DIFFERENTIAL TIME-COURSE OF ANGIOTENSIN-INDUCED AP-1 AND KROX PROTEINS IN THE RAT LAMINA TERMINALIS AND HYPOTHALAMUS

We studied the time course of expression of the inducible transcriptio n factors (ITF) c-Fos, FosB, c-Jun, JunB, JunD, Krox-20 and Krox-24, i nduced by a single intracerebroventricular injection of angiotensin II , in the subfornical organ (SFO), median preoptic nucleus (MnPO) parav entricular nucleus (PVN) and supraoptic nucleus (SON). c-Fos and Krox- 24 were expressed rapidly in neurons of all four areas but completely disappeared after 4 h. FosB showed a delayed but persistent expression between 4 h and 24 h in the MnPO and PVN. c-Jun was induced in the Mn PO, SFO and PVN after 1.5 h and in the SON after 4 h. JunB was selecti vely expressed in the MnPO and SFO and the level of JunD did not chang e. The expression of the pre-existing transcription factors SRF, ORES and ATF-2 which contribute to the transcriptional control of jun, fos and krox genes, was not affected by Ang II. Thus, we could show for th e first time that an acute stimulation of AT receptors results in cont inual changes in ITF expression over 24 h. (C) 1998 Published by Elsev ier Science Ireland Ltd.