We investigated the possible participation of TRPV1 channels in retinal apoptosis and overall development. Retinas from newborn, male albino rats were treated in vitro with capsazepine, a TRPV1 antagonist. The expression of cell cycle markers was not changed after TRPV1 blockade, whereas capsazepine reduced the number of apoptotic cells throughout the retina,increased ERK1/2 and p38 phosphoryla...

Electrophysiological characterization of ion channels is useful for elucidation of channel function as well as quantitative assessment of pharmaceutical effects on ion channel conductance. We used droplet bilayers to measure ensemble ion channel currents from membrane preparations made from TRPV1-expressing HEK cells. Conductance measurements showed rectification, activation by acid and capsaic...

Ruan, Ting, You Shuei Lin, Kae-Shin Lin, and Yu Ru Kou. Mediator mechanisms involved in TRPV1 and P2X receptor-mediated, ROS-evoked bradypneic reflex in anesthetized rats. J Appl Physiol 101: 644–654, 2006. First published April 20, 2006; doi:10.1152/japplphysiol.00192.2006.—Inhalation of H2O2 is known to evoke bradypnea followed by tachypnea, which are reflexes resulting from stimulation by re...

Sex-specific differences in activity of the lower urinary tract (LUT) responding to acid irritation in mice have been revealed. This study, using continuous infusion cystometry with acetic acid (AA; pH 3.0), was conducted to examine whether the transient receptor potential vanilloid type 1 (TRPV1) channels expressed in the mouse LUT are involved in the sex difference in functional responses of ...

Vanilloid receptors (VR) integrate various painful stimuli, e.g., noxious heat, acidic pH, capsaicin, and resiniferatoxin (RTX). Although VR antagonists may be useful analgesics, the available agents capsazepine and ruthenium red lack the necessary potency and selectivity. Recently, submicromolar concentrations of the arginine-rich hexapeptide RRRRWW-NH(2) (R(4)W(2)) blocked VR-mediated ionic c...

OBJECTIVE The effects of capsaicin on sensory neurons are mediated by its interaction with a specific membrane receptor and opening of a non-selective cation channel. In the rat heart, capsaicin-sensitive nerve endings are known to be activated by oxygen radicals. We investigated the possibility that free oxygen radicals stimulate sensory nerve endings by acting upon the capsaicin receptor. M...

We have synthesized iodinated resiniferatoxin bearing a 4-hydroxy-5-iodo-3-methoxyphenylacetate ester (I-RTX) and have characterized its activity on rat and human TRPV1 (VR1) receptors, as well as in behavioral assays of nociception. In whole cell patch-clamp recordings from transfected cells the functional activity of I-RTX was determined. Currents activated by capsaicin exhibited characterist...

BACKGROUND The transient receptor potential vanilloid type 1 (TRPV1) is expressed in the cardiovascular system, and increased TRPV1 expression has been associated with cardiac hypertrophy. Nevertheless, the role of TRPV1 in the pathogenesis of cardiac hypertrophy and the underlying molecular mechanisms remain unclear. METHODS AND RESULTS In cultured cardiomyocytes, activation of TRPV1 increas...

INTRODUCTION There is increasing evidence that retinal pigment epithelium (RPE) can be used to treat age-related macular degeneration, one of the leading causes of blindness worldwide. However, the best way to store RPE to enable worldwide distribution is unknown. We investigated the effects of supplementing our previously published storage method with seven additives, attempting to improve the...

BACKGROUND AND PURPOSE Cannabidiol has been reported to be a neuroprotectant, but the neuroprotective mechanism of cannabidiol remains unclear. We studied the neuroprotective mechanism of cannabidiol in 4-hour middle cerebral artery (MCA) occlusion mice. METHODS Male MCA occluded mice were treated with cannabidiol, abnormal cannabidiol, anandamide, methanandamide, cannabidiol plus capsazepine...