Sl. Bealer et So. Abell, PARAVENTRICULAR NUCLEUS HISTAMINE INCREASES BLOOD-PRESSURE BY ADRENOCEPTOR STIMULATION OF VASOPRESSIN RELEASE, American journal of physiology. Heart and circulatory physiology, 38(1), 1995, pp. 80-85
The role of adrenoreceptor stimulation and the peripheral mechanism me
diating the increase in mean arterial blood pressure (MAP) and heart r
ate (HR) during administration of histamine (HA) in the paraventricula
r nucleus/anterior hypothalamus (PVN/AH) was evaluated in conscious ra
ts. HA administered through microdialysis probes in the PVN/AH region
increased MAP (18 +/- 1 mmHg) and HR (81 +/- 10 beats/min). The presso
r response was abolished by simultaneous administration of phentolamin
e (alpha(1)- and alpha(2)-antagonist) or prazosin (alpha(1)-antagonist
) but not altered by yohimbine (alpha(2)-antagonist). The tachycardia
was not effected by any adrenergic antagonist. Furthermore, ganglionic
blockade did not reduce the increase in MAP (21 +/- 2 mmHg) during PV
N/AH perfusion with HA, while V-1-vasopressin receptor blockade abolis
hed the presser response (4 +/- 2 mmHg). These data suggest that HA ad
ministered to the PVN/AH increases blood pressure by local release of
norepinephrine and alpha(1)-adrenoreceptor stimulation of vasopressin
secretion, while the tachycardia is not mediated by alpha-adrenorecept
ors.