The effect of arginine vasopressin on the autologous mixed lymphocyte reaction.

Arginine vasopressin (AVP) is a nonapeptide that has been shown to be released from the supraoptic and paraventricular nuclei of the hypothalamus during stress. Although noted primarily for its hemodynamic as well as homeostatic properties, AVP also appears to have an effect on the immune system. It may modulate cellular immunity via its enhancement of the autologous mixed lymphocyte response (AMLR), an effect which we have demonstrated to occur over a wide dose range with a maximum at 10(-7) M. The increase in proliferation following a single addition of AVP in a 6-day culture appears to be augmented when the peptide is added daily throughout the same culture period. Enhanced proliferation appears to be a specific response that is influenced by arginine residues in position 8 of this nonapeptide. Having provided evidence for the existence of receptors with moderate affinity for AVP, we suggest a potential modulatory role for AVP in support of the concept of a communication between the neuroendocrine and immune systems. Since various autoimmune conditions may be aggravated by stress, stress-induced release of neuropeptides such as AVP may play an important role in modulating immune regulation of these disease states.