Abstract
To determine if the cardiovascular effects of chronic treatment with ketanserin would vary with increasing age, ketanserin was given by daily gavage for 14 days to male Sprague-Dawley rats at ages 4, 14, or 24 months. Before treatment, 24-month-old rats had higher blood pressures and weaker reflex heart rate responses than younger rats. Treatment with ketanserin caused hypotension, enhanced bradycardia, attenuated reflex tachycardia, and reversed serotonin (5-HT) responses, with all effects being more pronounced in 24-month-old rats than in younger rats. None of the age-related effects can be attributed to alpha-adrenergic blockade because they occurred even while cardiovascular responses to phenylephrine, an alpha 1-adrenergic agonist, were unaltered at any age. On the other hand, serotonergic blockade seems a more likely explanation because reversal or enhancement by ketanserin of cardiovascular responses to serotonin was age-related, being more marked in 14- and 24- than in 4-month-old rats. Our results suggest that as the cardiovascular effects of ketanserin become more pronounced with advancing age, 5-HT blockade intensifies and bradycardia becomes augmented until the ensuing cardiac inhibition eventually accentuates the hypotensive effects in older rats.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
