Frog cutaneous pectoris muscles were treated with low doses of crude black widow spider venom (BWSV) or purified alpha-latrotoxin, and neuromuscular transmission, quantal secretion, changes in ultrastructure and uptake of horseradish peroxidase (HRP) were studied. When these agents were applied to muscles bathed in a Ca2+-free solution with 1 mM EGTA and 4 mM Mg2+, the rate of quantal secretion...

To test if recovery of neuromuscular transmission is complete after the use of neostigmine under standardized conditions, we have measured adductor pollicis mechanical activity in response to 0.1 Hz (twitch height), train-of-four (TOF) and 100 Hz (RF 100 Hz) ulnar nerve stimulations. We studied 56 adult anaesthetized (thiopentone, fentanyl, nitrous oxide in oxygen) patients, allocated randomly ...

Enteric inhibitory motoneurons use nitric oxide and a purine neurotransmitter to relax gastrointestinal smooth muscle. Enteric P/Q-type Ca2+ channels contribute to excitatory neuromuscular transmission; their contribution to inhibitory transmission is less clear. We used the colon from tottering mice (tg/tg, loss of function mutation in the α1A pore-forming subunit of P/Q-type Ca2+ channels) to...

Myasthenia gravis is a disorder of impaired neuromuscular transmission resulting in weakness and abnormal fatigability on exertion, improved by anti-acetyl cholinesterase drugs. A number of drugs are known to exacerbate myasthenia gravis or interfere with neuromuscular transmission. We report a case of D-penicillamine induced myasthenia gravis who developed ptosis, diplopia and easy fatigabilit...

Drug-induced myasthenic syndromes are caused by numerous medications of various classes. D-penicillamine and interferon alpha lead to an autoimmune process similar to spontaneous myasthenia gravis, whereas many other agents produce weakness by a direct compromise of neuromuscular transmission. A particular problem in clinical practice is the deterioration of neuromuscular transmission by anesth...