Prolonged effect of the tricyclic antidepressant, mianserin on the serotonin and histamine content of young rats’ white blood cells and mast cells. A case of late-imprinting

Abstract

Perinatal encounter of a hormone and its developing target receptor sets the receptor-hormone-signal transduction complex for life (hormonal imprinting). In this critical period excess of the appropriate hormone or foreign molecules able to bind the receptor can cause faulty imprinting with life-long consequences. At present the imprinter effect of a molecule bound by receptor was studied in female rats at weaning. Histamine and serotonin content of blood lymphocytes and peritoneal cells (lymphocytes, mast cells and the monocyte-granulocyte-macrophage group) was measured by flow cytometry three weeks after three days treatment of three-week-old rats with the histamine and serotonin antagonist tricyclic antidepressant, mianserin. The histamine content was dramatically elevated in each cell type except blood lymphocytes. The serotonin content was also elevated in peritoneal mast cells and decreased in peritoneal lymphocytes. Considering that the measurement was done three weeks after treatment, the results call attention to the long-lasting effect of a molecule acting at receptorial level.