Cardiovascular Responses to Acute Mental ‘Stress’ in Spontaneously Hypertensive Rats

1. The hypothalamic defence reaction was assessed in spontaneously hypertensive rats (SHR) and normotensive control rats (NCR). 2. SHR exhibited an apparently true hyper-reactivity of central autonomic structures mediating emotional behaviour during mental stress present in early as well as in established hypertension. 3. This hyper-reactivity is thought, therefore, to be a genetically linked factor predisposing to hypertension in SHR, rather than a consequence of the hypertensive state.