Effect of surgical stress on benzodiazepine receptors as a consequence of placebo pellet implantation in rat: an autoradiographic study.
This paper reports modifications in benzodiazepine (BZ) receptors induced by minimally invasive surgery, such as pellet implantation, a widely used surgical process for chronic drug administration. The intrinsic stress induced by this manipulation on BZ receptors was analysed in an autoradiographic saturation study determining the affinity (K(D)) and total number (Bmax) of binding sites of a number of brain areas from the mesencephalon, cerebral cortex, hippocampus, and cerebellum. The radioligand used for the study was [3H]flunitrazepam, which permitted overall characterization of BZ binding sites. Use of the specific BZ1 agonist zolpidem as an inhibitor of this radioligand permitted the direct characterization of subtype 2 (BZ2) and the indirect characterization of subtype 1 receptor (BZ1). Significant increases in Bmax and K(D) values were observed in pellet-implanted animals with respect to those not implanted. The results support the notion of an up-regulation of these receptors, mainly in BZ1 receptors, following sustained desensitization as a result of the surgical stress induced by pellet implantation.
Revilla
V
V
Departmento de Biología Celular, Universidad de León, Spain.
Soria
C
C
Aller
M I
MI
Calvo
P
P
Fernández-López
A
A
D000818:Animals; D001345:Autoradiography / Q000379:methods; D001921:Brain / Q000378:metabolism*; D004343:Drug Implants; D005445:Flunitrazepam / Q000493:pharmacokinetics; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D009928:Organ Specificity; D010919:Placebos; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000378:metabolism*; D013312:Stress, Physiological / Q000378:metabolism*; D014316:Tritium
D004343:Drug Implants; D010919:Placebos; D011963:Receptors, GABA-A; D014316:Tritium; D005445:Flunitrazepam