scholarly journals Cerebrovascular effects of endothelin-1 investigated using high-resolution magnetic resonance imaging in healthy volunteers

2019 ◽  
Vol 40 (8) ◽  
pp. 1685-1694 ◽  
Author(s):  
Anders Hougaard ◽  
Samaira Younis ◽  
Afrim Iljazi ◽  
Kristian A Haanes ◽  
Ulrich Lindberg ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Healthy Volunteers ◽  
Cerebrovascular Disorders ◽  
High Dose ◽  
Double Blind ◽  
Endothelin 1 ◽  
Arterial Blood ◽  
Potent Vasoconstrictor ◽  
Double Blind Design

Endothelin-1 (ET-1) is a highly potent vasoconstrictor peptide released from vascular endothelium. ET-1 plays a major role in cerebrovascular disorders and likely worsens the outcome of acute ischaemic stroke and aneurismal subarachnoid haemorrhage through vasoconstriction and cerebral blood flow (CBF) reduction. Disorders that increase the risk of stroke, including hypertension, diabetes mellitus, and acute myocardial infarction, are associated with increased plasma levels of ET-1. The in vivo human cerebrovascular effects of systemic ET-1 infusion have not previously been investigated. In a two-way crossover, randomized, double-blind design, we used advanced 3 tesla MRI methods to investigate the effects of high-dose intravenous ET-1 on intra- and extracranial artery circumferences, global and regional CBF, and cerebral metabolic rate of oxygen (CMRO2) in 14 healthy volunteers. Following ET-1 infusion, we observed a 14% increase of mean arterial blood pressure, a 5% decrease of middle cerebral artery (MCA) circumference, but no effects on extracerebral arteries and no effects on CBF or CMRO2. Collectively, the findings indicate MCA constriction secondarily to blood pressure increase and not due to a direct vasoconstrictor effect of ET-1. We suggest that, as opposed to ET-1 in the subarachnoid space, intravascular ET-1 does not exert direct cerebrovascular effects in humans.

Antihypertensive effect of mechanism-based inhibition of renal arachidonic acid ω-hydroxylase activity

2002 ◽  
Vol 283 (3) ◽  
pp. R710-R720 ◽  
Author(s):  
Fengyun Xu ◽  
Wesley O. Straub ◽  
Winnie Pak ◽  
Ping Su ◽  
Kristopher G. Maier ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rat ◽  
Spontaneously Hypertensive ◽  
Arterial Blood ◽  
Vasoconstrictor Response ◽  
Potent Vasoconstrictor ◽  
Acetylenic Fatty Acid ◽  
Regulation Of Blood Pressure

The cytochrome P-450 eicosanoid 20-hydroxyeicosatetraenoic acid (20-HETE) is a potent vasoconstrictor that is implicated in the regulation of blood pressure. The identification of selective inhibitors of renal 20-HETE formation for use in vivo would facilitate studies to determine the systemic effects of this eicosanoid. We characterized the acetylenic fatty acid sodium 10-undecynyl sulfate (10-SUYS) as a potent and selective mechanism-based inhibitor of renal 20-HETE formation. A single dose of 10-SUYS caused an acute reduction in mean arterial blood pressure in 8-wk-old spontaneously hypertensive rats. The decrease in mean arterial pressure was maximal 6 h after 10-SUYS treatment (17.9 ± 3.2 mmHg; P < 0.05), and blood pressure returned to baseline levels within 24 h after treatment. Treatment with 10-SUYS was associated with a decrease in urinary 20-HETE formation in vivo and attenuation of the vasoconstrictor response of renal interlobar arteries to ANG II in vitro. These results provide further evidence that 20-HETE plays an important role in the regulation of blood pressure in the spontaneously hypertensive rat.

