scholarly journals in vitro Effects of Calcium Antagonists PN 200-110, Nifedipine, and Nimodipine on Human and Canine Cerebral Arteries

1983 ◽  
Vol 3 (3) ◽  
pp. 354-361 ◽  
Author(s):  
E. Müller-Schweinitzer ◽  
P. Neumann
Keyword(s):  
Rank Order ◽  
Cerebral Arteries ◽  
Isometric Tension ◽  
Mesenteric Arteries ◽  
Organ Bath ◽  
Vasoconstrictor Response ◽  
Dihydropyridine Derivative ◽  
Basilar Arteries ◽  
In Vitro Effects

PN 200–110 [4-(2, 1, 3-benzoxadiazol - 4 -) - 1,4-dihydro - 2,6 - dimethyl - pyridine - 3,5 - dicarboxylic acid methyl 1-methylethyl ester], a new dihydropyridine derivative, was investigated by recording isometric tension on spiral strips from human and canine arteries in tissue baths at 37°C. Responses to increasing concentrations of CaCl2 were investigated in calcium-free depolarizing solution (60 mmol/L KCl in equimolar replacement for NaCl, 50 mmol/L TRIZMA buffer, pH 7.4). Comparison of those concentrations that reduced the vasoconstrictor response to 1.6 mmol/L CaCl2 by 50% revealed the following order of potencies on both human and canine arteries: PN 200–110 > nimodipine > nifedipine. Responses to 5-hydroxytryptamine (5-HT) and blood were investigated in Krebs–Henseleit solution (NaHCO3 buffer). On canine arteries, PN 200–110 antagonized responses to 5-HT when used at 10–30 pmol/L; it was ∼70 times more potent on basilar than on mesenteric arteries, whereas both nifedipine and nimodipine were, respectively, ∼10 and 6 times more potent on basilar than on mesenteric arteries. When canine basilar arteries were constricted by the addition of blood to the organ bath, each of the investigated dihydropyridine derivatives elicited concentration-dependent relaxation, producing the following order of potencies: PN 200–110 > nifedipine = nimodipine. On human anterior cerebral arteries, the blood-induced contractions were counteracted in the following rank order: PN 200–110 = nimodipine > nifedipine. The results suggest that due to its potent calcium-blocking activity on cerebral arteries, PN 200–110 might be of value for the prevention and treatment of cerebrovascular spasms following subarachnoid hemorrhage.

scholarly journals In Vitro Effects of Propofol on Gravid Human Myometrium

2008 ◽  
Vol 36 (6) ◽  
pp. 802-806 ◽  
Author(s):  
A. S. Thind ◽  
R. J. Turner
Keyword(s):  
Isometric Tension ◽  
Human Myometrium ◽  
Organ Bath ◽  
Dependent Manner ◽  
Uterine Contractility ◽  
Time Curve ◽  
Lower Segment Caesarean Section ◽  
Uterine Muscle ◽  
In Vitro Effects

The aim of this study was to evaluate the direct effect of propofol (di-isopropyl phenol) on the contractile properties of gravid human uterine muscle. Six specimens of uterine muscle were obtained from term parturients undergoing elective lower segment caesarean section. Small strips (1 × 2 x 12 mm) of muscle were prepared and suspended in an organ bath containing oxygenated Kreb's solution at 36.5°C. Following preparation, spontaneous regular contractions developed at a rate of one contraction every six to 10 minutes. Force of contraction was recorded continuously using an isometric tension transducer. Following baseline measurements, propofol was introduced into the bath at concentrations corresponding to 2 /μg/ml, 5 /μg/ml and 8 /μg/ml. The specimens were also exposed to intralipid in concentrations equivalent to that found in the 8 μ/ml solution of propofol to determine whether this additive influenced uterine contractility. Contractility (defined as area under the tension/time curve) was decreased to 89 ± 6.5% of control at 2 μg/ml 53±4.3% at 5 μ/ml and 45 ± 4.1% at 8 μg/ml. This decrease in contractility was statistically significant at concentrations >2 μg/ml. Intralipid did not significantly affect uterine contractility. The results of this study show that propofol decreases isolated human uterine muscle contractility in a dose-dependent manner.

