Association between increased serotonin metabolism in rat brainstem nuclei and development of spontaneous hypertension.

Spontaneously hypertensive rats have increased brain stem serotonin turnover localized to the nuclei raphe magnus, raphe pallidus, tractus solitarius and reticularis lateralis. It occurs only in young animals coinciding with the development of hypertension. In the locus coeruleus, increased serotonin metabolism is present during both the early and the established phase of hypertension. Our results provide evidence for serotonergic overactivity in specific brainstem nuclei during the development of spontaneous hypertension in the rat.