Interleukin-1 receptor type I mRNA levels in brain regions from male and female rats.

Interleukin-1 (IL-1) induces a variety of neurological manifestations by direct action in the central nervous system (CNS). The IL-1 receptor type I (IL-1RI) mediates IL-1 signalling. In the present study, the steady-state content of IL-1RI mRNA was determined by a sensitive RNase protection assay in brain regions obtained from normal male and nonestrous female Wistar rats. The results show that brain regions differ in IL-1RI mRNA content. Highest levels of IL-1RI mRNA were detected in the male and female cerebral cortex. High levels of IL-1RI mRNA were also observed in the brain stem and its structures, and the cerebellum. Male and female rats exhibited similar differential profile of IL-1RI mRNA levels in the frontal cortex, hippocampus, hypothalamus, and cerebellum. The present data on brain distribution of IL-1RI mRNA levels suggest that distinct brain regions may depend differentially on the IL-1 system.