Participation of central alpha-receptors on hemodynamic response to E. coli endotoxin

1984 ◽  
Vol 247 (4) ◽  
pp. R655-R662
Author(s):  
S. Koyama

The time course of changes in mean blood pressure (MBP), heart rate (HR), and renal blood flow (RBF) in a control group of anesthetized dogs given only endotoxin (1 mg/kg iv) was compared with groups pretreated with alpha-antagonists either intravenously or intracisternally (ic). The decreases in MBP and RBF in the control group were abolished by intracisternal prazosin (0.1 mg/kg ic). MBP response to endotoxin after intravenous prazosin did not differ from that of the control group; however, the endotoxin-induced decrease in RBF after intravenous prazosin was significantly greater than that in the control group. HR responses to endotoxin were not altered by either intracisternal or intravenous prazosin. MBP and RBF responses to endotoxin after intravenous or intracisternal yohimbine (0.5 mg/kg iv or ic) did not differ from the control responses. However, significant differences occurred in the time course of changes in HR only when yohimbine was administered intracisternally. These observations suggest that the hypotensive effect and reduction of RBF due to endotoxin may be mediated by alpha 1-adrenoceptors at least in the central nervous system and that of HR response may be mediated alpha 2-adrenoceptors.

1996 ◽  
Vol 85 (5) ◽  
pp. 1111-1119 ◽  
Author(s):  
Thomas N. Pajewski ◽  
Cosmo A. DiFazio ◽  
Jeffrey C. Moscicki ◽  
Roger A. Johns

Background Nitric oxide (NO), a recognized cell messenger for activating soluble guanylate cyclase, is produced by the enzyme NO synthase in a wide variety of tissues, including vascular endothelium and the central nervous system. The authors previously reported the possible involvement of the NO pathway in the anesthetic state by showing that a specific NO synthase inhibitor, nitroG-L-arginine methyl ester (L-NAME), dose dependently and reversibly decreases the minimum alveolar concentration (MAC) for halothane anesthesia. The availability of a structurally distinct inhibitor selective for the neuronal isoform of NO synthase, 7-nitro indazole (7-NI), allowed for the possibility of dissociating the central nervous system effects of neuronal NO synthase inhibition from the cardiovascular effects of endothelial NO synthase inhibition. Methods The effect of two structurally distinct inhibitors of NO synthase, L-NAME and 7-NI, on the MAC of isoflurane was investigated in Sprague-Dawley rats while concurrently monitoring the animals' arterial blood pressure and heart rate. L-NAME (1 to 30 mg/kg given intravenously, dissolved in 0.9% saline) and 7-NI (20 to 1,000 mg/kg given intraperitoneally, dissolved in arachis oil) were administered after determining control MAC and 30 min before determining MAC in the presence of NO synthase inhibitor. Results L-NAME and 7-NI caused a dose-dependent decrease from isoflurane control MAC (maximal effect: 35.5 +/- 2.5% and 43.0 +/- 1.7%, respectively) with a ceiling effect observed for both NO synthase inhibitors (above 10 mg/kg and 120 mg/kg, respectively). L-NAME administration significantly increased systolic and diastolic blood pressures (maximal effect: 39.9 +/- 2.2% and 64.3 +/- 4.0%, respectively), which were not accompanied by any changes in heart rate. 7-NI administration resulted in no changes in blood pressure and a small but clinically insignificant decrease in heart rate. Conclusions Inhibition of the NO synthase pathway decreased the MAC for isoflurane, which suggests that inhibition of the NO pathway decreases the level of consciousness and augments sedation, analgesia, and anesthesia. The MAC reduction by two structurally distinct NO synthase inhibitors supports that this is a specific effect on NO synthase. Furthermore, the action of the neuronal NO synthase inhibitor 7-NI supports an effect selective for neuronal NO synthase and also avoids the hypertensive response of generalized NO synthase inhibitors.


2018 ◽  
Vol 17 (3) ◽  
pp. 360-368
Author(s):  
Gulzhakhan Ryskalievna Zhakiyeva ◽  
Lyubov Muratovna Tulegenova ◽  
Nuria Zakarievna Ibragimova ◽  
Saubet Molbaevich Kelimberdiyev ◽  
Kulsin Kolganatovna Tokbayeva

