Changes in nicotinic acetylcholine receptor subunit mRNAs and nicotinic binding in spontaneously hypertensive stroke prone rats

We have studied nicotinic acetylcholine receptors in spontaneously hyperten sive 'stroke prone' (SHsp) rats. We found a significant decrease in I-125-a lpha-bungarotoxin binding and alpha 7 subunit mRNA levels in cortical areas of the SHsp rats with respect to Wistar Kyoto (WKy) normotensive rats. Ant ihypertensive drug treatment counteracted these changes in cerebral cortex but not in hippocampus. No significant change was instead found in [H-3]-ep ibatidine binding and alpha 4 and beta 2 subunit mRNA levels. SHsp rats sho wed decreased latency at the active avoidance test and transiently increase d threshold at both hot-plate and tail-flick tests in comparison with WKy r ats. None of these behavioral parameters was correlated with I-125-alpha-bu ngarotoxin binding in cortical areas. In conclusion, present data show a pr eferential impairment of alpha-bungarotoxin sensitive nAChRs in SHsp rats. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.