the dorsal root ganglions. Cold and menthol stimuli to the skin generated bladder nerve responses conducted through dichotomizing axons, which significantly decreased in the presence of the TRPM8 blocker BCTC. Taken together, TRPM8-expressing sensory neurons with dichotomizing axons projecting to the skin and bladder may be responsible for the urinary urgency evoked by cold sensation.