Enhanced endothelin-1 response and receptor expression in small mesenteric arteries of insulin-resistant rats

2001 ◽  
Vol 280 (2) ◽  
pp. H522-H527 ◽  
Author(s):  
Prasad V. G. Katakam ◽  
Jennifer S. Pollock ◽  
David M. Pollock ◽  
Michael R. Ujhelyi ◽  
Allison W. Miller
Keyword(s):  
Receptor Expression ◽  
Mesenteric Arteries ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Binding Characteristics ◽  
Endothelin 1 ◽  
Insulin Resistant ◽  
Vasoconstrictor Response ◽  
Enhanced Expression

Hyperinsulinemia, a primary feature of insulin resistance, is associated with increased endothelin-1 (ET-1) activity. This study determined the vascular response to ET-1 and receptor binding characteristics in small mesenteric arteries of insulin-resistant (IR) rats. Rats were randomized to control (C) ( n = 32) or IR ( n = 32) groups. The response to ET-1 was assessed (in vitro) in arteries with (Endo+) and without (Endo−) endothelium. In addition, arteries (Endo+) were pretreated with the ETBantagonist A-192621 or the ETA antagonist A-127722. Finally, binding characteristics of [125I]ET-1 were determined. Results showed that in Endo+ arteries the maximal relaxation ( E max) to ET-1 was similar between C and IR groups; however, the concentration at 50% of maximum relaxation (EC50) was decreased in IR arteries. In Endo− arteries, the E max to ET-1 was enhanced in both groups. Pretreatment with A-192621 enhanced the E max and EC50 to ET-1 in both groups. In contrast, A-127722 inhibited the ET-1 response in all arteries in a concentration-dependent manner; however, a greater ET-1 response was seen at each concentration in IR arteries. Maximal binding of [125I]ET-1 was increased in IR versus C arteries although the dissociation constant values were similar. In conclusion, we found the vasoconstrictor response to ET-1 is enhanced in IR arteries due to an enhanced expression of ET receptors and underlying endothelial dysfunction.

Enhancement by vasopressin of adrenergic responses in human mesenteric arteries

1997 ◽  
Vol 272 (3) ◽  
pp. H1087-H1093 ◽  
Author(s):  
P. Medina ◽  
I. Noguera ◽  
M. Aldasoro ◽  
J. M. Vila ◽  
B. Flor ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Animal Experiments ◽  
Mesenteric Arteries ◽  
Organ Bath ◽  
Adrenergic Stimulation ◽  
Response Curves ◽  
Receptor Stimulation ◽  
Half Maximal Effective Concentration

Vasopressin not only acts directly on blood vessels through V1-receptor stimulation but also may modulate adrenergic-mediated responses in animal experiments in vitro and in vivo. The aim of the present study was to investigate whether subpressor concentrations of vasopressin could modify the constrictor responses to norepinephrine and electrical stimulation of the perivascular nerves in human mesenteric arteries. Human mesenteric artery rings (3-3.5 mm long, 0.8-1.2 mm OD) were obtained from 38 patients undergoing abdominal operations. The arterial rings were suspended in organ bath chambers for isometric recording of tension. Vasopressin (3 x 10(-11) M) enhanced the contractions elicited by electrical stimulation at 2, 4, and 8 Hz (by 100, 100, and 72%, respectively) and produced a leftward shift of the concentration-response curves to norepinephrine (half-maximal effective concentration decreased from 2.2 x 10(-6) to 5.0 x 10(-7) M; P < 0.05) without any alteration in maximal contractions. Vasopressin also potentiated KCl- and calcium-induced contractions. The V1-receptor antagonist 1-[beta-mercapto-beta,beta-cyclopentamethylenepropionic acid-2-O-methyl-tyrosine, 8-arginine]vasopressin (10(-6) M) prevented the potentiation evoked by vasopressin in all cases. The calcium antagonist nifedipine (10(-6) M) did not affect the potentiation of electrical stimulation and norepinephrine induced by vasopressin but abolished KCl-induced contractions. The results suggest that vasopressin, in addition to its direct vasoconstrictor effect, strongly potentiates the responses to adrenergic stimulation and KCl depolarization. Both the direct and indirect effects of vasopressin appear to be mediated by V1-receptor stimulation. The amplifying effect of vasopressin on constrictor responses may be relevant in those clinical situations characterized by increased plasma vasopressin levels.

Dose responses of cerebral arteries of the dog, rabbit, and man to human hemoglobin in vitro

1980 ◽  
Vol 53 (4) ◽  
pp. 486-490 ◽  
Author(s):  
Glyn R. Wellum ◽  
Thomas W. Irvine ◽  
Nicholas T. Zervas
Keyword(s):  
Cerebral Arteries ◽  
Postmortem Changes ◽  
Human Hemoglobin ◽  
Content Type ◽  
Weak Response ◽  
Basilar Arteries ◽  
Human Arteries ◽  
Dose Responses ◽  
Fine Print