Effect of High-Dose Ibuprofen on 24-Hour Blood Pressure in Healthy Women

1987 ◽  
Vol 21 (6) ◽  
pp. 517-521 ◽  
Author(s):  
James M. Mckenney ◽  
Jackson T. Wright ◽  
Robert P. Goodman ◽  
Laverne Cooper ◽  
Nancy Yunker ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Monitoring ◽  
Prostaglandin E ◽  
High Dose ◽  
Pressure Monitoring ◽  
Percent Reduction ◽  
Double Blind ◽  
Salt Diet ◽  
Double Blind Design ◽  
Added Salt

The nonsteroidal anti-inflammatory drug (NSAID) indomethacin has been shown to increase blood pressure in normotensive individuals. The effect of other NSAID on blood pressure has not been as well studied. We evaluated the effects of ibuprofen, an NSAID currently available without a prescription, on 24-hour ambulatory blood pressure in ten young, healthy, normotensive women. Using a randomized, crossover, double-blind design, subjects received ibuprofen 800 mg and a placebo identical in appearance to ibuprofen three times a day for eight days with a washout period between regimens. Subjects were instructed to follow a no-added salt diet during the study. Twenty-four-hour blood pressure monitoring and 24-hour urine collection for prostaglandin E2, creatinine, and sodium were performed on days 1 and 8 of each study week. Tablet counts and a 40 percent reduction in urinary prostaglandin E2 documented compliance with ibuprofen. Ibuprofen had no significant effect on systolic or diastolic blood pressure at any hour during the 24-hour period. Mean blood pressure for the 24-hour period was 112/73 and 111/73 mm Hg on day 1 and 111/73 and 112/73 mm Hg on day 8 for placebo and ibuprofen, respectively. We conclude that ibuprofen at doses as high as 2400 mg/d for up to seven days has no effect on blood pressure in normotensive women. Further studies are needed in hypertensive subjects.

Cardiovascular Effects of Micromeria graeca (L.) Benth. ex Rchb in Normotensive and Hypertensive Rats

2020 ◽  
Vol 20 (8) ◽  
pp. 1253-1261
Author(s):  
Mourad Akdad ◽  
Mohamed Eddouks
Keyword(s):  
Blood Pressure ◽  
Cardiovascular System ◽  
Arterial Blood Pressure ◽  
Antihypertensive Activity ◽  
Computer Assisted ◽  
Hypertensive Rats ◽  
Vasorelaxant Effect ◽  
Arterial Blood

Aims: The present study was performed in order to analyze the antihypertensive activity of Micromeria graeca (L.) Benth. ex Rchb. Background: Micromeria graeca (L.) Benth. ex Rchb is an aromatic and medicinal plant belonging to the Lamiaceae family. This herb is used to treat various pathologies such as cardiovascular disorders. Meanwhile, its pharmacological effects on the cardiovascular system have not been studied. Objective: The present study aimed to evaluate the effect of aqueous extract of aerial parts of Micromeria graeca (AEMG) on the cardiovascular system in normotensive and hypertensive rats. Methods: In this study, the cardiovascular effect of AEMG was evaluated using in vivo and in vitro investigations. In order to assess the acute effect of AEMG on the cardiovascular system, anesthetized L-NAME-hypertensive and normotensive rats received AEMG (100 mg/kg) orally and arterial blood pressure parameters were monitored during six hours. In the sub-chronic study, rats were orally treated for one week, followed by blood pressure assessment during one week of treatment. Blood pressure was measured using a tail-cuff and a computer-assisted monitoring device. In the second experiment, isolated rat aortic ring pre-contracted with Epinephrine (EP) or KCl was used to assess the vasorelaxant effect of AEMG. Results: Oral administration of AEMG (100 mg/kg) provoked a decrease of arterial blood pressure parameters in hypertensive rats. In addition, AEMG induced a vasorelaxant effect in thoracic aortic rings pre-contracted with EP (10 μM) or KCl (80 mM). This effect was attenuated in the presence of propranolol and methylene blue. While in the presence of glibenclamide, L-NAME, nifedipine or Indomethacin, the vasorelaxant effect was not affected. Conclusion: This study showed that Micromeria graeca possesses a potent antihypertensive effect and relaxes the vascular smooth muscle through β-adrenergic and cGMP pathways.

