title: Differential presynaptic effects of hexachlorocyclohexane isomers on noradrenaline release in cerebral cortex.
abstract: To investigate presynaptic effects of hexachlorocyclohexane (HCH) isomers, the release of noradrenaline (NA) in brain tissue was analyzed using rat cerebral cortical slices preloaded with [3H]-NA. gamma-HCH (lindane) 50 microM significantly enhanced the [3H]-NA release evoked by 15-25 mM K+. alpha- and beta-HCH (50 microM) did not produce any significant effect on K(+)-evoked [3H]-NA release. delta-HCH (50 microM) induced a significant decrease of the 25 mM K(+)-evoked release of [3H]-NA. The effect of the gamma- and delta-HCH isomers on the presynaptic action of the alpha 2-agonist clonidine and the alpha 2-antagonist yohimbine was also studied. The presynaptic inhibitory effect of clonidine and the stimulatory effect of yohimbine on [3H]-NA release was attenuated by lindane and delta-HCH, respectively. These results are consistent with a presynaptic action of the HCH isomers on noradrenergic release processes.
authors.affiliation: Department of Pharmacology and Toxicology, Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.
authors.forename: R M
authors.initials: RM
authors.lastname: Cristòfol
authors.forename: E
authors.initials: E
authors.lastname: Rodríguez-Farré
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003000:Clonidine / Q000494:pharmacology; D001556:Hexachlorocyclohexane / Q000494:pharmacology*; D066298:In Vitro Techniques; D007536:Isomerism; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013223:Statistics as Topic; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D015016:Yohimbine; D001556:Hexachlorocyclohexane; D003000:Clonidine; D011188:Potassium; D009638:Norepinephrine