title: Octopamine reduces potassium permeability of the glia that form the insect blood-brain barrier.
abstract: Octopamine caused only a slight reduction in the potential across the perineurial glia of the cockroach, had no effect upon sodium-induced changes in potential, but did reduce potassium-induced changes (at 10(-7) M and above). The effect of 10(-7) M octopamine was accompanied by a rise in resistance, was mimicked by 10(-7) M synephrine and blocked by 10(-6) M phentolamine. Transperineurial potassium permeability was reduced by 10(-6) M octopamine. It is concluded that octopamine receptors mediate a reduction in potassium conductance of the basolateral membrane of these glia, and a reduction in the net potassium permeability of the barrier.
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects*; D005724:Ganglia / Q000187:drug effects*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009457:Neuroglia / Q000187:drug effects*; D009655:Octopamine / Q000494:pharmacology*; D010526:Periplaneta; D010646:Phentolamine / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D013578:Synephrine / Q000494:pharmacology
chemical_list: D009655:Octopamine; D013578:Synephrine; D011188:Potassium; D010646:Phentolamine