Effects of droperidol on systemic blood pressure, heart rate and renal nerve activity in anesthetized rabbits

1992 ◽  
Vol 37 (1) ◽  
pp. 70
Author(s):  
Masayuki Aibiki ◽  
Shinji Ogura ◽  
Yoichi Shirakawa ◽  
Keisuke Honda ◽  
Osamu Umegaki ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systemic Blood Pressure ◽  
Systemic Blood ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Renal Nerve Activity

Aging is not accompanied by sympathetic hyperresponsiveness to air-jet stress

1996 ◽  
Vol 271 (2) ◽  
pp. H768-H775 ◽  
Author(s):  
H. M. Stauss ◽  
D. A. Morgan ◽  
K. E. Anderson ◽  
M. P. Massett ◽  
K. C. Kregel
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Low Frequency ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Renal Sympathetic Nerve Activity ◽  
Fischer 344 ◽  
Air Jet ◽  
Renal Nerve Activity ◽  
Renal Sympathetic

It has been postulated that sympathetic nervous system reactivity to acutely applied stress is increased with age. We investigated the autonomic and hemodynamic adjustments to air-jet stress in 9 mature (12-mo-old) and 11 senescent (24-mo-old) Fischer 344 rats. Rats were instrumented with arterial and venous catheters, flow probes around the renal artery, and nerve electrodes on the ipsilateral renal nerve. After the rats recovered from surgery, blood pressure, heart rate, renal blood flow, and renal sympathetic nerve activity were recorded during control conditions and during an 8-min continuous air-jet application. Renal resistance and the low (0.01-0.20 Hz)- and mid-frequency (0.20-0.50 Hz) power of blood pressure were computed off-line. The air jet induced an increase in blood pressure, heart rate, renal resistance, renal nerve activity, and blood pressure power in the low- and mid-frequency ranges in both groups. Blood pressure and low-frequency blood pressure power increased less, and the elevations in renal resistance and renal nerve activity were of shorter duration in senescent compared with mature rats. These data suggest that sympathetic responsiveness to air-jet stress is not enhanced with increasing age.

Inhibitory effect of renal nerve activity during canine anaphylactic hypotension

1990 ◽  
Vol 258 (2) ◽  
pp. R383-R387 ◽  
Author(s):  
S. Koyama ◽  
T. Fujita ◽  
H. Uematsu ◽  
T. Shibamoto ◽  
M. Aibiki ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systemic Blood Pressure ◽  
Inhibitory Effect ◽  
Baroreceptor Reflex ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Vagal Nerves ◽  
Renal Nerve Activity ◽  
Anesthetized Dogs ◽  
Reflex Control

We have examined baroreceptor regulation of renal nerve activity (RNA) during anaphylactic hypotension that affects renal nerve activity. In anesthetized dogs, mean blood pressure (MBP), heart rate (HR), and RNA were simultaneously measured. To test for a normally functioning baroreceptor reflex in each animal, a transient hypotension was induced by an intravenous injection of sodium nitroprusside (4 micrograms/kg). Nitroprusside produced a reflex increase in RNA (+63 +/- 12% at -20 mmHg and +139 +/- 8% at -40 mmHg) and HR (+13 +/- 1 beats/min at -20 mmHg and +21 +/- 2 beats/min at -40 mmHg). However, intravenous administration of Ascaris suum antigen in animals with an intact neuraxis caused a decrease in RNA (-15 +/- 14% at -20 mmHg and -42 +/- 11% at -40 mmHg blood pressure during the antigen-induced hypotension) in parallel with a fall in systemic blood pressure. HR responses were -5 +/- 2 beats/min at -20 mmHg and -10 +/- 1 beats/min at -40 mmHg during the hypotension induced by the antigen. In animals with combined denervation of the carotid sinus and vagal nerves, HR did not change significantly during anaphylactic hypotension. However, a decrease in RNA remained (-60 +/- 4% at -20 mmHg and -72 +/- 4% at -40 mmHg of hypotension). The decrease in RNA after antigen administration was significantly greater after denervation than in animals with an intact neuraxis. These results indicate that systemic baroreceptor reflex control of RNA is reduced during anaphylactic hypotension. Impaired reflex control of sympathetic nerve activity may result from an impairment of sympathetic outflow through the central nervous system.

