Central catecholaminergic responses in hypoxie moderation of spontaneous hypertension

Normobaric hypoxia conditioning reduces blood pressure and normalizes nitric oxide synthesis in patients with arterial hypertension

“…The results of multiple studies on protective effects of intermittent hypoxia suggest other mechanisms, including improved O 2 delivery and utilization in tissues [38], IHC-induced increases in sodium and water excretion [7], increased parasympathetic [39] and decreased sympathetic nervous activity [40][41][42], reduction of peripheral vascular resistance [43], potentiation of antioxidant defense due to increased activity of antioxidant enzymes [44], and prevention of vessel rarefaction, especially in brain and skeletal muscles [45,46], due to increased expression of vascular endothelial growth factor [47]. As any long-term, effective antihypertensive treatment can improve endothelial function, including enhancement of eNOS activity [48,49], the reduction of BP induced by these antihypertensive mechanisms may by itself serve to normalize nitric oxide metabolism.…”

Intermittent Hypoxia: Cause of or Therapy for Systemic Hypertension?

“…While hypoxia regimens that model OSA lead to sustained increases in sympathetic activity and vasoreactivity (12,159,160), other hypoxia protocols attenuate both basal and stress-induced sympathetic activity in rats (161,162). Henley and Bellush (145,163) reported that attenuation of hypertension was nearly complete when altitude exposure (simulated altitude of ;3700 m for 21 d) was initiated in 4-5-wk old SHR. Non-hypoxia-conditioned SHR had appreciably higher norepinephrine (NE) contents in hypothalamus, brainstem and frontal cortex, relative to Wistar-Kyoto (WKY) rats (145).…”

“…Henley and Bellush (145,163) reported that attenuation of hypertension was nearly complete when altitude exposure (simulated altitude of ;3700 m for 21 d) was initiated in 4-5-wk old SHR. Non-hypoxia-conditioned SHR had appreciably higher norepinephrine (NE) contents in hypothalamus, brainstem and frontal cortex, relative to Wistar-Kyoto (WKY) rats (145). Hypoxia exposure of SHR decreased NE content in all three brain regions, in association with reduced NE turnover.…”