Melatonin Decreases Brain Serotonin Release, Arterial Pressure and Heart Rate in Rats

Pharmacology ◽  
1993 ◽  
Vol 47 (2) ◽  
pp. 91-97 ◽  
Author(s):  
Jih I. Chuang ◽  
Shen S. Chen ◽  
Mao T. Lin
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Serotonin Release ◽  
Brain Serotonin

Effect of brain 5-hydroxytryptamine alterations on reflex bradycardia in rats

1979 ◽  
Vol 236 (5) ◽  
pp. R302-R306
Author(s):  
M. T. Lin ◽  
S. I. Chern
Keyword(s):  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Previous Treatment ◽  
Intravenous Dose ◽  
Brain Serotonin ◽  
Insignificant Change ◽  
Decarboxylase Inhibition ◽  
Reflex Bradycardia

The vasopressor and bradycardia responses to an intravenous dose of epinephrine were assessed in saline-controlled, 5-hydroxytryptamine-(5-HT) depleted, and 5-HT-potentiated rats. Regardless of the previous treatment epinephrine produced an insignificant change in the basal levels of mean arterial pressure and heart rate. However, brain serotonin alteration did produce some influences on the reflex bradycardia in response to an elevation in arterial pressure. Elevating 5-HT contents in brain with 5-hydroxytryptophan (5-HTP) after peripheral decarboxylase inhibition with Ro 4-4602 produced a significant reduction in reflex bradycardia compared to the controls. In contrast, depleting 5-HT contents in brain with either p-chlorophenylalanine (PCPA) or 5,7-dihydroxytryptamine (5,7-DHT) led to an enhancement of epinephrine-induced bradycardia. Moreover, the enhanced reflex bradycardia induced by PCPA treatment was readily blocked by the replacement of the depleted brain 5-HT with 5-HTP and Ro 4-4602. The results suggest that serotoninergic systems play a role in the elaboration or modulation of reflex bradycardia. Specifically, 5-HT appears to inhibit reflex bradycardia since its depletion facilitated and its elevation inhibited reflex bradycardia.

Electrical stimulation of the carotid sinus lowers arterial pressure and improves heart rate variability in l-NAME hypertensive conscious rats

2020 ◽  
Vol 43 (10) ◽  
pp. 1057-1067 ◽  
Author(s):  
Gean Domingos-Souza ◽  
Fernanda Machado Santos-Almeida ◽  
César Arruda Meschiari ◽  
Nathanne S. Ferreira ◽  
Camila A. Pereira ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Electrical Stimulation ◽  
Arterial Pressure ◽  
Carotid Sinus ◽  
Conscious Rats ◽  
Stimulation Of

scholarly journals Arterial Pressure, Heart Rate, and Cerebral Hemodynamics Across the Adult Life Span

Hypertension ◽  
2017 ◽  
Vol 69 (4) ◽  
pp. 712-720 ◽  
Author(s):  
Chang-Yang Xing ◽  
Takashi Tarumi ◽  
Rutger L. Meijers ◽  
Marcel Turner ◽  
Justin Repshas ◽  
...  
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Life Span ◽  
Adult Life ◽  
Cerebral Hemodynamics ◽  
Adult Life Span

scholarly journals Effect of Dexmedetomidine on Perioperative Stress Response and Immune Function in Patients With Tumors

2020 ◽  
Vol 19 ◽  
pp. 153303382097754
Author(s):  
Lihong Zheng ◽  
Juan Zhao ◽  
Likun Zheng ◽  
Shuangfeng Jing ◽  
Xiaoting Wang
Keyword(s):  
Heart Rate ◽  
Stress Response ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Immune Function ◽  
Spontaneous Respiration ◽  
General Anesthetics ◽  
Ifn Γ ◽  
Group D ◽  
Perioperative Stress