Cardiopulmonary sympathetic afferent influences on renal nerve activity

1977 ◽  
Vol 233 (5) ◽  
pp. H592-H599 ◽  
Author(s):  
L. C. Weaver
Keyword(s):  
Blood Pressure ◽  
Volume Expansion ◽  
Systemic Blood Pressure ◽  
Electrical Stimulus ◽  
Renal Nerves ◽  
Intravascular Volume ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Afferent Nerves ◽  
Renal Nerve Activity

Cardiopulmonary sympathetic afferent nerves may affect renal control of intravascular volume by influencing renal sympathetic nerve activity. This influence was evaluated in alpha-chloralose anesthetized, vagotomized, sino-aortic denervated cats. When the afferent nerves were activated with a single electrical stimulus, the renal nerve responded with an excitatory burst of activity followed by a long period of inhibition. This response had characteristics of a supraspinal reflex. Repetitive stimulation of the sympathetic afferent nerve either inhibited or excited renal nerves and increased or decreased systemic blood pressure. The direction of these changes depended on stimulus parameters. No obligatory correlation in the direction of change of nerve activity and blood pressure was observed. Activation of cardiopulmonary sympathetic afferent nerves by intravascular volume expansion inhibited renal nerve discharge. Inhibition was elminated by sectioning the sympathetic afferent nerves. Volume expansion had no effect on lumbar sympathetic discharge monitored simultaneously with renal nerve activity. This observation suggests specificity of reflex influences of these afferent nerves on the kidney. In conclusion, cardiopulmonary sympathetic afferent nerves can reflexly alter renal nerve activity, and therefore may affect renal control of intravascular volume.

scholarly journals Changes in Respiratory Rate, Blood Pressure and Heart Rate Variability in Rabbits during Orthostasis

2006 ◽  
Vol 75 (1) ◽  
pp. 3-12 ◽  
Author(s):  
J. Mokrý ◽  
T. Remeňová ◽  
K. Javorka
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Respiratory Rate ◽  
Supine Position ◽  
Spectral Power ◽  
Systemic Blood Pressure ◽  
Microcomputer System ◽  
Systemic Blood ◽  
Frequency Bands

The purpose of the study was to evaluate the changes of respiratory rate, systemic blood pressure and heart rate variability parameters (HRV) during orthostasis in anaesthetized rabbits. Furthermore, these changes were influenced by affecting the renin-angiotensin-aldosterone (RAA) system and autonomic nervous system (ANS) to study the mechanisms participating in activity of spectral frequency bands of HRV in rabbits. Ten adult rabbits (Chinchilla) were anaesthetized by ketamine and flunitrazepam. The systemic blood pressure, tidal volume and respiratory rate were measured. HRV was evaluated by microcomputer system VariaPulse TF3E. The R-R intervals were derived from the electrocardiogram signal from subcutaneous needle electrodes. The evaluation of HRV in very low (VLF; 0.01-0.05 Hz), low (LF; 0.05-0.15 Hz) and high frequency bands (HF; 0.15-2.0 Hz) was made and parameters of frequency and time analysis were calculated. The measurements were made in horizontal (supine) position, in orthostasis (the angle of 60 °) and again in supine position before and after enalapril (0.5 mg/kg b.w.), metipranolol (0.2 mg/kg b.w.), and after subsequent bilateral cervical vagotomy. The orthostasis in anaesthetized rabbits is accompanied by depression of respiratory rate reversed only by vagotomy. Furthermore, decrease of systemic blood pressure, unchanged heart rate and increased characteristics of heart rate variability were found, with predominant increase of spectral power in LF and VLF bands. This elevation can be eliminated only by complete blockade of ANS. Although the participation of ANS or RAA system in modification of individual HRV frequency bands is not as specific as in humans, we confirmed the participation of RAA system in determination of the VLF band.

