MODEL OF EMOTIONAL-STRESS IN RATS

A new experimental rat model for suppression of release of arginine va sopressin (AVP) was evaluated. Release of AVP is potentiated by physio logic stimuli, but is suppressed by emotional stress. Rats were expose d to the aggressive behavior of other rats injected with B-hydroxydopa mine hydrochloride (6-OHDA) in both lateral ventricles and subjected t o a pain stimulus applied to the tail. To ascertain whether emotional stress is induced by use of this method, plasma corticosterone, glucos e, and AVP concentrations were measured in the stressed group of rats (n = 8) placed near a group of aggressive (fighting) rats. Characteris tic changes in behavior, significant increases in plasma corticosteron e and glucose values, and lack of increase in plasma AVP concentration in stressed rats confirmed that they experienced emotional stress. Th is new model meets the experimental requirements for suppression of AV P release in rats.