title: Triazines facilitate neurotransmitter release of synaptic terminals located in hearts of frog (Rana ridibunda) and honeybee (Apis mellifera) and in the ventral nerve cord of a beetle (Tenebrio molitor).
abstract: Three triazine herbicides, atrazine, simazine and metribuzine, and some of their major metabolites (cyanuric acid and 6-azauracil) were investigated for their action on synaptic terminals using three different isolated tissue preparations from the atria of the frog, Rana ridibunda, the heart of the honeybee, Apis mellifera macedonica, and the ventral nerve cord of the beetle, Tenebrio molitor. The results indicate that triazines facilitate the release of neurotransmitters from nerve terminals, as already reported for the mammalian central nervous system. The no observed effect concentration, the maximum concentration of the herbicide diluted in the saline that has no effect on the physiological properties of the isolated tissue, was estimated for each individual preparation. According to their relative potency, the three triazines tested can be ranked as follows: atrazine (cyanuric acid), simazine>metribuzine (6-azauracil). The action of these compounds on the cholinergic (amphibians, insects), adrenergic (amphibian) and octopaminergic (insects) synaptic terminals is discussed.
authors.affiliation: Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University, Thessaloniki 54124, Greek Macedonia, Greece.
authors.forename: Chrisovalantis
authors.initials: C
authors.lastname: Papaefthimiou
authors.forename: Georgia
authors.initials: G
authors.lastname: Zafeiridou
authors.forename: Aglaia
authors.initials: A
authors.lastname: Topoglidi
authors.forename: George
authors.initials: G
authors.lastname: Chaleplis
authors.forename: Stella
authors.initials: S
authors.lastname: Zografou
authors.forename: George
authors.initials: G
authors.lastname: Theophilidis
mesh_terms: D000818:Animals; D001516:Bees; D004305:Dose-Response Relationship, Drug; D005260:Female; D017952:Ganglia, Invertebrate / Q000187:drug effects* / Q000378:metabolism; D006321:Heart / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology; D009206:Myocardium / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000187:drug effects* / Q000378:metabolism; D011895:Rana ridibunda; D013712:Tenebrio; D014227:Triazines / Q000494:pharmacology*
chemical_list: D018377:Neurotransmitter Agents; D014227:Triazines