Lesions of the lateral parabrachial nucleus (LPBN) impair blood pressure recovery after hypotensive blood loss (Am J Physiol Regul Integr Comp Physiol 280: R1141, 2001). This study tested the hypothesis that posthemorrhage blood pressure recovery is mediated by activation of neurons, located in the ventrolateral aspect of the LPBN (VL-LPBN), that initiates blood pressure recovery by restoring s...

This paper is concerned with the effect of exercise on the blood pressure and the modification of this effect by hexamethonium bromide. It is well known that the methonium compounds can produce a fall in the blood pressure ofmany hypertensive subjects when lying down. This fall, however, is variable and inconstant. In normal persons, the methonium compounds do not produce a fall in the basal bl...

Our previous finding that dexamethasone-induced hypertension in rats is associated with enhanced reactivity of mesenteric arteries to arginine vasopressin but not to angiotensin II (Ang II) or norepinephrine has led us to postulate that vasopressin contributes to the development or maintenance of glucocorticoid-induced hypertension. To test this view, we investigated the effects of vasopressin,...

During the past five years ganglion-blocking agents have been used extensively in the treatment of arterial hypertension. The discovery of the activity of hexamethonium by Paton and Zaimis (1949) placed at our disposal an active therapeutic agent capable of producing a substantial reduction in the blood pressure. Subsequent research has been directed to the synthesis of new drugs offering advan...

Probably the first studies of the pharmacology of quaternary ammonium compounds were made by Crum-Brown and Fraser in 1868. Burn and Dale (1915) found that, unlike nicotine, tetraethyl-ammonium chloride blocked autonomic ganglia without noticeable initial stimulation. Barlow and Ing (1948a and b), Paton and Zaimis (1948a and b), and Balaban et al. (1949) studied the properties of some chemical ...

This study represents an effort to distinguish between neurogenic and humoral vasoconstrictive factors in a representative group of hypertensive patients by the response to hexamethonium ganglionic blockade. The correlation between intravenous hexamethonium sensitivity and subsequent treatment response was also determined. O~NE of the most difficult problems in essential hypertension is to sele...

In the present study we examined sympathetic function and baroreceptor reflex sensitivity in adult spontaneously hypertensive rats (SHR) after a selective transection of afferent renal nerves in the prehypertensive and established phases of hypertension. Renal deafferentation performed between 3 and 4 weeks after birth did not influence the course of the development of high blood pressure when ...

Ganglion-blockers, such as tetra-ethylammonium (TEA) and hexamethonium, enhance responsiveness to vasoactive agents, both pressor and depressor (1). In dogs, the renal arterial bed seems to contribute to the change in blood pressure response since, after giving TEA, adrenaline causes a larger increase and isopropylnoradrenaline (Isuprel@) a larger decrease in renal vascular resistance than in t...

To determine whether the release of endothelium-derived relaxing factor (EDRF) is sympathetically mediated, we studied the effects of beta-blockade by propranolol, ganglionic blockade with hexamethonium, or mechanical pithing on the blood pressure response to EDRF inhibition in anesthetized rats. We inhibited EDRF with 10 mg/kg of either NG-monomethyl-L-arginine (L-NMMA) or N omega-nitro-L-argi...

Hexamethonium bromide in normotensive and renal hypertensive dogs resulted in significant reductions in arterial blood pressure, cardiac output and cardiac work. Ihe decrease in cardiac output relative to that in blood pressure suggests that the blood pressure reduction was largely due to the decrease in cardiac output. There was a decrease in coronary flow accompanied by an increase in myocard...