The effects of gadolinium, a stretch-sensitive channel blocker, on diaphragm muscle. C. Coirault, M-P. Sauviat, D. Chemla, J-C. Pourny, Y. Lecarpentier #ERS Journals Ltd 1999. ABSTRACT: Stretch-activated channels (SAC) have been identified in many cell types including striated muscles. In diaphragm muscle, the influence of SAC on the length-active tension relationship remains unknown.Patch clamp experiments were performed on single fibres (n=10). In isolated diaphragm muscle from adult hamsters, the effects of gadolinium (Gd 3+ ), the most potent inhibitor of SAC blocker, on tension response to stretch at baseline were studied (n=10), after pretreatment of the muscle with 1 nmol isoproterenol (n=10), 0.5 mmol forskolin (n=6), or 0.1 mmol dibutyryl cyclic adenosine monophosphate (cAMP) (n=10). Results were compared to those obtained in low [Na + ] e (n=10), Ca 2+ -free medium (n=6) or after 5 mmol nifedipine (n=8). Gd 3+ reduced active tension measured over a range of initial muscle lengths in a concentration-dependent manner (10 and 50 mmol). In isolated fibres, mechanical stretch generated a membrane current that was sensitive to Gd 3+ . In muscles, lowering [Na + ] e mimicked the effects of Gd 3+ , while no change in the length-tension relationship was observed in Ca 2+ -free medium or after nifedipine. Drugs which increase cAMP prevented the effects of Gd 3+ on active tension. In the diaphragm, gadolinium-sensitive channels are activated during physiological changes in length and influence tension development. Moreover, cyclic adenosine monophosphate content modulates the effects of gadolinium on stretch-activated channels.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.