Gadolinium is a powerful blocker of the activation of nematocytes of Pelagia noctiluca.
The activation properties of in situ nematocytes of Pelagia noctiluca (Scyphozoa) were investigated by physical contact with a gelatin probe that, besides stimulating the nematocyte battery, retains the discharged nematocysts, thereby allowing a quantitative evaluation of the response. In oral arms previously treated with 2 mmol l-1 La3+ the discharge was inhibited. This result confirms the Ca(2+)-dependence of nematocyte activation. A similar inhibitory effect was induced by treatment with 20 mumol l-1 Gd3+, a powerful blocker of mechanosensitive ion channels. It is therefore proposed that Ca(2+)-permeable mechanosensitive channels are involved in the activation of nematocytes. 50 mumol l-1 Gd3+ added to the gelatin probe was effective in otherwise untreated oral arms. This result suggests that Gd3+ could be useful in preventing stings from harmful Cnidaria.
Salleo
A
A
Institute of General Physiology, University of Messina, Italy.
La Spada
G
G
Barbera
R
R
D000818:Animals; D002118:Calcium / Q000502:physiology; D005682:Gadolinium / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects; D008465:Mechanoreceptors / Q000187:drug effects / Q000502:physiology; D037401:Scyphozoa / Q000187:drug effects* / Q000502:physiology
D007473:Ion Channels; D005682:Gadolinium; D002118:Calcium