The effect of temperature on phospholipase A2 neurotoxins ß-bungarotoxin and taipoxin effects at the neuromuscular junction Behrooz Fathi*, Alan L. Harvey** and Edward G. Rowan** *Department of Pharmacology, School of Veterinary Medicine, Ferdowsi University of Mashhad, Iran ** Strathclyde Institute of Pharmacy and Biomedical Sciences , University of Strathclyde, 27 Taylor street, Glasgow G64 ONR Pharmacological studies have been shown that the snake venom neurotoxins with distinect phospholipase A2 (PLA2) activity like B-bungarotoxin and taipoxin have an effect with three distinct phaseson rlease of acetylcholine at the neuromuscular junction. In first phase an intial transient reduction in the amount of acetylcholine release in response to an action potential, and is followed by the second phase or facilitatory phase, which is a period of time when acetylcholine release is facilitated and increased. These two early phases have been observed in experiments with p-bromophenacyl bromide (P-BPB) and in the presence of Sr2+, which inhibited enzyme activity of the PLA2. Finally, the third phase is a progressive decline, leading to complete block of transmitter release. This phase is dependent on the PLA2 enzyme activity of toxins. This study was designed to determine whether the initial phases on twitch tension caused by these two neurotoxins are modified temperature....

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