Effects of feeding conditions on sensitivity to tubocurarine of nerve-muscle preparations from the mouse.
1. The effects of feeding conditions on the sensitivity to the effect of tubocurarine (dTc) in vitro were compared among various nerve-muscle preparations from mice. The mice were fed under conditions that restricted or compelled their movement for 64 days and controls were fed conventionally. 2. The sensitivity to the effect of dTc differed considerably among preparations. It was much higher in the sciatic nerve-extensor digitorum longus muscle (EDL), moderately higher in the sciatic nerve-soleus muscle (SOL) and lower in the phrenic nerve-diaphragm (DPH) in control mice. 3. The order of the sensitivity was not altered by either type of conditioning. Constant restriction of movement or compelled movement did not modify the sensitivity of DPH to the effect of dTc in vitro. 4. Compulsion facilitated the sensitivity in both SOL and EDL. Restriction selectively increased the sensitivity of EDL. Both types of conditioning selectively and significantly reduced twitch development in EDL. 5. These results indicate that the sensitivity to dTc of neuromuscular transmission reflects constant states of motor activity.
Nishimura
M
M
Department of Pharmacology, University of Obihiro School of Veterinary Medicine, Japan.
Asai
N
N
Taquahashi
Y
Y
Satoh
E
E
Shimizu
Y
Y
D000818:Animals; D003964:Diaphragm / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D004435:Eating / Q000502:physiology*; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D010805:Physical Conditioning, Animal / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology; D012584:Sciatic Nerve / Q000187:drug effects / Q000502:physiology*; D014403:Tubocurarine / Q000494:pharmacology*
D003473:Neuromuscular Nondepolarizing Agents; D014403:Tubocurarine