TABLE 5.   Acute effects of cytokines on the HPA axis of laboratory animals Cytokine Route Effect Reference No. IL-1 iv   CRF in portal blood 223, 525, 574, 629, 730  Plasma ACTH, corticosterone ip   CRF mRNA 639, 640, 824    CRF content of ME   POMC mRNA in anterior pituitary Plasma ACTH icv Plasma ACTH 574, 695  IL-1 iv   PVN c-fos mRNA or Fos protein 55, 223, 237, 525, 527, 560, 824, 929, 932, 936, 940    PVN CRF mRNA   CRF secretion from ME   CRF content of ME Plasma ACTH, corticosterone ip   PVN c-fos mRNA or Fos protein 63, 64, 70, 98, 187, 327, 466, 628, 686, 690, 752, 824   CRF PVN mRNA   POMC mRNA in anterior pituitary   POMC hnRNA in anterior pituitary   ACTH content of anterior pituitary Plasma ACTH, corticosterone icv   PVN c-fos mRNA or Fos protein 40, 187, 457, 681, 684, 692    PVN CRF mRNA   PVN AVP mRNA   CRF secretion from ME Plasma ACTH, corticosterone IL-2 iv ACTH 574 icv   Electrical activity of PVN neurons 76, 317  Plasma ACTH*, corticosterone* ip   POMC in anterior pituitary 326, 623    Hypothalamic vasopressin mRNA Hypothalamic oxytocin mRNA IL-4 ip POMC in anterior pituitary 326 IL-6 iv   PVN Fos protein 527, 575, 589, 909  Plasma ACTH, corticosterone ip Plasma ACTH, corticosterone 52, 327  icv Plasma ACTH, corticosterone 499, 527, 859, 909  IL-11 ip Plasma corticosterone 52 IL-12 ip Plasma corticosterone 608 LIF ia Plasma ACTH 5 ip Plasma corticosterone 52 OM ip Plasma corticosterone 52 CT-1 ip Plasma corticosterone 52 CNTF ip Plasma corticosterone 52, 246  TNF- iv   CRF secretion from ME 58, 66, 223, 771, 772, 938  Plasma ACTH, corticosterone icv Plasma ACTH 51, 673, 881  IFN- ip, icv or  Plasma corticosterone 725, 726, 729  Activin icv   CRF in portal blood 650 Plasma ACTH EGF iv Plasma ACTH, corticosterone 492, 551  icv Plasma ACTH, corticosterone 551 NGF iv Plasma ACTH, corticosterone 618, 741, 836  SCF iv   PVN Fos protein 435 Plasma ACTH, corticosterone Routes of administration: iv, intravenous; ia, intra-arterial; ip, intraperitoneal; icv, intracerebroventricular. PVN, paraventricular nucleus; ME, median eminence; POMC, proopiomelanocortin. Other definitions are as in Table 3. * Chronic (7-day) infusion. Significant increases in plasma ACTH concentration observed only during latter period of dark cycle. At doses tested, each of these cytokines alone had no effect on plasma corticosterone, but each potentiated the corticosterone response to a submaximal dose of IL-1. Stimulation of corticosterone secretion was noted only at higher doses of IFN-.