|Neuropeptide Y receptors from calf brain: effect of crude Conus venom preparations on NPY binding|Czerwiec, E.; De Backer, J.-P.; Vauquelin, G.; Vanderheyden, P.M.L. (1996). Neuropeptide Y receptors from calf brain: effect of crude Conus venom preparations on NPY binding. Neurochemistry International 29(6): 669-676. dx.doi.org/10.1016/S0197-0186(96)00066-6
In: Neurochemistry International. PERGAMON-ELSEVIER SCIENCE LTD: Oxford. ISSN 0197-0186, more
|Authors|| || Top |
- Czerwiec, E.
- De Backer, J.-P.
- Vauquelin, G.
- Vanderheyden, P.M.L.
NPY receptors are identified in calf frontal cortex and hippocampus membrane preparations by binding of N-[propionyl-3H] neuropeptide Y. Saturation and competition binding data with PYY, NPY-(18–36) and NPY itself fit with a single class of sites: for the radioligand KD = 1.4 ± 0.5 nM, Bmax = 434 ± 180 fmol/mg protein in frontal cortex, KD = 0.7 ± 0.2 nM, Bmax = 267 ± 50 fmol/mg protein in hippocampus. Competition curves of the Y1-subtype selective agonist [Leu31, Pro34]NPY are biphasic in both membrane preparations: high affinity sites (i.e. Y1-subtype) amount to 80% in frontal cortex and 23% in hippocampus. The remaining sites are of the Y2-subtype. Out of 23 Conus venom preparations, 17 inhibit the binding of [3H]NPY in both membrane preparations, but only two of them (from Conus aulicus and C. pennaceus) do so with high potency (ic50 < 5 μg protein/ml). Only one venom preparation (from C. mercator) had weak discriminatory properties (ic50Y2/ic50Y1 = 6). Venom from C. anemone increased the [3H]NPY binding 5-fold and with an ic50 of 15–18 μg protein/ml. This binding occurred to the venom itself and was unrelated to the NPY receptors since it was equally potent when displaced by [Leu31, Pro34]NPY, NPY-(18–36), PYY and NPY.