Efect of DIDS, a disulfonic stilbene derivative, on Chloride movements in toad skeletal muscles

C.F KUSNIER, B. KOTSIAS

LIFE SCIENCES

Elsevier

Lugar: Amsterdam; Año: 1999 vol. 65 p. 271 - 277

0024-3205

Effects of DIDS, a disulfonic stilbene derivative, on chloride movements in toad skeletal muscles. Kusnier CF, Kotsias BA. Instituto de Investigaciones Médicas Alfredo Lanari-UBA, Buenos Aires, Argentina. In order to investigate the characteristics of the movement of Cl- ions in toad skeletal muscles we decided to study the relative membrane permeabilities of chloride and nitrate and the effects of DIDS (4,4'-diisothyocyanatostilbene-2,2'-disulphonate) upon the hyperpolarizations produced in muscle fibers when chloride or nitrate ions rapidly replace impermeant sulphate ions in the external solution. For experiments where membrane potential changes were recorded in response to sudden changes in extracellular solutions, small bundles from the semitendinosus muscles were used. We showed that DIDS reduced in a reversible manner the Cl- permeability (pCl) in toad skeletal muscle fibers. The results supporting this conclusion were the following. First, a diminished hyperpolarization in response to a sudden exposure of the fibers to a solution containing Cl-. In these experiments DIDS reduced the pCl/pK ratio to 5.5 from a control value of 12. Second, a smaller transient of the resting potential when [Cl]o was changed from 120 to 30 mM and vice versa. PMID: 10447212 [PubMed - indexed for MEDLINE]