scholarly journals Characterization and cardiovascular actions of endothelin-1 and endothelin-3 from the American alligator

2002 ◽  
Vol 282 (2) ◽  
pp. R594-R602 ◽  
Author(s):  
Björn Platzack ◽  
Yuqi Wang ◽  
Dane Crossley ◽  
Valentine Lance ◽  
James W. Hicks ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Resistance ◽  
Biological Activities ◽  
Systemic Blood Pressure ◽  
Second Phase ◽  
Systemic Blood ◽  
Cardiovascular Actions ◽  
Dose Dependent Decrease ◽  
Alligator Mississipiensis ◽  
Dose Dependent

The structures and biological activities of the isoforms of endothelin (ET) in a reptile are unknown. ET-3, whose primary structure is identical to human ET-3 except for the substitution Phe4 → Tyr, and a peptide identical to human ET-1 were isolated from an extract of the lung of the alligator, Alligator mississipiensis. Bolus intravenous injections of alligator ET-3 (10, 30, and 100 pmol/kg) into anesthetized alligators produced dose-dependent decreases in systemic blood pressure (Psys) and systemic vascular resistance (Rsys) without change in heart rate (HR), systemic blood flow (Qsys), pulmonary pressure (Ppul), pulmonary vascular resistance (Rpul), or pulmonary blood flow (Qpul). At a dose of 300 pmol/kg, the initial vasodilatation was followed by an increase in Rsys and decreases in Qsys and Ppul. The response to intravenous human/alligator ET-1 (10, 30, 100, and 300 pmol/kg) was biphasic at all doses with initial decreases in Psys and Rsys being followed by sustained increases in these parameters. In the pulmonary circulation, ET-1 produced a dose-dependent decrease in Qpul and an increase in Rpul during the first phase of the response but no significant change during the second phase. There was no change in HR in response to ET-1. The vasodilatator action of arginine, but not ET-1, was attenuated by N ω-nitro-l-arginine methyl ester, indicating that the effect of the peptide is probably not mediated through increased synthesis of nitric oxide. The data demonstrate that the structure of the ET isoforms has been strongly conserved during the evolution of vertebrates but that cardiovascular actions differ significantly between the alligator and mammals, especially in the magnitude and duration of the hypotensive response.

Protective role of NO in the regional hemodynamic changes during acute endotoxemia in rats

1994 ◽  
Vol 266 (4) ◽  
pp. H1558-H1564 ◽  
Author(s):  
M. F. Mulder ◽  
A. A. van Lambalgen ◽  
E. Huisman ◽  
J. J. Visser ◽  
G. C. van den Bos ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Resistance ◽  
Systemic Blood Pressure ◽  
Saline Group ◽  
Protective Role ◽  
Organ Blood Flow ◽  
Organ Perfusion ◽  
Hemodynamic Changes ◽  
Systemic Blood

The role of NO during the first hour of endotoxemia is still controversial. To evaluate whether NO is protective or detrimental to the regulation of systemic blood pressure, cardiac output (CO), and organ perfusion in rats during acute endotoxemia, we have studied the effects of inhibition of NO synthesis. Thirty minutes after 0.1 mg NG-nitro-L-arginine (L-NNA; group L, n = 7, partial inhibition), 1 mg L-NNA (group H, n = 6, complete inhibition), or saline (group E, n = 7) intravenous infusion, anesthetized volume-loaded rats were infused with endotoxin Escherichia coli O127:B8 (8 mg.kg-1 x h-1) from time (t) = 0 to 60 min. Organ blood flow was measured with radioactive microspheres. In group H, at time 0, CO was lower than in group E (by -29%; P < 0.05), and systemic vascular resistance (SVR) was higher than in groups E and L (by 72 and 51%, respectively; P < 0.05). Perfusion of the pancreas, stomach, intestines, and kidney was lower (P < 0.05) and corresponding organ vascular resistance (OVR) higher (P < 0.05) in group H than in groups E and L (except kidney in group L). At t = 60 min, in groups H and L, CO was lower (by -45 and -26%, respectively; P < 0.05) and SVR was higher (by 112 and 54%, respectively; P < 0.05) than in group E. In group L only blood flow to the heart, pancreas, intestines, and kidney was significantly lower than in group E, and corresponding OVR was higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal effect of meclofenamate in presence and absence of superfusion bioassay