Vasorelaxant and Antihypertensive Effects of Mentha pulegium L. in Rats: An in vitro and in vivo Approach

2020 ◽  
Vol 20 ◽  
Author(s):  
Mohammed Ajebli ◽  
Mohamed Eddouks
Keyword(s):  
Blood Pressure ◽  
Acute Experiment ◽  
Antihypertensive Activity ◽  
Mentha Pulegium ◽  
In Vitro Experiment ◽  
Arterial Blood ◽  
Dose Dependent ◽  
Ca2 Channels

Aims and objective: The aim of the study was to investigate the effect of aqueous aerial part extract of Mentha pulegium L. (Pennyrile) (MPAE) on arterial pressure parameters in rats. Background: Mentha pulegium is a medicinal plant used to treat hypertension in Morocco. Material and methods: In the current study, MPAE was prepared and its antihypertensive activity was pharmacologically investigated. L-NAME-hypertensive and normotensive rats have received orally MPAE (180 and 300 mg/kg) during six hours for the acute experiment and during seven days for the sub-chronic treatment. Thereafter, systolic, diastolic, mean arterial blood pressure and heart rate were evaluated. While, in the in vitro experiment, isolated denuded and intact thoracic aortic rings were suspended in a tissue bath system and the tension changes were recorded. Results: A fall in blood pressure was observed in L-NAME-induced hypertensive treated with MPAE. The extract also produced a dose-dependent relaxation of aorta pre-contracted with NE and KCl. The study showed that the vasorelaxant ability of MPAE seems to be exerted through the blockage of extracellular Ca2+ entry. Conclusion: The results demonstrate that the extract of pennyrile exhibits antihypertensive activity. In addition, the effect may be, at least in part, due to dilation of blood vessels via blockage of Ca2+ channels.

Methylprednisolone on circulating eicosanoids and vasomotor tone after endotoxin

1986 ◽  
Vol 61 (1) ◽  
pp. 185-191 ◽  
Author(s):  
C. A. Hales ◽  
R. D. Brandstetter ◽  
C. F. Neely ◽  
M. B. Peterson ◽  
D. Kong ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Vascular Resistance ◽  
Systemic Blood Pressure ◽  
Physiological Effect ◽  
High Dose ◽  
Systemic Blood ◽  
Eicosanoid Production ◽  
Circulating Levels

Acute pulmonary and systemic vasomotor changes induced by endotoxin in dogs have been related, at least in part, to the production of eicosanoids such as the vasoconstrictor thromboxane and the vasodilator prostacyclin. Steroids in high doses, in vitro, inhibit activation of phospholipase A2 and prevent fatty acid release from cell membranes to enter the arachidonic acid cascade. We, therefore, administered methylprednisolone (40 mg/kg) to dogs to see if eicosanoid production and the ensuing vasomotor changes could be prevented after administration of 150 micrograms/kg of endotoxin. The stable metabolites of thromboxane B2 (TxB2) and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) were measured by radioimmunoassay. Methylprednisolone by itself did not alter circulating eicosanoids but when given 2.5 h before endotoxin not only failed to inhibit endotoxin-induced eicosanoid production but actually resulted in higher circulating levels of 6-keto-PGF1 alpha (P less than 0.05) compared with animals receiving endotoxin alone. Indomethacin prevented the steroid-enhanced concentrations of 6-keto-PGF1 alpha after endotoxin and prevented the greater fall (P less than 0.05) in systemic blood pressure and systemic vascular resistance with steroid plus endotoxin than occurred with endotoxin alone. Administration of methylprednisolone immediately before endotoxin resulted in enhanced levels (P less than 0.05) of both TxB2 and 6-keto-PGF1 alpha but with a fall in systemic blood pressure and vascular resistance similar to the animals pretreated by 2.5 h. In contrast to the early steroid group in which all of the hypotensive effect was due to eicosanoids, in the latter group steroids had an additional nonspecific effect. Thus, in vivo, high-dose steroids did not prevent endotoxin-induced increases in eicosanoids but actually increased circulating levels of TxB2 and 6-keto-PGF1 alpha with a physiological effect favoring vasodilation.

