Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

( sup 3 H)saxitoxin as a marker for canine deep muscular plexus neurons

Journal Article · · American Journal of Physiology; (USA)
OSTI ID:6254173
; ; ; ;  [1]
  1. McMaster Univ. Medical Center, Hamilton, Ontario (Canada)
The objectives of this study are (1) to examine the potential of ({sup 3}H)saxitoxin binding as a marker for the neuronal membranes in canine small intestinal muscle membrane preparations, (2) to develop a synaptosomal preparation from deep muscular plexus, and (3) to partially characterize ({sup 3}H)saxitoxin binding to this fraction. A purified synaptosomal fraction, relatively low in the smooth muscle plasma membrane marker enzyme 5{prime}-nucleotidase but enriched in ({sup 3}H)saxitoxin binding was obtained on sucrose density gradient. Vasoactive intestinal peptide immunoreactivity was also highest in this fraction. The binding was rapid at 20{degree}C with quick and complete dissociation after the addition of excess unlabeled tetrodotoxin (TTX). Scatchard analysis of the saturation binding data revealed a single population of binding sites. The affinity constants calculated from the kinetic and saturation data were in close agreement. TTX competed for the binding, whereas veratridine and guanidinium hydrochloride did not. Monovalent and divalent cations had differential effects on the binding.
OSTI ID:
6254173
Journal Information:
American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 255:4; ISSN 0002-9513; ISSN AJPHA
Country of Publication:
United States
Language:
English