Figure 2.

Desensitization of the σ₁ response via cPKC. (A) Desensitization of the σ₁ effect on the integrated XII activity after 30 min of perfusion (open bar). (B) Desensitization induced by successive, short perfusions of PTZ (Upper) was prevented by a preperfusion of GF-109,203x (50 nM, 5 min; Lower). (C) Mean values of the effects of successive, short perfusions of σ₁ in control conditions and after GF-109,203x and Gö-6976 perfusions, which prevented the PTZ-induced desensitization. (D) Autoradiogram after a long perfusion of PTZ revealed a phosphorylated, 28-kDa protein at the level of the σ₁ receptor protein (revealed by Western blot analysis), which did not appear after GF-109,203x perfusion. In the Western blot, this band disappeared in the presence of the synthetic peptide anti-PBP45 (pbp-45) (3).