COMPARISON OF THE EFFECTS OF CAFFEINE AND A 2‐ALKYL‐1,2,3‐BENZOTRIAZINIUM IODIDE ON FROG RECTUS ABDOMINIS

Article date: July 1977

By: C.K. MUIR, N.C. SCOTT in Volume 60, Issue 3, pages 375-378

1 The mode of action of 2‐n‐propyl‐4‐p‐tolylamino‐1,2,3‐benzotriazinium iodide (TnPBI), which induced contractures of frog rectus abdominis muscle, was investigated.

2 TnPBI caused contractures of frog rectus abdominis when the muscle had been depolarized with potassium chloride.

3 Experiments with TnPBI and caffeine in calcium‐free Ringer suggested that both compounds produce contractures by releasing intracellular bound calcium.

4 It is suggested that at least two calcium stores are involved, one of which is sensitive to caffeine while both are sensitive to TnPBI.

DOI: 10.1111/j.1476-5381.1977.tb07511.x

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