Voltage-sensitive Na+ channels in the neurohypophysis of the rat as demonstrated by 125I-labelled scorpion toxin.
Fresh rat neural lobe slices were incubated in the presence of [125I] alpha-scorpion toxin (ScTX), a specific marker of Na+ channels. Quantitative electron microscope autoradiography revealed preferential, irregularly spaced labeling of the axolemma of neurosecretory axons, with a significantly higher crude specific activity than any other neuronal or non-neuronal compartment. The number of specific binding sites at the neural lobe surface was calculated to be about 23 per microns2 of axolemma.
D000818:Animals; D001345:Autoradiography; D001369:Axons / Q000502:physiology; D007425:Intracellular Membranes / Q000502:physiology; D007457:Iodine Radioisotopes; D007473:Ion Channels / Q000502:physiology*; D008297:Male; D008854:Microscopy, Electron; D010904:Pituitary Gland, Posterior / Q000502:physiology*; D051381:Rats / Q000502:physiology*; D011919:Rats, Inbred Strains; D012604:Scorpion Venoms / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*
D007457:Iodine Radioisotopes; D007473:Ion Channels; D012604:Scorpion Venoms; D012964:Sodium