TELEMETERED RECORDING OF BLOOD-PRESSURE AND HEART-RATE IN DIFFERENT STRAINS OF RATS DURING CHRONIC SOCIAL STRESS

The role of stress in the etiology of high blood pressure and the biol ogical mechanisms involved are still not clear. We have recently devel opped a paradigm of chronic social stress based on social instability and cohabitation with females, in which the different neuroendocrine r esponses to stress can be independently triggered. In this work, we us ed a telemetry technique to record blood pressure and heart rate chron ically in freely moving undisturbed rats to study the influence of chr onic social stress on blood pressure and heart rate in normotensive ra ts (Wistar and Long-Evans) and in Bordeline Hypertensive Rats (BHR). N o increase of blood pressure could be seen for one month of social str ess in either strain. Wistar and Long-Evans rats were fully sensitive to social pressure, as shown by the changes in body weight, but may la ck a specific vulnerability of the cardiovascular system. Conversely, Borderline Hypertensive rats have the genetic predisposition to develo p hypertension but do not appear to be sensitive to social stimulation s in the present experimental conditions. The experimental protocol us ed here should allow further investigation of the various possible sou rces of failure to induce chronic cardiovascular changes by social str ess, such as blood pressure measurement techniques, social stress prot ocols, and genetic aspects of psychobiological and cardiovascular vuln erability to stress.