The Action of Carbamic Esters and Tetraethylpyrophosphate on Normal and Curarized Frog Rectus Muscle

Hobbiger, F.

doi:10.1111/j.1476-5381.1950.tb00575.x

Cited by 19 publications

(14 citation statements)

References 14 publications

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“…Equation (I0) also describes a family of straight lines. In the absence of inhibitor it reduces to (8). If the combination is unaffected by the presence of substrate the slope…”

Section: C~ (S) C~mentioning

confidence: 99%

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Action of Inhibitors at the Myoneural Junction

Kirschner

Stone

1951

Journal of General Physiology

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On the basis of experiments performed more than 40 years ago, Langley (1) proposed a mechanism for the stimulating action of nicotine on muscle and for the antagonism of curare. He postulated that "receptive substances" are present in the neural region of the muscle, that the combination of these "radicles" with nicotine provides an adequate stimulus for contraction, and that curare competes with nicotine for the receptive substances. This concept was further developed quantitatively by A. J. Clark and his coworkers (2, 3), who used acetylcholine (Ach) as a stimulating agent and studied the inhibiting actions of atropine and of curare. Unfortunately this work seems to have been overlooked by electrophysiologists concerned with the mode of action of the "curares."It is possible to apply to this problem one of the simplest of the mathematical formulations in common use in the field of enzyme chemistry. The theory assumes that the first step in an enzyme-medlated reaction is the formation of a complex between enzyme and substrate. On this basis a relationship between reaction velocity and substrate concentration was derived by Michaelis and Menten (4). Several other authors have extended the theory (5, 6). However, the type of equation used is applicable in certain situations which are believed to involve the formation of a complex between a small molecule and a large one, usually protein, but which may involve no reaction beyond this stage. For example, the oxygenation of myoglobin is such a function of the partial pressure of oxygen (7).The following experiments offer quantitative support for the hypothesis that Ach stimulates striated muscle by some process involving the formation at the myoneural junction of an intermediary complex of the enzyme-substrate type. MethodsThe rectus abdominis muscle of the frog was dissected out and suspended for measurement of isotonic contraction. The muscle was washed in frog Ringer's solution buffered with sodium phosphate (10 -3 ~) and sodium bicarbonate (8.6 × 10 -3 ~r) and

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“…Equation (I0) also describes a family of straight lines. In the absence of inhibitor it reduces to (8). If the combination is unaffected by the presence of substrate the slope…”

Section: C~ (S) C~mentioning

confidence: 99%

“…At zero inhibitor (9) reduces to (8). As the inhibitor concentration is increased the slope of the line obtained increases, but all the lines must extrapo-1 late to the same intercept, ~.…”

Section: C~ (S) C~mentioning

confidence: 99%

Action of Inhibitors at the Myoneural Junction

Kirschner

Stone

1951

Journal of General Physiology

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“…7B), ADA usually disappears. This disappearance of ADA may be due to the depolarizing action of the excess amount of ACh (Barstad, 1962) or to the curarizing effect of neostigmine (Hobbiger, 1950).…”

Section: Antidromic Activitymentioning

confidence: 99%

Antidromic activity in the rat phrenic nerve—diaphragm preparation

Randić¹,

Straughan²

1964

The Journal of Physiology

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“…In man, P-2-AM and DAM have been found to protect against blockade of neuromuscular transmission by not only organophosphorus anti-ChE agents but also neostigmine (GROB and JoHNS 1958). In the mouse, TMB-4 protects against DFP, TEPP, diethyl-phosphostigmine, and neostigmine, but not against his-neostigmine or bis-pyridostigmine (HoBBIGER andSADLER 1588, HoBBIGER andSADLER 1959).…”

Section: Internallymentioning

confidence: 98%

Pharmacological Antagonists of the Anticholinesterase Agents

Wills¹

1963

Cholinesterases and Anticholinesterase Agents

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The Action of Carbamic Esters and Tetraethylpyrophosphate on Normal and Curarized Frog Rectus Muscle

Cited by 19 publications

References 14 publications

Action of Inhibitors at the Myoneural Junction

Action of Inhibitors at the Myoneural Junction

Antidromic activity in the rat phrenic nerve—diaphragm preparation

Pharmacological Antagonists of the Anticholinesterase Agents

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