title: Effects of honey containing grayanotoxin I on frog gastrocnemius muscle.
abstract: The presence of grayanotoxins (GTX-I, GTX-II and GTX-III) in honey samples from the Mediterranean Sea and Black Sea regions of Turkey and the effect of honey containing GTX-I on the threshold stimulus voltage of frog gastrocnemius muscle were studied. We used 2 groups of gastrocnemius muscles isolated from curarized or noncurarized frogs. The threshold voltage was measured by external perfusion with a polygraphic system. Isolated muscle preparations were perfused separately with Clark-frog-Ringer's solution containing honey solutions from the Mediterranean Sea region (normal) or with honey solutions from the Black Sea region (GTX-I-containing, poisonous). There was no significant difference between the normal and poisonous honey groups data with the curarized preparations. But in the noncurarized preparations, the honey containing GTX-I significantly decreased the threshold voltage in comparison with normal honey. These findings suggest the effect of GTX-I on frog neuromuscular junctions is due to an increase in membrane permeability to sodium ions.
authors.affiliation: Department of Physiology, Faculty of Medicine, Erciyes University, Kayseri, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Ozesmi
authors.forename: S
authors.initials: S
authors.lastname: Aydogan
authors.forename: M
authors.initials: M
authors.lastname: Ascioglu
mesh_terms: D000818:Animals; D004224:Diterpenes / Q000633:toxicity*; D005506:Food Contamination; D006614:Hindlimb; D006722:Honey / Q000633:toxicity*; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009132:Muscles / Q000294:innervation*; D009469:Neuromuscular Junction / Q000187:drug effects*; D011895:Rana ridibunda
chemical_list: D004224:Diterpenes; C001311:grayanotoxin I