In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 100, No. 3 ( 2003-02-04), p. 922-927
Abstract:
Scorpion venom is a complex mixture of salts, small molecules, peptides, and proteins. Scorpions employ this valuable tool in several sophisticated ways for subduing prey, deterring predators, and possibly during mating. Here, a subtle but clever strategy of venom utilization by scorpions is reported. Scorpions secrete a small quantity of transparent venom when initially stimulated that we propose to name prevenom. If secretion continues, a cloudy and dense venom that is white in color is subsequently released. The prevenom contains a combination of high K + salt and several peptides including some that block rectifying K + channels and elicit significant pain and toxicity because of a massive local depolarization. The presence of high extracellular K + in the prevenom can depolarize cells and also decrease the local electrochemical gradient making it more difficult to reestablish the resting potential. When this positive change to the K + equilibrium potential is combined with the blockage of rectifying K + channels, this further delays the recovery of the resting potential, causing a prolonged effect. We propose that the prevenom of scorpions is used as a highly efficacious predator deterrent and for immobilizing small prey while conserving metabolically expensive venom until a certain level of stimuli is reached, after which the venom is secreted.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.242735499
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2003
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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