A comparative study on the contraction induced by high K/Na deficient solution in the trachea, gall bladder and urinary bladder in guinea-pig.

In the present paper, a comparative study of high K solution was carried out on the mechanical response, wet and dry weights of tissue, and extracellular space of 14C-sorbitol in the trachea, gall bladder, and urinary bladder of guinea-pig. Hyperosmotic addition of KCl to the physiological solution produced a sustained contraction, while isosmotic substitution of K for Na in the physiological solution induced a contraction followed by a small sustained one in the trachea, gall bladder or urinary bladder. At 120 min after application of the substituted KCl, Na deficient solution, it increased cell water content in the smooth muscle cells of the trachea or gall bladder, but did not change that in the urinary bladder. Both the inhibition of contraction and the swelling in the trachea or gall bladder were prevented by the hyperosmotic application of sucrose or NaCl. The substitution for NaCl with the K salts with more permeable anions (I- greater than NO3- greater than Cl-) produced a greater inhibition of contraction in the trachea and gall bladder. Although the impermeable anion C2H5CO2- did not inhibit the contraction in the trachea, this anion partially inhibited it in the gall bladder. On the other hand, the inhibition of contraction in the urinary bladder was prevented by addition of pyruvate, oxalacetate or NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)