Recent development in hormone research.

Abstract

A classical distinction between endocrine cells and neurons cannot be accepted without exception. This dichotomy was first challenged by the concept of neurosecretion. Recent observations indicate that hormone synthesis takes place in many extraendocrine tissues since the gene expression for prohormone synthesis seems to be common for all eukaryotes although the secretion of biological active hormone products is limited by posttranslational processing for differentiated cells. Increasing number of data support the view that regulation of pituitary hormone secretion is under multifactorial control in addition to specific signaling molecular effects of hormone-releasing hormones. Such modulators are co-secreted messengers from hypothalamic sources or co-functioning at the pituitary cell level. Multichannel regulation of pituitary tropic hormones appears to be important for understanding the interactions of pharmacological agents with pituitary hormone release, on the one hand, and the modulation of hormone release in pathological conditions, on the other hand. Perinatal transient hazards may induce permanent alterations in adaptive behavior when tested in adult age. Corticosteroid-induced deviation of avoidance behavioral reactions may be opposed by simultaneous administration of ACTH-like peptides. These observations revealed that a balance of the glucocorticoids and ACTH-like peptides in perinatal period basically determine the adaptative reaction of animals in adult age. Immune system may be called as a mobile brain since its tremendous information capacity and its responsiveness to alterations of chemical environmental signals. Recent data support the view that there is a bidirectional communication between the neuro-endocrine adaptational axis and the immune system. Stress hormones can alter the immune response and mononuclear cells produce factors that change the neuroendocrine regulation. In addition to these, prohormones are synthesized in mononuclear cells that may be involved in regulation of signalization between cells and in activation of endocrine system and brain functions.