Opioid receptor types for endogenous enkephalin in the thoracic ganglion of the crab, Carcinus maenas.
In crustaceans, the endogenous opioid peptides, enkephalins, are known to be concentrated in the thoracic ganglion, although they have been demonstrated in all parts of the nervous system. Bmax and Kd measurements have been obtained for the binding of ligands used to characterize delta- and kappa-type opioid receptors in vertebrates. High- and low affinity binding of [3H] [2-D-Pen5-D Pen] enkephalin ([3H]DPDPE) has been measured with a Kd = 9.2 +/- 2.4 nM, Bmax = 153 fmol/mg, and Kd = 243 +/- 27 nM, Bmax = 1.785 pmol/mg, respectively. In addition a kappa-type receptor with Kd 85.5 +/- 12.6 nM and Bmax = 21.138 pmol/mg protein has been recorded. Binding characteristics of several ligands were monitored. Electrophoretic studies of affinity chromatographically purified receptor fractions revealed a molecular mass of 60 kDa. Isoelectric focusing showed a specific binding of [3H]DPDPE to thoracic ganglion membranes at a pl of 5.5.
Abteilung Zoophysiologie, Fachbereich Biologie, C.v.O.-Universität, Oldenburg, Germany.
J
J
Hanke
A
A
Willig
P P
PP
Jaros
D000701:Analgesics, Opioid / Q000378:metabolism; D000818:Animals; D003386:Brachyura / Q000502:physiology*; D020881:Enkephalin, D-Penicillamine (2,5)-; D004745:Enkephalins / Q000378:metabolism*; D016314:Ethylketocyclazocine / Q000378:metabolism; D005724:Ganglia / Q000737:chemistry*; D011869:Radioligand Assay; D017465:Receptors, Opioid, delta / Q000302:isolation & purification*; D017473:Receptors, Opioid, kappa / Q000302:isolation & purification*
D000701:Analgesics, Opioid; D004745:Enkephalins; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D016314:Ethylketocyclazocine; D020881:Enkephalin, D-Penicillamine (2,5)-