1976 ◽  
Vol 230 (3) ◽  
pp. 711-714 ◽  
Author(s):  
S Satoh ◽  
BG Zimmerman
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Renal Artery ◽  
Renal Blood Flow ◽  
Vascular Resistance ◽  
Systemic Blood Pressure ◽  
Prostaglandin E ◽  
Renal Effect ◽  
Systemic Blood ◽  
Renal Vascular

Systemic blood pressure (SBP), renal blood flow (RBF), renal vascular resistance (RVR), and arterial and renal venous prostaglandin E (PGE) concentrations were determined in pentobarbital-anesthetized dogs.The effect of sodium meclofenamate infused into the renal artery was compared under two sets of conditions. In experiments carried out under control conditions, SBP, RBF, and RVR were stable and meclofenamate caused only a slight decrease in RBF (5.4%) and increase in RVR.

AN EXTRA-ADRENAL EFFECT OF CORTICOTROPHIN

1967 ◽  
Vol 37 (3) ◽  
pp. 245-252 ◽  
Author(s):  
E. STARK ◽  
B. VARGA ◽  
ZS. ÁCS
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Systemic Blood Pressure ◽  
Systemic Blood ◽  
Commercial Preparation ◽  
Naturally Occurring ◽  
Dose Dependent

SUMMARY Administered intravenously, a commercial preparation of naturally occurring corticotrophin as well as synthetic corticotrophin were found to raise ovarian blood flow both in the normal and in the adrenalectomized dog and cat, without affecting systemic blood pressure. Peaks and periods of time for which flow remained increased were dose-dependent.

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.

Control of Blood Pressure and the Distribution of Blood Flow

1991 ◽  
Vol 7 (S1) ◽  
pp. 79-84 ◽  
Author(s):  
Hans T. Versmold
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Peripheral Resistance ◽  
Systemic Blood Pressure ◽  
Adrenergic Innervation ◽  
Systemic Blood ◽  
Low Cardiac Output ◽  
Neurohumoral Control ◽  
The Brain

Systemic blood pressure (BP) is the product of cardiac output and total peripheral resistance. Cardiac output is controlled by the heart rate, myocardial contractility, preload, and afterload. Vascular resistance (vascular hindrance × viscosity) is under local autoregulation and general neurohumoral control through sympathetic adrenergic innervation and circulating catecholamines. Sympathetic innovation predominates in organs receivingflowin excess of their metabolic demands (skin, splanchnic organs, kidney), while innervation is poor and autoregulation predominates in the brain and heart. The distribution of blood flow depends on the relative resistances of the organ circulations. During stress (hypoxia, low cardiac output), a raise in adrenergic tone and in circulating catecholamines leads to preferential vasoconstriction in highly innervated organs, so that blood flow is directed to the brain and heart. Catecholamines also control the levels of the vasoconstrictors renin, angiotensin II, and vasopressin. These general principles also apply to the neonate.

scholarly journals Systemic and portal hemodynamic effects of anandamide

2001 ◽  
Vol 280 (1) ◽  
pp. G14-G20 ◽  
Author(s):  
Nelson Garcia ◽  
Zoltán Járai ◽  
Faridoddin Mirshahi ◽  
George Kunos ◽  
Arun J. Sanyal
Keyword(s):  
Vascular Resistance ◽  
Nordihydroguaiaretic Acid ◽  
Hemodynamic Effects ◽  
Venous Flow ◽  
Portal Hemodynamics ◽  
Sr 141716A ◽  
Dose Dependent Decrease ◽  
Endogenous Cannabinoid ◽  
Dose Dependent ◽  
Mesenteric Vascular Resistance

