IMMEDIATE-EARLY GENES IN BLOOD-PRESSURE REGULATION

The immediate early genes c-fos and c-jun are transcription regulating factors. c-fos expression is widely used as a marker of neuronal acti vation and has been used in this study to identify those neurons, pres umably vasomotor neurons, that are activated after interventions that alter blood pressure. c-fos and c-jun are expressed in the rostral ven tral medulla (RVM) when the tonically active inhibitory inputs to the RVM are removed, either acutely or chronically, as in the SHR model of genetic hypertension. The injection of antisense oligonucleotide comp lementary to c-fos mRNA in the RVM attenuates the expression of c-fos, lowers resting blood pressure and attenuates blood pressure responses that are evoked via RVM mechanisms. These studies suggest a link betw een immediate early gene expression in neurons in the RVM and the regu lation of blood pressure. c-fos could have an important role in regula ting the activity of these central cardiovascular neurons. The role of the immediate early gene c-jun in cardiovascular control remains to b e elucidated.