Regulation of IL-1β mRNA and the interleukin-converting enzyme: (A) mRNA from lesioned or sham injected animals, with estrogen or control pellets was reverse transcribed and amplified using primers specific for IL-1β and cyclophilin. PCR product was fractioned on an agarose gel and photographed under UV illumination. An image of these gels is shown here, with 4 representative animals from each group. At 24 h post injury, NMDA lesions increased IL-1β mRNA, however, estrogen-treated (OVX+E) animals were no different from the control-pellet (OVX) treated animals. (B) Since the mature form of IL-1β is obtained through cleavage of IL-lβ precursor protein by caspase-1, activity for this enzyme was also assayed. Neither NMDA lesions nor estrogen treatment caused any significant changes in caspase-1 activity at 24 h post injury. Histogram bars represent means ± SEM for the entire group (n = 6). *:p < 0.05.