Neural mechanism underlying basilar arterial constriction by intracisternal L-NNA in anesthetized dogs

1993 ◽  
Vol 265 (1) ◽  
pp. H103-H107 ◽  
Author(s):  
N. Toda ◽  
K. Ayajiki ◽  
T. Okamura
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cerebral Arteries ◽  
Neural Mechanism ◽  
Systemic Blood Pressure ◽  
Systemic Blood ◽  
Anesthetized Dogs ◽  
Arterial Constriction ◽  
Synthase Inhibitor

Basilar arterial diameters were angiographically measured in anesthetized dogs in which systemic blood pressure and heart rate were also monitored. Injections of NG-nitro-L-arginine (L-NNA), a NO synthase inhibitor, into the cisterna magna produced a significant, persistent decrease in arterial diameter, the effect being reversed by intracisternal injections of L-arginine. The vasoconstrictor effect of L-NNA was diminished in dogs treated with hexamethonium. On the other hand, treatment with phentolamine in a dose sufficient to lower blood pressure to a level similar to that attained with hexamethonium did not inhibit, but rather potentiated, the effect of intracisternal L-NNA. Nicotine injected into the vertebral artery significantly dilated the basilar artery. The effect was abolished by treatment with L-NNA applied intracisternally, the inhibition being reversed by the addition of L-arginine. Systemic blood pressure and heart rate were not altered by intracisternally applied L-NNA and L-arginine. These findings support the hypothesis that basilar arterial constriction caused by intracisternal L-NNA is associated with a suppression of NO synthesis in nitroxidergic nerves innervating the cerebroarterial wall rather than an elimination of basal release of NO from the endothelium. Functional importance of nitroxidergic vasodilator innervation in cerebral arteries in vivo is thus clarified.

Factors causing natriuresis after hypothalamic injection of a cholinergic drug in rats

1983 ◽  
Vol 244 (1) ◽  
pp. F64-F69 ◽  
Author(s):  
C. R. Silva-Netto ◽  
R. H. Jackson ◽  
R. E. Colindres
Keyword(s):  
Blood Pressure ◽  
Renal Plasma Flow ◽  
Cholinergic Stimulation ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Conscious Rats ◽  
Clearance Studies ◽  
Renal Nerve Activity ◽  
Stimulation Of ◽  
Cholinergic Drug

We investigated possible mechanisms for the natriuresis seen after injection of the cholinergic drug carbamylcholine chloride (carbachol) into the lateral hypothalamus of conscious rats. In unrestrained rats injection of 1 microgram of carbachol in 1 microliter of 0.15 M NaCl solution through a permanently implanted cannula produced a significant natriuresis and kaliuresis. Injection of vehicle produced no changes. The same animals were then subjected to bilateral renal denervation (n = 13) or sham denervation (n = 13) and injected with the same solutions 1 wk later. Carbachol injection produced a natriuresis (P less than 0.0001) and a kaliuresis (P less than 0.01) in all animals studied. Both responses were of a magnitude similar to the responses seen before denervation. We studied other rats while awake but restrained, which permitted the performance of clearance studies and blood pressure measurements. Injection of carbachol produced diuresis, natriuresis, and kaliuresis in all rats, with no change in p-aminohippurate clearance and only transient change in inulin clearance. An increase in blood pressure occurred in some but not all rats. The response in rats with bilaterally denervated kidneys (n = 7) was similar to that of rats with innervated kidneys (n = 5). The natriuresis seen after cholinergic stimulation of the hypothalamus in conscious rats is not primarily mediated by inhibition of renal nerve activity and can be dissociated from changes in blood pressure, glomerular filtration rate, and renal plasma flow.

Baroreceptor influence on postural changes in blood pressure and carotid blood flow

1963 ◽  
Vol 205 (2) ◽  
pp. 360-364 ◽  
Author(s):  
Francis L. Abel ◽  
John H. Pierce ◽  
Warren G. Guntheroth
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Sinus ◽  
Systemic Blood Pressure ◽  
Systemic Blood ◽  
Carotid Blood Flow ◽  
Postural Changes ◽  
Nembutal Anesthesia

The effects of 30° head-down and head-up tilting on mean systemic blood pressure, carotid blood flow, and heart rate were studied in 16 dogs under morphine and Nembutal anesthesia. The tilting procedure was further repeated after denervation of the carotid sinus and aortic arch baroreceptors and after administration of a dihydrogenated ergot alkaloid mixture (Hydergine). The results indicate that the drop in pressure in the head-down position is primarily due to baroreceptor activity and that the baroreceptors are necessary for compensatory vasoconstriction on head-up tilting. Carotid blood flow decreased in both tilted positions in the control animals; the possible relationship to cerebral blood flow is discussed.

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