Specific changes in the conformation of blood albumin molecule during stress exposures and administration of cytokines or oligopeptides

Abstract

Structural peculiarities of the albumin molecule in blood samples from behaviorally passive and active rats
(prognostically predisposed and resistant to stress exposures, respectively) were evaluated after administration of cytokines and oligopeptides. We revealed that acute stress is followed by a change in the properties of albumin sites. Under these conditions fluorescence of the CAPIDAN probe (criterion for the state of albumin binding sites) is elevated in active specimens, but decreases in passive animals. Pretreatment with Semax and delta sleep-inducing peptide, which modulate the sensitivity to negative consequences of stress, was shown to affect albumin parameters in the blood. For example, Semax abolishes a conformational change of the serum albumin molecule in rats predisposed to post-stress abnormalities in physiological functions. Our study showed that a proinflammatory cytokine interleukin-1β and anti-inflammatory cytokine interleukin-4 have a unidirectional effect on the properties of albumin binding sites in specimens with various behavioral characteristics. Interleukin-1β and interleukin-4 prevent a change in the binding capacity of albumin in stress-resistant and stress-predisposed animals after a negative emotiogenic exposure. The influence of cytokines on blood albumin parameters is more pronounced in behaviorally active rats than in passive specimens, which results from differences in the total albumin concentration in these animals under basal conditions. Moreover, these features can be related to the specifics of metabolic processes in animals with various behavioral characteristics.