Changes of Plasma and Cerebrospinal Fluid Noradrenaline during Frusemide Administration and Acute Renal Artery Constriction in Dogs

1982 ◽  
Vol 63 (s8) ◽  
pp. 343s-345s ◽  
Author(s):  
Yoshiaki Masuyama ◽  
Yuji Ueno ◽  
Mikio Arita ◽  
Hidetoshi Suruda ◽  
Osamu Mohara

1. The effects of circulating angiotensin II on cerebrospinal fluid and plasma noradrenaline during frusemide administration and acute renal artery constriction were studied in dogs. 2. The administration of frusemide produced significant increases in cerebrospinal fluid and plasma noradrenaline. Intravertebral artery infusion of [Sar1, Ala8]angiotensin II (saralasin) significantly suppressed the frusemide-induced increases in cerebrospinal and plasma noradrenaline and resulted in a fall in arterial blood pressure. 3. Acute renal artery constriction produced the marked elevation of plasma noradrenaline and arterial blood pressure, although no significant increase was found in cerebrospinal fluid noradrenaline. Though intravertebral artery infusion of saralasin did not affect cerebrospinal fluid and plasma noradrenaline, intravenous infusion of saralasin reduced the increases in arterial blood pressure and plasma noradrenaline induced by acute renal artery constriction. 4. Plasma volume was significantly reduced by frusemide administration, but unchanged by acute renal artery constriction. 5. Therefore it is suggested that circulating angiotensin II may contribute to the regulation of blood pressure at least partially by acting on the central nervous system in the sodium- and volume-depleted states. However, the renin-angiotensin system appears to play a rather direct role in the mechanism of hypertension induced by renal artery constriction, not through the action of angiotensin II on the central sympathetic nervous system.

1988 ◽  
Vol 255 (3) ◽  
pp. H483-H491 ◽  
Author(s):  
P. H. Brand ◽  
P. J. Metting ◽  
S. L. Britton

The roles of the autonomic nervous system, vasopressin, and angiotensin II in support of blood pressure were evaluated in seven conscious, resting dogs while hydrated or dehydrated. Mean arterial blood pressure (MAP) was monitored, and the dogs were given hexamethonium to block autonomic ganglia. Thirty minutes later, they were given captopril, and after another 30 min, a vasopressin V1 antagonist, d(CH2)5TyrMeAVP, was given. The order okf administration of captopril and d(CH2)5TyrMeAVP was alternated in different experiments. Hexamethonium had no effect on steady-state MAP in either hydrated or dehydrated dogs. In hydrated dogs, the average MAP was 100 mmHg; d(CH2)5TyrMeAVP decreased MAP by approximately 12 mmHg, and captopril decreased MAP by 24 mmHg. The magnitude of the effect of these two inhibitors was independent of the order of their administration. Dehydration doubled the effect of d(CH2)5TyrMeAVP on MAP but had no effect on the response to captopril. The results suggest that 1) autonomic function is not essential for maintenance of arterial blood pressure in resting dogs; 2) during autonomic ganglionic blockade, arterial blood pressure is supported by both angiotensin II and vasopressin; and 3) dehydration increases the role of vasopressin in control of blood pressure.


2016 ◽  
Vol 34 (Supplement 1) ◽  
pp. e291
Author(s):  
Seon-Ah Jin ◽  
Hee jung Seo ◽  
Sun Kyeong Kim ◽  
Gyu Yong Song ◽  
Jin-Ok Jeong

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Eisei Yamamoto ◽  
Hitoshi Takano ◽  
Hiroyuki Tajima ◽  
Jun Tanabe ◽  
Hidekazu Kawanaka ◽  
...  

Background: Renal artery stenosis (RAS) often plays an important role not only in malignant hypertension but also in sudden development of heart failure (HF) so called ‘flash pulmonary edema’ or chronic HF refractory to medical treatment. One of the possible mechanisms whereby RAS affects these unique conditions of HF is suppression of LV compliance through the complex interaction between neurohormonal systems originating from the reduction of renal blood flow. Renal artery angioplasty is expected to be an effective treatment for restoring renal blood flow in patients with RAS. The aim of the present study was whether the angioplasty can improve the impaired neurohormonal systems and diastolic cardiac function in patients with RAS. Methods: A prospective analysis was performed in 18 HF patients with RAS (age: 72±6, 3 females, NYHA I/II/III: 5/9/4) who underwent renal artery angioplasty between 2005 and 2007. Four patients with significant bilateral RAS and 3 patients with unilateral RAS in the vessel supplying a functional solitary kidney were included. We monitored the changes of biochemical and neurohormonal markers and blood pressure. Cardiac function was evaluated by tissue Doppler echocardiogram before and 3 months after the procedure. Results: Technical success was achieved in all interventions. The results are shown in table . Systolic arterial blood pressure significantly decreased by renal angioplasty. B-type natriuretic peptide (BNP) was significantly reduced 3 months after the angioplasty, whereas the change of sCr or angiotensinII was not statistically significant. Myocardial early diastolic velocity (Em), a parameter of diastolic LV function, was significantly improved compared with that measured before the procedure. Conclusions: In patients with either overt or latent HF possessing RAS, renal artery angioplasty not only decreases arterial blood pressure but also improves diastolic cardiac function in parallel with the reduction of BNP level.