Objective: This study aims to investigate the effect of dexmedetomidine on perioperative stress response and immune function in patients with tumors. Methods: Sixty patients who underwent selective radical gastrectomy for cancer were randomly divided into 3 groups: remifentanil group (group R), dexmedetomidine group (group D), and sufentanil group (group S). Remifentanil, dexmedetomidine, and sufentanil were used as general anesthetics. Endotracheal intubation and mechanical ventilation were performed after the spontaneous respiration disappeared. Then, the data were recorded, and blood samples were collected at all time points. Results: The heart rate significantly increased ( P < 0.05) at T1 in group S, and both heart rate and mean arterial pressure significantly increased ( P < 0.05) in group R when compared to group D. The heart rate significantly increased ( P < 0.05) at T2 in group S and group R. Furthermore, the heart rate significantly increased ( P < 0.05) at T3 and T4 in group S and group R. Intra-group comparison: The heart rate at T1–T4 and mean arterial pressure at T1–T4 significantly increased ( P < 0.05) in group S, and the heart rate at T1 and T4, and mean arterial pressure at T2–T4 significantly increased ( P < 0.05) in group R when compared to T0. The serum IL-6, IFN-γ, and β-EP significantly increased ( P < 0.05) at T0’ in group S and group R when compared to group D. Blood glucose, and serum IL-10, IFN-γ, and β-EP significantly increased ( P < 0.05), while IL-18 significantly decreased ( P < 0.05) at T1’ in group S and group R. Conclusion: Continuous infusion of dexmedetomidine in combination with the inhalation of sevoflurane is superior to sevoflurane + remifentanil or sufentanil in patients undergoing tumor surgery.

scholarly journals Preclinical Pharmacology in the Rhesus Monkey of CW 1759-50, a New Ultra-short Acting Nondepolarizing Neuromuscular Blocking Agent, Degraded and Antagonized by L-Cysteine

2018 ◽  
Vol 129 (5) ◽  
pp. 970-988 ◽  
Author(s):  
John J. Savarese ◽  
Hiroshi Sunaga ◽  
Jeff D. McGilvra ◽  
Matthew R. Belmont ◽  
Matthew T. Murrell ◽  
...  
Keyword(s):  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Neuromuscular Blockade ◽  
Blocking Agent ◽  
Neuromuscular Blocking ◽  
Neuromuscular Blocking Agent ◽  
Duration Of Action ◽  
Short Acting ◽  
Circulatory Effects

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Structure–activity studies were performed to identify a new neuromuscular blocking agent retaining the ultra-short acting characteristics of gantacurium, including degradation and reversal by l-cysteine, but lacking its histaminoid properties in man. CW 1759-50 has emerged from this program. Methods Adduction of CW 1759-50 with l-cysteine was studied by high-performance liquid chromatography and mass spectrometry. Institutional Animal Care and Use Committee–approved comparisons of CW 1759-50 to gantacurium were performed in rhesus monkeys. ED95 for neuromuscular blockade was established. Spontaneous recovery was compared to reversal by l-cysteine in paired studies of boluses or infusions. In addition, changes in mean arterial pressure and heart rate after very large doses of 15 to 60 × ED95 were compared. Results The half-time of adduction of l-cysteine to CW 1759-50 in vitro was 2.3 min. The ED95 of CW 1759-50 was 0.069 ± 0.02 mg/kg; ED95 of gantacurium was 0.081 ± 0.05 mg/kg (P = 0.006). Duration of action (recovery to 95% twitch height after 98 to 99% blockade) was as follows: CW 1759-50, 8.2 ± 1.5 min; and gantacurium, 7.4 ± 1.9 min; (n = 8 and 9, P = 0.355). Administration of l-cysteine (30 mg/kg) shortened recovery (i.e., induced reversal) from CW 1759-50 after boluses or infusions (P always less than 0.0001). Recovery intervals (5 to 95% twitch) ranged from 6.1 to 6.7 min (and did not differ significantly) after boluses of 0.10 to 0.50 mg/kg, as well as control infusions (P = 0.426 by analysis of variance). Dose ratios comparing changes of 30% in mean arterial pressure or heart rate to ED95 for neuromuscular blockade (ED 30% Δ [mean arterial pressure or heart rate]/ED95) were higher for CW 1759-50 than for gantacurium. Conclusions CW 1759-50, similar to gantacurium, is an ultra-short acting neuromuscular blocking agent, antagonized by l-cysteine, in the monkey. The circulatory effects, however, are much reduced in comparison with gantacurium, suggesting a trial in humans.

Additive Interactions between Propofol and Ketamine When Used for Anesthesia Induction in Female Patients 

1995 ◽  
Vol 82 (3) ◽  
pp. 641-648 ◽  
Author(s):  
T. W. Hui ◽  
T. G. Short ◽  
W. Hong ◽  
T. Suen ◽  
T. Gin ◽  
...  
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Additional Term ◽  
Anesthesia Induction ◽  
Response Curves ◽  
Intravenous Anesthesia ◽  
Verbal Command ◽  
Female Patients ◽  
Loss Of Response ◽  
Significant Difference