Compression Stocking Length Effects on Arterial Blood Pressure and Heart Rate Following Head-Up Tilt in Healthy Volunteers

2014 ◽  
Vol 63 (6) ◽  
pp. 435-438 ◽  
Author(s):  
Kunihiko Tanaka ◽  
Shiori Tokumiya ◽  
Yumiko Ishihara ◽  
Yumiko Kohira ◽  
Tetsuro Katafuchi
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Healthy Volunteers ◽  
Arterial Blood Pressure ◽  
Compression Stocking ◽  
Arterial Blood ◽  
Head Up Tilt ◽  
Length Effects

Dilutional Acidosis following Hetastarch or Albumin in Healthy Volunteers

2000 ◽  
Vol 93 (5) ◽  
pp. 1184-1187 ◽  
Author(s):  
Jonathan H. Waters ◽  
Clifford A. Bernstein
Keyword(s):  
Healthy Volunteers ◽  
Repeated Measures ◽  
Base Excess ◽  
Rank Test ◽  
Albumin Concentration ◽  
Acid Base Balance ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
The Impact

Background The intent of this study was to evaluate the impact of the commonly used colloids-hetastarch and albumin-on in vivo acid-base balance. From this evaluation, a better understanding of the mechanism of dilutional acidosis was expected. Methods In a prospective, randomized fashion, 11 healthy volunteers were administered 15 ml/kg hetastarch solution, 6%, or 15 ml/kg albumin, 5%, intravenously over 30 min. Four weeks later, the study subjects were administered the other colloid. Arterial blood gas and electrolyte parameters were measured at baseline and at 30, 60, 90, 120, 210, and 300 min after colloid administration. Pre- and postlaboratory values were compared within groups using a paired t test and a Wilcoxon signed rank test and between groups using repeated-measures analysis of variance and a Wilcoxon rank sum test. Results Thirty min after infusion, subjects who were administered hetastarch showed statistically significant changes (P &lt; 0.05) in base excess (from 2.5 +/- 0.9 mEq/l to 0.7 +/- 1.1 mEq/l), HCO3- concentration (from 27 +/- 1.0 mEq/l to 25 +/- 1.3 mEq/l), Cl- concentration (from 108 +/- 2 mEq/l to 112 +/- 2 mEq/l), albumin concentration (from 4.4 +/- 0.2 g/dl to 3.5 +/- 0.5 g/dl), and arterial carbon dioxide tension (Paco2; from 40.8 +/- 2.3 mmHg to 39. 2 +/- 3.2 mmHg), whereas only the albumin concentration (from 4.4 +/- 0.2 g/dl to 4.8 +/- 0.6 g/dl) changed significantly in the albumin-treated group. Conclusions Decreases in base excess were observed for 210 min after hetastarch administration but not after albumin. The mechanism for this difference is discussed.

Solumedrol Treatment for Severe Sepsis in Humans with a Blunted Adrenocorticotropic Hormone-Cortisol Response: A Prospective Randomized Double-Blind Placebo-Controlled Pilot Clinical Trial

2021 ◽  
pp. 088506662110388
Author(s):  
Divya Birudaraju ◽  
Sajad Hamal ◽  
John A. Tayek
Keyword(s):  
Blood Pressure ◽  
Clinical Trial ◽  
Adrenocorticotropic Hormone ◽  
Serum Cortisol ◽  
High Dose ◽  
Cortisol Response ◽  
Acth Stimulation ◽  
Double Blind ◽  
Significant Difference ◽  
To Receive