Background: The objective is to study the time-dependent hemodynamic effects of altiazem PP-180 and the blood circulation parameters in patients with arterial hypertension of the II degree in outpatient polyclinic conditions.Methods: The study included 78 patients with essential II grade AH aged 42 to 73 years (mean age of 57.65 ± 0.6). Among them were 28 men and 50 women. The duration of the disease ranged from 4 to 23 years (an average of 9.2 ± 0.12). All the groups involved in the research were divided into two subgroups: the main group and the control group. The control group included 30 patients, who took A-180 once a day at non-fixed hours. The main group included 48 patients, who were divided into random subgroups depending on the time they took A-180 once a day. Within 3 days prior to treatment and during the 10-day treatment course, the medical staff measured all the pateints’ heart rate and blood pressure by NC Korotkoff every 3 hours, 6 times a day. The patients’ heart rate and blood pressure were alternatively self-measured. Prior to treatment and at the end of the 10-day course of therapy with altiazem PP-180, all the patients involved in the research underwent ECG examination and echocardiography on the Aloka machine (Japan).Results: The most favorable hemodynamic support for the hypotensive effect of altiazem PP-180 was observed when patients took it at 7 a.m., 10 a.m. and 10 p.m. in their normal mode of work and rest. When patients took altiazem PP-180 at 1 p.m, 4 p.m. and 7 p.m., its hypotensive effect was due to less favorable hemodynamic support.Conclusions: When taken at different hours of the day - both fixed and non-fixed hours - altiazem PP-180 caused a distinct hypotensive effect in patients with the II degree AH in outpatient polyclinic conditions.Bangladesh Journal of Medical Science Vol.17(3) 2018 p.360-368


Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.


2001 ◽  
Vol 6 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Harald Walach ◽  
Stefan Schmidt ◽  
Yvonne-Michelle Bihr ◽  
Susanne Wiesch

We studied the effect of experimenter expectations and different instructions in a balanced placebo design. 157 subjects were randomized into a 2 × 4 factorial design. Two experimenters were led to expect placebos either to produce physiological effects or not (pro- vs. antiplacebo). All subjects except a control group received a caffeine placebo. They were either made to expect coffee, no coffee, or were in a double-blind condition. Dependent measures were blood pressure, heart rate, well-being, and a cognitive task. There was one main effect on the instruction factor (p = 0.03) with the group “told no caffeine” reporting significantly better well-being. There was one main effect on the experimenter factor with subjects instructed by experimenter “proplacebo” having higher systolic blood pressure (p = 0.008). There was one interaction with subjects instructed by experimenter “proplacebo” to receive coffee doing worse in the cognitive task than the rest. Subjects instructed by experimenter “antiplacebo” were significantly less likely to believe the experimental instruction, and that mostly if they had been instructed to receive coffee. Contrary to the literature we could not show an effect of instruction, but there was an effect of experimenters. It is likely, however, that these experimenter effects were not due to experimental manipulations, but to the difference in personalities.


2019 ◽  
Vol 70 (5) ◽  
pp. 1754-1757
Author(s):  
Marius Toma Papacocea ◽  
Ioana Anca Badarau ◽  
Mugurel Radoi ◽  
Ioana Raluca Papacocea

Traumatic brain injuries (TBI) represent a high impact public health problem due to a high rate of death , long term disability and occurrence especially in young adults. Despite several promising animal studies, several parameters were proposed as biological markers and were assessed for this aim. Our study proposes the study of the early biochemical changes in association to hematological parameters for severe TBI patients prognosis. 43 patients with acute TBI were included in study based on clinical, laboratory and imagistic findings. The severity of the TBI was established by Glasgow Coma Scale GCS 3-8. In all patients were evaluated hematologic parameters (Red blood cell count - RBC, Hematocrit, blood Hemoglobin, White blood cell - WBC, Platelet count and biochemical parameters (glucose, urea, creatinine, electrolytes). Outcome was expressed as Glasgow Outcome Scale (GOS), between 1-5. Values were compared to control group -15 cases. Significant early differences in body temperature, heart rate, and systolic blood pressure were observed in TBI group versus control (p[0.05). After correlation, laboratory findings significantly associated to severe outcome - GOS = 1, 2 - (p[0.05) were plasma Na decrease and significant glucose increase. An early increase of temperature and decrease of Na may predict a severe outcome in patients with acute TBI; association with shifts in heart rate and blood pressure, imposes aggressive treatment measures.


2018 ◽  
Vol 25 (28) ◽  
pp. 3333-3352 ◽  
Author(s):  
Natalia Pessoa Rocha ◽  
Ana Cristina Simoes e Silva ◽  
Thiago Ruiz Rodrigues Prestes ◽  
Victor Feracin ◽  
Caroline Amaral Machado ◽  
...  

