AJP - Endocrinology and Metabolism, Vol 267, Issue 6 E915-E920, Copyright © 1994 by American Physiological Society
Changes in regional protein synthesis in rat brain and pituitary after systemic interleukin-1 beta administration
L. M. Williams, P. E. Ballmer, L. T. Hannah, I. Grant and P. J. Garlick
Rowett Research Institute, Bucksburn, Aberdeen, United Kingdom.
A convenient and sensitive method has been developed for measuring changes
in protein synthesis in discrete areas of the brain and pituitary of
conscious freely moving rats. A single injection of high-concentration
low-specific activity L-[35S]methionine is given to flood amino acid
precursor pools, thereby equalizing the specific activity of the
L-[35S]methionine throughout the tissue. Unincorporated L-[35S]methionine
is removed from cryostat sections by treatment with perchloric acid (2%)
before quantitative autoradiography. The sensitivity of this technique is
demonstrated by the detection of changes in protein synthesis in regions of
the brain and pituitary after systemic administration of interleukin-1
beta, a cytokine that has centrally mediated effects but which is not
thought to cross the blood-brain barrier. Areas of the brain found to
exhibit significant increases in protein synthesis were the subfornical
organ, the choroid plexus, the medial habenular, the dentate gyrus, and the
anterior and posterior lobes of the pituitary. In the brain, the cingulate
cortex and the pineal gland showed significant decreases in the rate of
protein synthesis.