Background Propofol and ketamine may be paired for anesthesia induction and for total intravenous anesthesia. The nature of any sedative interactions occurring between propofol and ketamine are unknown. The combination when used for anesthesia induction in female patients was studied. Methods Quantal dose-response curves were determined in 180 female patients to whom the drugs were administered individually and in combination. Two minutes after administering the drugs, two endpoints were assessed. First, loss of response to verbal command (hypnosis) and then, in those who failed to respond to this endpoint, loss of response to a 5-s transcutaneous tetanus (anesthesia). Interactions were analyzed by fitting the data to a mathematical model in which response was analyzed in terms of the doses of the two drugs and an additional term included to describe nonadditive interactions. The incidences of apnea, arterial pressure, and heart rate changes during the first 5 min were recorded. Results At the hypnotic endpoint, the ED50s were 1.10 mg/kg propofol (95% CIs 0.93-1.27), 0.39 mg/kg ketamine (95% CIs 0.27-0.46), and the combination of 0.63 mg/kg propofol and 0.21 mg/kg ketamine (95% CIs 0.53/0.18-0.73/0.24). At the anesthetic endpoint, the ED50s were 1.85 mg/kg propofol (95% CIs 1.58-2.36) 0.66 mg/kg ketamine (95% CIs 0.58-0.77), and the combination of 1.05 mg/kg propofol and 0.35 mg/kg ketamine (95% CIs 0.88/0.29-1.27/0.42). The effects were additive at both endpoints; there was no evidence of an interaction. The ED50s for apnea were 1.61 mg/kg propofol (95% CIs 1.39-1.94), greater than 0.85 mg/kg ketamine and for the combination 1.50 mg/kg propofol and 0.50 mg/kg ketamine (95% CIs 1.15/0.38-3.09/1.03). The addition of ketamine did not significantly alter the ED50 for apnea of propofol. There was a significant difference in the arterial pressures among the three groups (P &lt; 0.001). Using the combination, the cardiostimulant effects of ketamine balanced the cardiodepressant effects of propofol. There was no change in arterial pressure or heart rate after the noxious stimulus. Conclusions When using the combination, doses were additive at hypnotic and anesthetic endpoints. Ketamine had no influence on the incidence of apnea after propofol, and the net hemodynamic effects were minimal.

Hypotensive and Regional Haemodynamic Effects of Exercise, Fasted and after Food, in Human Sympathetic Denervation

1998 ◽  
Vol 94 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Sharmini Puvi-Rajasingham ◽  
Gareth D. P. Smith ◽  
Adeola Akinola ◽  
Christopher J. Mathias
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Superior Mesenteric Artery ◽  
Vascular Resistance ◽  
Mesenteric Artery ◽  
Autonomic Failure ◽  
Sympathetic Denervation ◽  
Stroke Distance

1. In human sympathetic denervation due to primary autonomic failure, food and exercise in combination may produce a cumulative blood pressure lowering effect due to simultaneous splanchnic and skeletal muscle dilatation unopposed by corrective cardiovascular reflexes. We studied 12 patients with autonomic failure during and after 9 min of supine exercise, when fasted and after a liquid meal. Standing blood pressure was also measured before and after exercise. 2. When fasted, blood pressure fell during exercise from 162 ± 7/92 ± 4 to 129 ± 9/70 ± 5 mmHg (mean arterial pressure by 22 ± 5%), P < 0.0005. After the meal, blood pressure fell from 159 ± 8/88 ± 6 to 129 ± 6/70 ± 4 mmHg (mean arterial pressure by 22 ± 3%), P < 0.0001, and further during exercise to 123 ± 6/61 ± 3 mmHg (mean arterial pressure by 9 ± 3%), P < 0.01. The stroke distance—heart rate product, an index of cardiac output, did not change after the meal. During exercise, changes in the stroke distance—heart rate product were greater when fasted. 3. Resting forearm and calf vascular resistance were higher when fasted. Calf vascular resistance fell further after exercise when fasted. Resting superior mesenteric artery vascular resistance was lower when fed; 0.19 ± 0.02 compared with 032 ± 0.06, P < 0.05. After exercise, superior mesenteric artery vascular resistance had risen by 82%, to 0.53 ± 0.12, P < 0.05 (fasted) and by 47%, to 0.29 ± 0.05, P < 0.05 (fed). 4. On standing, absolute levels of blood pressure were higher when fasted [83 ± 7/52 ± 7 compared with 71 ± 2/41 ± 3 (fed), each P < 0.05]. Subjects were more symptomatic on standing post-exercise when fed. 5. In human sympathetic denervation, exercise in the fed state lowered blood pressure further than when fasted and worsened symptoms of postural hypotension.

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