| pubmed-article:6341265 | pubmed:abstractText | The induction of antibody formation mediated significant changes in circulating corticosterone (CS) levels in mice. On the day of the peak plaque-forming cell (PFC) response to sheep red blood cells (SRBC) or to the trinitrophenyl (TNP) hapten, the 0800 h serum CS concentration was increased. This hormonal elevation was not observed in SRBC-immunized low responder animals which did not give a significant PFC response, thus suggesting a direct correlation between immune responsiveness and hormonal changes. A change in the circadian rhythm of CS was evident in immune animals injected with SRBC. Control animals injected with saline showed a regular circadian pattern of low CS level at 0800 h followed by a high level at 1600 h. In contrast, responding animals injected with SRBC were found to have a reversed CS pattern, i.e. the hormonal concentration was high at 0800 h and low at 1600 h, on the day of the peak PFC response. This reversal of the circadian CS pattern may have important immunoregulatory significance. The immunization-induced CS response could be significantly blocked by the administration of diazepam (DZM), an effect which implies the involvement of central hypothalamic-pituitary control of the response. | lld:pubmed |
