Blood Pressure of Sinoaortic-Denervated Dogs Is Not Increased by Cardiac Denervation

Abstract

Although blood pressure rises markedly after acute sinoaortic denervation, animals with chronic sinoaortic denervation have normal or only slightly elevated mean arterial pressures. The present study was performed to determine whether reflexes from cardiac receptors exert antihypertensive effects and thereby lower blood pressure in animals with chronic sinoaortic denervation. We made multiple measurements of blood pressures in dogs with chronic sinoaortic denervation before and after their hearts were denervated surgically. Mean arterial pressure after cardiac denervation (100.3 k 4.2 mm Hg) was not significantly different from the mean pressures recorded before cardiac denervation in these sinoaortic-denervated dogs (104.8 f 3.1 mm Hg). Also, mean heart rate after cardiac denervation (107.4 f 5.5 beats/min) did not differ significantly from the mean heart rate recorded before cardiac denervation (107.2 f 5.9 beats/min). Cardiac denervation did, however, appear to reduce the lability of both blood pressure and heart rate in sinoaorticdenervated dogs. We conclude that cardiac receptors are not responsible for maintaining arterial pressure within essentially normal limits in animals with chronic sinoaortic denervation.33

Blood pressure control in arterial‐ and cardiopulmonary receptor denervated dogs

“…baroreceptor denervation (Ferrario et al 1969, Cowley et al 1973, Ito & Scher 1981, Cornish & Gilmore 1983, Persson et al 1988, Ramirez et al 1985, Geer et al 1986, Trapani et al 1986, Alper et al 1987, Bishop et al 1987. Arterial baroreceptor denervated animals also develop hypertension during the immediate postdenervation period (Ferrario et al 1969;Cowley Correspondence: Dr Pontus B. Persson, I. Physiologisches Institut, Universitat Heidelberg, Im Neuenheimer Feld 326, D-6900 Heidelberg, W. Germany.…”

“…Arterial baroreceptor denervated animals also develop hypertension during the immediate postdenervation period (Ferrario et al 1969;Cowley Correspondence: Dr Pontus B. Persson, I. Physiologisches Institut, Universitat Heidelberg, Im Neuenheimer Feld 326, D-6900 Heidelberg, W. Germany. et al 1973, Geer et al 1986, Persson 1988), but it is controversial whether this hypertension is sustained. Some investigators found a chronic increase in arterial blood pressure (Bishop et al 1987, Ito & Scher 1981, Laubie & Schmitt 1979, whereas others observed a subsequent normalization after denervation (Cowley et al 1973, Cornish & Gilmore 1983, Ramirez et al 1985, Geer et al 1986, Saito et al 1986, Persson 1988.…”

“…et al 1973, Geer et al 1986, Persson 1988), but it is controversial whether this hypertension is sustained. Some investigators found a chronic increase in arterial blood pressure (Bishop et al 1987, Ito & Scher 1981, Laubie & Schmitt 1979, whereas others observed a subsequent normalization after denervation (Cowley et al 1973, Cornish & Gilmore 1983, Ramirez et al 1985, Geer et al 1986, Saito et al 1986, Persson 1988. Perhaps, cardiopulmonary afferents, to some extent, substitute for the lacking tonic inhibitory influence of the arterial baroreceptors, thus counteracting the augmented sympathetic tone.…”

The influence of cardiopulmonary receptors on long‐term blood pressure control and plasma renin activity in conscious dogs

“…It is important for the interpretation that these were acute experiments and that baroreceptor afferents are also interrupted by the cold-block of the vagi. With respect to the arterial baroreceptors, it is a well established fact that an acute interruption of their afferents produces a transient hypertension over the following hours (Walgenbach 1984), up to the next week (Geer et al 1986, Kezdi et al 1980. This artifact underlies cold-block investigations.…”

“…To the best of our knowledge complete, long-term denervation of the cardiopulmonary area has not been performed in conscious dogs, although others have described similar approaches denervating arterial baroreceptor (It0 & Scher 1979, Cowley et al 1980, and intersecting cardiac branches (Gregg et al 1972, Geer et al 1986, Noble et al 1972). The present study was therefore designed to investigate the longterm changes in cardiovascular function, plasma renin activity and blood volume control, before and after the complete denervation of the cardiopulmonary area.…”