The endogenous cannabinoid anandamide causes hypotension and mesenteric arteriolar dilation. A detailed analysis of its effects on systemic and portal venous hemodynamics had not yet been performed. We assessed the effects of anandamide (0.4–10 mg/kg) on systemic and portal hemodynamics with and without prior treatment with various antagonists. The specific antagonists used included SR-141716A, N ω-nitro-l-arginine methyl ester, indomethacin, and nordihydroguaiaretic acid. Anandamide produced a dose-dependent decrease in mean arterial pressure due to a drop in systemic vascular resistance (SVR) that was accompanied by a compensatory rise in cardiac output. Anandamide also elicited an increase in both portal venous flow and pressure, along with a decline in mesenteric vascular resistance (MVR). Pretreatment with 3 mg/kg SR-141716A, a CB1 antagonist, prevented the decline of SVR and MVR from the lower dose of anandamide. Antagonism of nitric oxide synthetase, cyclooxygenase, or 5-lipoxygenase did not prevent the systemic nor the portal hemodynamic effects of anandamide. Furthermore, the use of R-methanandamide, a stable analog of anandamide, produced similar hemodynamic effects on the mesenteric vasculature, thereby implying that the effects of anandamide are not related to its breakdown products. Anandamide produced profound, dose-dependent alterations in both the systemic and portal circulations that could be at least partially blocked by pretreatment with SR-141716A.

scholarly journals Effects of Terpenes and Terpenoids of Natural Occurrence in Essential Oils on Vascular Smooth Muscle and on Systemic Blood Pressure: Pharmacological Studies and Perspective of Therapeutic Use

2020 ◽  
Author(s):  
Ana Carolina Cardoso-Teixeira ◽  
Klausen Oliveira-Abreu ◽  
Levy Gabriel de Freitas Brito ◽  
Andrelina Noronha Coelho-de-Souza ◽  
José Henrique Leal-Cardoso
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Biological Activities ◽  
Systemic Blood Pressure ◽  
Potential Effect ◽  
Natural Occurrence ◽  
Systemic Blood ◽  
Vascular Beds ◽  
Chemical Groups

Terpenes are a class of chemical compounds with carbon and hydrogen atoms in their structure. They can be classified into several classes according to the quantity of isoprene units present in its structure. Terpenes can have their structure modified by the addition of various chemical radicals. When these molecules are modified by the addition of atoms other than carbon and hydrogen, they become terpenoids. Terpenes and terpenoids come from the secondary metabolism of several plants. They can be found in the leaves, fruits, stem, flowers, and roots. The concentration of terpenes and terpenoids in these organs can vary according to several factors such as the season, collection method, and time of the day. Several biological activities and physiological actions are attributed to terpenes and terpenoids. Studies in the literature demonstrate that these molecules have antioxidant, anticarcinogenic, anti-inflammatory, antinociceptive, antispasmodic, and antidiabetogenic activities. Additionally, repellent and gastroprotective activity is reported. Among the most prominent activities of monoterpenes and monoterpenoids are those on the cardiovascular system. Reports on literature reveal the potential effect of monoterpenes and monoterpenoids on systemic blood pressure. Studies show that these substances have a hypotensive and bradycardic effect. In addition, the inotropic activity, both positive and negative, of these compounds has been reported. Studies also have shown that some monoterpenes and monoterpenoids also have a vasorelaxing activity on several vascular beds. These effects are attributed, in many cases to the blocking of ion channels, such as voltage-gated calcium channels. It can also be observed that monoterpenes and monoterpenoids can have their effects modulated by the action of the vascular endothelium. In addition, it has been shown that the molecular structure and the presence of chemical groups influence the potency and efficacy of these compounds on vascular beds. Here, the effect of several monoterpenes and monoterpenoids on systemic blood pressure and vascular smooth muscle will be reported.

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