Purpose To test the benefits of Solumedrol treatment in sepsis patients with a blunted adrenocorticotropic hormone (ACTH)-cortisol response (delta <13 µg/dL) with regard to the number of days on ventilator, days on intravenous blood pressure support, length of time in an intensive care unit (ICU), 14-day mortality, and 28-day mortality. The trial was prospective, randomized, and double-blind. As part of a larger sepsis trial, 54 patients with sepsis had an intravenous ACTH stimulation test using 250 µg of ACTH, and serum cortisol was measured at times 0, 30, and 60 min. Eleven patients failed to increase their cortisol concentration above 19.9 µg/dL and were excluded from the clinical trial as they were considered to have adrenal insufficiency. The remaining 43 patients had a baseline cortisol of 32 ± 1 µg/dL increased to 38 ± 3 µg/dL at 30 min and 40 ± 3 at 60 min. All cortisol responses were <12.9 µg/dL between time 0 and time 60, which is defined as a blunted cortisol response to intravenous ACTH administration. Twenty-one were randomized to receive 20 mg of intravenous Solumedrol and 22 were randomized to receive a matching placebo every 8 h for 7-days. There was no significant difference between the two randomized groups. Data analysis was carried out bya two-tailed test and P < .05 as significant. Results Results: The mean age was 51 ± 2 (mean ± SEM) with 61% female. Groups were well matched with regard to APACHE III score in Solumedrol versus placebo (59 ± 6 vs 59 ± 6), white blood cell count (18.8 ± 2.2 vs 18.6 ± 2.6), and incidence of bacteremia (29 vs 39%). The 28-day mortality rate was reduced in the Solumedrol treated arm (43 ± 11 vs 73 ± 10%; P < .05). There was no change in days in ICU, days on blood pressure agents, or days on ventilator. Seven days of high-dose intravenous Solumedrol treatment (20 mg every 8 h) in patients with a blunted cortisol response to ACTH was associated with an improved 28-day survival. This small study suggests that an inability to increase endogenous cortisol production in patients with sepsis who are then provided steroid treatment could improve survival.

A randomised pilot trial of the anti-von Willebrand factor aptamer ARC1779 in patients with type 2b von Willebrand disease

2010 ◽  
Vol 104 (09) ◽  
pp. 563-570 ◽  
Author(s):  
Petra Paulinska ◽  
Petra Jilma-Stohlawetz ◽  
James Gilbert ◽  
Renta Hutabarat ◽  
Paul Knöbl ◽  
...  
Keyword(s):  
Pilot Trial ◽  
Coagulation Factor ◽  
Von Willebrand Disease ◽  
Double Blind ◽  
Clinical Trial Registration ◽  
Maximal Increase ◽  
Double Blind Design ◽  
Von Willebrand

SummaryDesmopressin aggravates thrombocytopenia in type 2B von Willebrand disease (VWF type 2B) by release of large and hyper-adhesive von Wille-brand Factor (VWF) multimers. This pilot study investigated whether the anti-VWF aptamer ARC1779 can prevent desmopressin-induced thrombocytopenia and interferes with the excessive VWF turnover in patients with VWF type 2B. Concentration effect curves of ARC1779 were established for five patients in vitro and two patients with VWF type 2B were treated by infusion of ARC1779, desmopressin, or their combination in a randomised, controlled, double-blind design. ARC1779 concentrations in the range of 1–3 μg/ml blocked free A1 domain binding sites by 90% in vitro. In vivo, desmopressin alone induced a profound (-90%) drop in platelet counts in one of the patients. ARC1779 (4–5 μg/ml) completely inhibited VWF A1 domains and prevented this desmopress-in-induced platelet drop. Desmopressin alone increased VWF antigen two- to three-fold, accompanied by concordant changes in VWF Ristocetin cofactor activity (RCo) and coagulation factor VIII activity. ARC1779 substantially enhanced the desmopressin-induced maximal increase in these parameters, and improved multimer patterns. No treatment related adverse events were observed and no bleeding occurred despite marked thrombocytopenia. These data provide first proof of concept in humans and evidence that ARC1779 is a potent inhibitor of VWF. ARC1779 prevented the rapid consumption of VWF multimers together with agglutinated platelets that occurred in response to desmopressin challenge in patients with VWD type 2B.Clinical Trial registration number: NCT00632242.

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