[Involvement of habenula nucleus in the pathogenesis of stress induced hypertension and the underlying mechanisms].
Stress-induced hypertension (SIH) was performed by electric shock on hind paw in rats. Habenula(Hb) lesion decreased the degree of SIH. After stress, the Ang II concentration in blood plasma and in Hb were increased. BP was elevated after icv or MHb administration of Ang II, and decreased after microinjection of saralasin into MHb. The BP changes induced by Ang II and saralasin were more prominent in SIH than in normotensive rats. Iontophoresis of AngII (or saralasin) into Hb increased (or decreased) the discharges of the excitatory neurons related to cardiovascular activity. Ang II could inhibit the activity of Ik channel. Using the same methods, the actions of L-NNA and SNP were investigated. From above, it is suggested that Hb is involved in the development of SIH. Stress stimulus strengthened the sensitivity of Hb, especially MHb to AngII, and also induced in increase of AngII. These changes would promote the response of sensitized Hb in the development of SIH.
Cui
J J
JJ
Department of Physiology, Norman Bethune University of Medical Sciences, Changchun 130021.
D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D004558:Electric Stimulation; D019262:Habenula / Q000503:physiopathology*; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D009474:Neurons / Q000502:physiology; D051381:Rats; D012504:Saralasin / Q000494:pharmacology; D013312:Stress, Physiological / Q000503:physiopathology*
D000804:Angiotensin II; D012504:Saralasin