title: Efficacy of clonidine in patients with essential hypertension with neurovascular contact of the rostral ventrolateral medulla.
abstract: The rostral ventrolateral medulla (RVLM) is an important center for regulation of sympathetic nerve activity. Several clinical studies have suggested an association between neurovascular contact (NVC) of RVLM and essential hypertension. Microvascular decompression (MVD) of RVLM decreases blood pressure (BP) in hypertensive patients with NVC of this region. Therefore, MVD could be a useful therapeutic strategy to reduce BP in these patients. However, as MVD is an invasive procedure, it is worthy to seek useful antihypertensive agents for hypertensive patients with NVC. It is reported that sympathetic nerve activity is elevated in patients with hypertension accompanied by NVC of RVLM. It is anticipated that sympatholytic agents could be effective in lowering BP in these patients. In this study, we investigated the efficacy of clonidine, an alpha2 adrenergic agonist, in essential hypertensives with NVC of RVLM. Thirty consecutive essential hypertensive patients with NVC and 30 consecutive essential hypertensive patients without contact were treated with clonidine for 4 weeks, and decreases in BP and plasma norepinephrine levels were compared between the two groups. Decreases in BP and plasma norepinephrine levels were significantly greater in patients with NVC than in those without contact. These results suggest that clonidine exhibits significantly greater reductions of BP and sympathetic nerve activity in essential hypertensive patients with NVC compared with those without contact of the rostral ventrolateral medulla.
authors.affiliation: Second Department of Internal Medicine, Kansai Medical University, Osaka, Japan. sakumat@hirakata.kmu.ac.jp
authors.forename: Takao
authors.initials: T
authors.lastname: Sakuma
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morimoto
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Aota
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takahashi
authors.forename: Nagaoki
authors.initials: N
authors.lastname: Toyoda
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kosaki
authors.forename: Minoru
authors.initials: M
authors.lastname: Maehara
authors.forename: Noboru
authors.initials: N
authors.lastname: Tanigawa
authors.forename: Koshi
authors.initials: K
authors.lastname: Ikeda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sawada
authors.forename: Toshiji
authors.initials: T
authors.lastname: Iwasaka
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D003000:Clonidine / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects* / Q000503:physiopathology; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000503:physiopathology; D013565:Sympatholytics / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents; D013565:Sympatholytics; D003000:Clonidine; D009638:Norepinephrine