Date of Award
College of Science, Engineering, and Technology (COSET)
MS in Biology
Dr. Yvonne Hogan
Synaptic plasticity in the form of long-term potentiation (LTP) exists in sympathetic ganglia. This project examines the possibility that in sympathetic ganglia which regulate and control blood pressure, LTP may be involved in the expression of some forms of hypertension. Long lasting enhancement of the basal tone of ganglionic transmission ( as with LTP) results in sustained constriction of blood vessels which leads to elevated blood pressure. Results from this laboratory presented compelling evidence that LTP in the superior cervical ganglion is dependent on activation of serotonin 5-HT3 receptors. Long lasting (hours) LTP in sympathetic ganglia is induced by subjecting the ganglion to a brief (20 sec) train of impulses (20 Hz). Subsequent trains of stimuli, no matter how often or how long they are applied, do not significantly influence the already enhanced transmission. Our preliminary results indicate that ganglia from genetically hypertensive rats, the SHR, express no LTP or one that is significantly lower in magnitude than the LTP expressed by ganglia from the normotensive WKY rats. Since we have proven that LTP in ganglia requires activation of 5-HT3, the aim of this project is to determine whether treatment of SHR with a serotonin 5-HT3 receptor blocker would lower their blood pressure. In this study we will use the genetic model, SHR and their normotensive counterpart the WKY rats and the stress (Intruder) model to prove that chronic treatment with a 5-HT3 receptor antagonist, will decrease blood pressure in hypertensive but not normotensive animals. A positive result would establish LTP as a possible mechanism underlying this form of hypertension.
Sockwell, Deanna L., "Tropisetron Inhibits NeuroGenic (Stress-Induced) Hypertension but not Genetic Hypertension" (1999). Theses (Pre-2016). 99.