Background: The Renin-Angiotensin System (RAS) is a key regulator of cardiovascular and renal homeostasis, but also plays important roles in mediating physiological functions in the central nervous system (CNS). The effects of the RAS were classically described as mediated by angiotensin (Ang) II via angiotensin type 1 (AT1) receptors. However, another arm of the RAS formed by the angiotensin converting enzyme 2 (ACE2), Ang-(1-7) and the Mas receptor has been a matter of investigation due to its important physiological roles, usually counterbalancing the classical effects exerted by Ang II. Objective: We aim to provide an overview of effects elicited by the RAS, especially Ang-(1-7), in the brain. We also aim to discuss the therapeutic potential for neuropsychiatric disorders for the modulation of RAS. Method: We carried out an extensive literature search in PubMed central. Results: Within the brain, Ang-(1-7) contributes to the regulation of blood pressure by acting at regions that control cardiovascular functions. In contrast with Ang II, Ang-(1-7) improves baroreflex sensitivity and plays an inhibitory role in hypothalamic noradrenergic neurotransmission. Ang-(1-7) not only exerts effects related to blood pressure regulation, but also acts as a neuroprotective component of the RAS, for instance, by reducing cerebral infarct size, inflammation, oxidative stress and neuronal apoptosis. Conclusion: Pre-clinical evidence supports a relevant role for ACE2/Ang-(1-7)/Mas receptor axis in several neuropsychiatric conditions, including stress-related and mood disorders, cerebrovascular ischemic and hemorrhagic lesions and neurodegenerative diseases. However, very few data are available regarding the ACE2/Ang-(1-7)/Mas receptor axis in human CNS.


2018 ◽  
Vol 17 (2) ◽  
pp. 132-143 ◽  
Author(s):  
Mehmet Eray Alcigir ◽  
Halef Okan Dogan ◽  
Begum Yurdakok Dikmen ◽  
Kubra Dogan ◽  
Sevil Atalay Vural ◽  
...  

Background & Objective: Aroclor 1254 is a widespread toxic compound of Polychlorinated Biphenyls (PCBs), which can create significant nervous problems. No remedies have been found to date. The aim of this study was to reveal the damage that occurs in the central nervous system of rat pups exposed to Aroclor 1254 in the prenatal period and to show the inhibiting effect of curcumin, which is a strong anti-oxidant and neuroprotective substance. Method: The study established 3 groups of adult female and male Wistar albino rats. The rats were mated within these groups and the offspring rats were evaluated within the group given Aroclor 1254 only (n=10) and the group was given both Aroclor 1254 and curcumin (n=10) and the control group (n=10). The groups were compared in respect of pathomorphological damage. The immunohistochemical evaluation was made of 8-hydroxdeoxyguanosine (8-OHdG), 4-hydroxynoneal (4HNE), myelin basic protein (MBP) expressions and TUNEL reaction. The biochemical evaluation was made of the changes in the TAS-TOS and Neuron Specific Enolase (NSE) levels. Damage was seen to have been reduced with curcumin in the 8OHdG and TUNEL reactions, especially in the forebrain and the midbrain, although the dosage applied did not significantly change TAS and TOS levels. Consequently, it was understood that Aroclor 1254 caused damage in the central nervous system of the pup in the prenatal period, and curcumin reduced these negative effects, particularly in the forebrain and the midbrain. Conclusion: It was concluded that curcumin could be a potential neuroprotective agent and would be more effective at higher doses.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Menglu Jiang ◽  
Jiawei Ji ◽  
Xin Li ◽  
Zhenqing Liu

Abstract Background Endotracheal intubation and extubation may cause undesirable hemodynamic changes. Intravenous oxycodone has recently been introduced and used for relieving hemodynamic alterations in response to intubation, but there is insufficient information regarding its application in stabilizing hemodynamics during extubation in the patients emerging from general anesthesia. Methods One hundred patients, who had undergone assorted laparoscopic surgeries under general anesthesia, were randomly assigned to Control group (saline injection, 50 cases) and Study group (intravenous injection of 0.08 mg/kg oxycodone immediately after completion of the surgical procedure, 50 cases). Blood pressure, heart rate, blood oxygen saturation (SpO2) as well as blood concentrations of epinephrine, norepinephrine, and cortisol were recorded or measured immediately before extubation (T0), during extubation (T1), as well as one minute (T2), 5 min (T3), and 10 min after extubation (T4). In addition, coughing and restlessness, time of eye-opening, and duration from completing surgery to extubation as well as Ramsay Sedation Scale were analyzed. Results Blood pressure and heart rate as well as blood concentrations of epinephrine, norepinephrine, and cortisol were significantly higher in the Control group compared with the Study group at the time of extubation as well as 1, 5, and 10 min after extubation (P < 0.05). When the patients emerged from general anesthesia, 70 % of the Control group had cough, which was significantly higher than that of Study group (40 %, P < 0.05). Significantly higher number of patients manifested restlessness in the Control group before (40 %) and after extubation (20 %) compared with that in the Study group (20 and 2 %, respectively, P < 0.05). In addition, patients of Control group had lower Ramsay score at extubation (1.7 ± 0.7) as well as 30 min after extubation (2.4 ± 0.9) compared to that of the patients of Study group (2.2 ± 0.9, and 3.0 ± 0.8, respectively, P = 0.003 and 0.001). Conclusions Intravenous oxycodone attenuated alterations of hemodynamics and blood hormones associated with extubation during emergence from general anesthesia. Trial registration Chinese Clinical Trial Registry: ChiCTR2000040370 (registration date: 11-28-2020) “‘retrospectively registered”.


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