Morphological changes in immune and endocrine organs of stressed mice after administration of a gonadotropin-releasing hormone analogue.

Administration of Surfagon, a gonadotropin-releasing hormone analogue, in doses of 0.1 and 5.0 microg/kg before emotional nociceptive stress increased lymphocyte migration from the thymus, decreased the volume of lymphoid tissue in the spleen and thymus, reduced the width of the zona fasciculata and increased the width of the zona glomerulosa in the adrenal cortex of male CBA mice. These effects of the peptide persisted in castrated animals. Surfagon prevented stress-induced activation of the adrenal glands and accidental transformation of the thymus and spleen in castrated animals.