Behavioral studies on the putative gamma-type endorphin receptor using different antibodies.
To investigate the significance of endogenous, neuroleptic-like gamma-type endorphins and their putative receptors, polyclonal and monoclonal antibodies against gamma-type endorphins, which may bio-inactivate the ligands for the receptors, and monoclonal anti-idiotype antibodies, which presumably bind to the receptors, were injected into the nucleus accumbens of the rat brain. The desenkephalin-gamma-endorphin-induced antagonism of the hypomotility response elicited by challenge with apomorphine injected into the nucleus accumbens was used as test system. Both the anti-desenkephalin-gamma-endorphin antibodies and anti-idiotype antibodies blocked the action of exogenous desenkephalin-gamma-endorphin. Thus, the anti-idiotype antibodies may serve as receptor antagonists. Chronic treatment (injection into the nucleus accumbens) with the anti-idiotype antibodies induced sustained hypermotility, decreased habituation and impaired passive avoidance behavior. In such treated animals local treatment with apomorphine did not elicit hypomotility. It is suggested that gamma-type endorphins influence the setpoint for feedback regulation in dopaminergic neurons equipped with gamma-type endorphin receptor systems.
Van Ree
J M
JM
Department of Pharmacology, Rudolf Magnus Institute for Neurosciences, Utrecht University, Netherlands.
Wolterink
G
G
Igarashi
Y
Y
Vanderschuren
L
L
Wiegant
V M
VM
Rust
C J
CJ
Bruning
H W
HW
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D001058:Apomorphine / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects*; D018491:Dopamine Agonists / Q000494:pharmacology; D005246:Feedback / Q000502:physiology; D006185:Habituation, Psychophysiologic / Q000187:drug effects; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D010121:Oxytocin / Q000276:immunology; D051381:Rats; D017208:Rats, Wistar; D011954:Receptors, Dopamine / Q000187:drug effects; D011957:Receptors, Opioid / Q000187:drug effects* / Q000276:immunology; D018823:gamma-Endorphin / Q000276:immunology*
D000911:Antibodies, Monoclonal; D018491:Dopamine Agonists; D011954:Receptors, Dopamine; D011957:Receptors, Opioid; D010121:Oxytocin; D018823:gamma-Endorphin; D001058:Apomorphine