1993 ◽  
Vol 265 (3) ◽  
pp. R591-R595 ◽  
Author(s):  
R. L. Thunhorst ◽  
S. J. Lewis ◽  
A. K. Johnson

Intracerebroventricular (icv) infusion of angiotensin II (ANG II) in rats elicits greater water intake under hypotensive, compared with normotensive, conditions. The present experiments used sinoaortic baroreceptor-denervated (SAD) rats and sham-operated rats to examine if the modulatory effects of arterial blood pressure on water intake in response to icv ANG II are mediated by arterial baroreceptors. Mean arterial blood pressure (MAP) was raised or lowered by intravenous (i.v.) infusions of phenylephrine (1 or 10 micrograms.kg-1 x min-1) or minoxidil (25 micrograms.kg-1 x min-1), respectively. The angiotensin-converting enzyme inhibitor captopril (0.33 mg/min) was infused i.v. to prevent the endogenous formation of ANG II during testing. Urinary excretion of water and solutes was measured throughout. Water intake elicited by icv ANG II was inversely related to changes in MAP. Specifically, rats drank more water in response to icv ANG II when MAP was reduced by minoxidil but drank less water when MAP was elevated by phenylephrine. The influence of changing MAP on the icv ANG II-induced drinking responses was not affected by SAD. These results suggest that the modulatory effects of arterial blood pressure on icv ANG II-induced drinking can occur in the absence of sinoaortic baroreceptor input.


1989 ◽  
Vol 256 (1) ◽  
pp. R112-R119 ◽  
Author(s):  
D. N. Darlington ◽  
M. Miyamoto ◽  
L. C. Keil ◽  
M. F. Dallman

The excitatory neurotransmitter, L-glutamate (0.5 M, pH 7.4), or the organic acid, acetate (0.5 M, pH 7.4), was microinjected (50 nl over 2 min) directly into the paraventricular nuclei (PVN) of pentobarbital sodium-anesthetized rats while arterial blood pressure and heart rate and plasma adrenocorticotropic hormone (ACTH), vasopressin, and oxytocin were measured. Activation of PVN neurons with L-glutamate led to increases in plasma ACTH, vasopressin, and oxytocin and a profound bradycardia (approximately 80 beats/min) with little change in arterial blood pressure. Microinjection of acetate had no effect on the above variables. The decrease in heart rate was shown to be dependent on the concentration of glutamate injected and the volume of injectate. The bradycardia was mediated through the autonomic nervous system because ganglionic blockade (pentolinium tartrate) eliminated the response; atropine and propranolol severely attenuated the bradycardia. The bradycardia was greatest when L-glutamate was microinjected into the caudal PVN. Injections into the rostral PVN or into nuclei surrounding the PVN led to small or nonsignificant decreases in heart rate. Focal electric stimulation (2-50 microA) of the PVN also led to decreases in heart rate and arterial blood pressure. These data suggest that activation of PVN neurons leads to the release of ACTH, vasopressin, and oxytocin from the pituitary and a bradycardia that is mediated by the autonomic nervous system.


1996 ◽  
Vol 271 (4) ◽  
pp. H1416-H1422 ◽  
Author(s):  
H. M. Stauss ◽  
K. C. Kregel

Power spectrum analysis of arterial blood pressure (BP) and heart rate (HR) has been used to investigate autonomic nervous system activity. Sympathetic-mediated vasomotor tone has been attributed to the BP power at frequencies between 0.05 and 0.15 Hz in humans and dogs and between 0.2 and 0.8 Hz in rats. In contrast, it has been suggested that the sympathetic nervous system is too sluggish to transmit frequencies higher than 0.017 Hz in dogs. Thus we investigated the frequency-response characteristics of the transmission of peripheral sympathetic nerve discharge to peripheral vascular resistance and arterial blood pressure in conscious rats. Eleven rats were instrumented with arterial catheters, nerve electrodes on the sympathetic splanchnic nerve, and flow probes on the superior mesenteric artery. The splanchnic nerve was cut proximal to the electrode to avoid afferent nerve stimulation. The next day the nerve was stimulated at frequencies of 0.05, 0.1, 0.2, 0.5, 1.0, and 2.0 Hz while mesenteric blood flow, BP, and HR were recorded in conscious rats. Mesenteric resistance (MR) was calculated off-line. Nerve stimulation at 0.05, 0.1, 0.2, 0.5, and 1.0 Hz significantly increased the power in MR at these respective frequencies. The greatest response was found between 0.2 and 0.5 Hz. These oscillations in MR were translated to oscillations in BP, but not in HR. Nerve stimulation on the second day, when the nerve was degenerated, did not elicit oscillations in MR or BP. We conclude that the peripheral sympathetic nervous system in rats can transmit signals at frequencies higher than those traditionally assigned to sympathetic vasomotor activity in several species, including humans, and may even overlap with the respiration-related high-frequency range.


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