Changes in plasma levels of serotonin and 5-hydroxyindoleacetic acid and population of serotonin-secreting cells in small and large intestine of Wistar rats in hypo- and hyperandrogenemia.

We studied the effects of hypo- and hyperandrogenemia on the plasma levels of serotonin and its major metabolite 5-hydroxyindoleacetic acid as well as on the size of EC1 cell pool in the small and large intestine of adult male Wistar rats in the control group, after orchiectomy, and after administration of long-acting testosterone Omnadren 250. Orchiectomy did not change the levels of serotonin, 5-hydroxyindoleacetic acid, and the number of AN-1-cells in the epithelium of the small and large intestine. Administration of Omnadren 250 increased serum level of free testosterone and reduced plasma serotonin concentration; the level of 5-hydroxyindoleacetic acid remained unchanged and hence the rate of serotonin metabolism increased. Hyperandrogenemia significantly reduced the number of AN-1- in the jejunum and ileum and did not change this parameter in the duodenum and colon.