The effect of antiadrenaline compounds on acetylcholine responses of frog rectus abdominis muscle

Article date: February 1970

By: N. D. EDGE in Volume 38, Issue 2, pages 386-393

. Nine antiadrenaline compounds and ergometrine have been examined for their effect on acetylcholine (ACh)‐induced contractures of the frog isolated rectus abdominis muscle.

. Tolazoline caused potentiation (pP2 = 4·14 at 7 min). Slightly higher concentrations of tolazoline caused antagonism (pA2 = 3·68 at 37 min).

. No potentiation of ACh responses was seen with any of the remaining compounds, which all antagonized ACh responses. Phenoxybenzamine gave the highest, and ergometrine the lowest, pA2 values.

. In the concentrations needed to determine pA2, yohimbine and ergometrine also had other effects on the muscle.

. These results are discussed in the context of previous findings.

. Nine antiadrenaline compounds and ergometrine have been examined for their effect on acetylcholine (ACh)‐induced contractures of the frog isolated rectus abdominis muscle.

. Tolazoline caused potentiation (pP2 = 4·14 at 7 min). Slightly higher concentrations of tolazoline caused antagonism (pA2 = 3·68 at 37 min).

. No potentiation of ACh responses was seen with any of the remaining compounds, which all antagonized ACh responses. Phenoxybenzamine gave the highest, and ergometrine the lowest, pA2 values.

. In the concentrations needed to determine pA2, yohimbine and ergometrine also had other effects on the muscle.

. These results are discussed in the context of previous findings.

DOI: 10.1111/j.1476-5381.1970.tb08526.x

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