Induction of c-Fos and zif268 in the nociceptive amygdala parallel abstinence hyperalgesia in rats briefly exposed to morphine.

Opioid-induced analgesia can be followed by spontaneous pain in humans, and hyperalgesia in rodents. In this study, opioid-induced hyperalgesia was measured by the tail-flick test when acute abstinence was precipitated by administering naloxone to drug naive rats that had experienced morphine analgesia for only 30 min. In a further experiment, the drug treatment that previously caused opioid-induced hyperalgesia was found to increase neurons expressing nuclear c-Fos or zif268 proteins in extended amygdalar regions targeted by projections of the ascending spino-parabrachio-amygdaloid nociceptive pathway.

The effect of diclofenac on the expression of spinal cord c-fos-like immunoreactivity after ischemia-reperfusion-induced acute hyperalgesia in the rat tail.

Ischemia-reperfusion of the rat tail for 20 min induces local acute hyperalgesia of approximately 1-h duration. We studied how this stimulus affected the expression of c-fos-like immunoreactivity (c-fos-LI) labeling of neurons of the sacral spinal cord, and how diclofenac pretreatment influenced the outcome. After ischemia, the number of c-fos-LI-labeled neurons was significantly increased when assessed at 60, 90, and 120 min after reperfusion (to 183%, 283%, and 164% of control, respectively; all P < 0.

Pathogenesis of abdominal aortic aneurysms: possible role of differential production of proteoglycans by smooth muscle cells.

Purpose: In vivo and in vitro observations strongly suggest that marked differences exist in the phenotype, growth, and matrix-producing capabilities of distinct smooth muscle cell subpopulations. An earlier study from our laboratory showed differences in matrix metalloproteinase expression patterns in cultures of medial smooth muscle cells from tissue affected by abdominal aortic aneurysm (AAA) or atherosclerotic occlusive disease and from normal arterial tissue. In this study we were interested in ascertaining whether smooth muscle cells from the same sample groups also synthesized different proteoglycan profiles that correlated with vascular disease.

Detection of aggregatable proteoglycan populations by affinity blotting using biotinylated hyaluronan.

Proteoglycans (PGs) were extracted from a range of cartilaginous ovine connective tissues using 4 M GuHCl and separated by composite agarose polyacrylamide gel electrophoresis. Individual PG populations resolved by this electrophoretic system were identified in toluidine blue and Stains-All stained gel segments and also by conventional immunoblotting using a range of monoclonal antibodies to defined PG epitopes. These PG species were compared with aggregatable PG populations identified by affinity blotting using a biotinylated hyaluronan, and an avidin alkaline phosphatase/nitro blue tetrazolium 5-bromo-4-chloro indolyl phosphate detection system.