NK-1 tachykinin receptor in rat and guinea pig brains: pharmacological and autoradiographical evidence for a species difference.
The affinities of a large variety of peptide or nonpeptide tachykinin analogues were determined on membranes from rat and guinea pig brains using the selective NK-1 radioligand 3H-[Pro9]SP. Nonpeptide antagonists clearly revealed a species difference; (+/-)CP-96,345 was more potent in the guinea pig, while RP 67580 was found to be a better competitor of 3H-[Pro9]SP binding to rat brain membranes. This was confirmed on brain slices by autoradiography. Numerous brain structures were analyzed by optical densitometry. From these data, a heterogeneity of NK-1 binding sites among different structures can be excluded in both rat and guinea pig brains.
Collège de France, INSERM U 114, Chaire de Neuropharmacologie, Paris.
F
F
Petitet
J C
JC
Beaujouan
M
M
Saffroy
Y
Y
Torrens
V
V
Fardin
J
J
Glowinski
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive / Q000502:physiology; D001923:Brain Chemistry / Q000187:drug effects; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D013045:Species Specificity; D015320:Tachykinins / Q000378:metabolism*
D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter; D015320:Tachykinins