INFLUENCE OF INTERLEUKIN-1-BETA ON THE SECRETION OF OXYTOXIN AND VASOPRESSIN FROM THE ISOLATED RAT NEUROHYPOPHYSIS

The effect of the cytokine interleukin‐1β on the secretion of oxytocin and vasopressin from electrically stimulated rat neurohypophysis was examined in vitro. The release of oxytocin and vasopressin was concentration‐dependently increased by interleukin‐1β in the concentration range from 4.4 pM to 440 pM. The effect of interleukin‐1β on oxytocin secretion was less intense as compared to vasopressin. After 440 pM interleukin‐1β the electrically evoked release of oxytocin was increased about 22% and had not reached its maximum. The vasopressin response was maximal after 44 pM interleukin‐1β, the response being increased 43% compared to control. No trace of interleukin‐1β was found in the posterior pituitary (<350 pmol/lobe, radioimmunoassay). The results indicate that interleukin‐1β might be involved the the regulation of oxytocin and vasopressin at the pituitary level. 1990 Nordic Pharmacological Society