✓ Dose responses in vitro of the basilar arteries of the dog, rabbit, and man to human hemoglobin are reported. For each species, the response occurred over a range of 10−9M to greater than 10−5M hemoglobin. When compared to a maximum serotonin contraction, the relative constriction induced by 10−5M hemoglobin was greater in the rabbit than in the dog, which in turn was greater than in man. The comparatively weak response of the human arteries is probably attributable to postmortem changes.

scholarly journals EP1- and EP3-Receptors Mediate Prostaglandin E2–Induced Constriction of Porcine Large Cerebral Arteries

2004 ◽  
Vol 24 (12) ◽  
pp. 1305-1316 ◽  
Author(s):  
Vikram Jadhav ◽  
Anthony Jabre ◽  
Shinn-Zong Lin ◽  
Tony Jer-Fu Lee
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Receptor Antagonist ◽  
Cerebral Arteries ◽  
Muscle Cells ◽  
Prostaglandin E ◽  
Receptor Subtypes ◽  
Basilar Arteries ◽  
Cerebral Vascular

Prostaglandin E2 (PGE2) has been shown to dilate and constrict the systemic vascular beds, including cerebral vessels. The exact mechanism of PGE2-induced cerebral vasoconstriction, however, is less clarified. The authors' preliminary studies showed that PGE2 exclusively constricted the adult porcine basilar arteries. The present study, therefore, was designed to examine the receptor mechanisms involved in PGE2-induced constriction of large cerebral arteries in the adult pig. Results from an in vitro tissue-bath study indicated that PGE2 and its agonists 17-phenyl trinor PGE2 (17-PGE2), sulprostone (EP1/EP3 receptor agonists), and 11-deoxy-16,16-dimethyl PGE2 (11-PGE2, an EP2/EP3-receptor agonist) induced exclusive constriction, which was not affected by endothelium denudation or cold-storage denervation of perivascular nerves. The constriction induced by PGE2, 17-PGE2, and sulprostone, but not by potassium chloride, was blocked by SC-19220 (a selective EP1-receptor antagonist), AH-6809 (an EP1/EP2-receptor antagonist), and U-73122 and neomycin (phospholipase C inhibitors). AH-6809, however, did not affect 11-PGE2–induced contraction. These results suggest that the contraction was not mediated by the EP2-receptor, but was mediated by EP1- and EP3-receptors. Furthermore, EP1-receptor immunoreactivities were found across the entire medial smooth muscle layers, whereas EP3-receptor immunoreactivities were limited to the outer smooth muscle layer toward the adventitia. Western blotting also showed the presence of EP1- and EP3-receptor proteins in cultured primary cerebral vascular smooth muscle cells. In conclusion, PGE2 exclusively constricts the adult porcine large cerebral arteries. This constriction is mediated by phosphatidyl–inositol pathway via activation of EP1- and EP3-receptors located on the smooth muscle cells. These two receptor subtypes may play important roles in physiologic and pathophysiologic control of cerebral vascular tone.

scholarly journals Endotoxin Decreases the Contractile Responses of the Porcine Basilar Artery to Vasoactive Substances

1993 ◽  
Vol 13 (4) ◽  
pp. 712-719 ◽  
Author(s):  
Masami Ueno ◽  
Tony J.-F. Lee
Keyword(s):  
Endothelial Cells ◽  
Basilar Artery ◽  
Muscle Tone ◽  
Cerebral Arteries ◽  
Contractile Responses ◽  
Vasoactive Substances ◽  
Basilar Arteries ◽  
Arterial Reactivity ◽  
Lps Treatment

The effects of endotoxin (lipopolysaccharide; LPS) on the reactivity of isolated porcine basilar artery were examined using in vitro tissue bath techniques. The active muscle tone of the basilar arterial rings with or without endothelial cells induced by U46619 (1 μ M) reached a plateau in 15 min, which was stable for the first hour and gradually decreased during the next 5 h. This time-dependent decrease in tone was significantly potentiated in the presence of LPS (20 μg/ml). The potentiation by LPS was blocked by Nw-nitro-l-arginine (l-NNA; 60 μ M), methylene blue (10 μ M), and dexamethasone (1 μ M) but not by hemoglobin (1 μ M). The effect of l-NNA was readily reversed by l-arginine but not by d-arginine. Furthermore, the contractile responses of porcine basilar arterial rings with or without intact endothelium to U46619 and KCl were decreased following incubation with LPS (20 μg/ml) for 4 h. Similar hyporeactivity was observed in cold storage–denervated cerebral arteries incubated with LPS for 4 h. This decrease in contractile responses in LPS-treated rings was reversed by 60 μ M l-NNA and 1 μ M dexamethasone. These results indicate that LPS treatment renders the porcine basilar arteries hyporesponsive to vasoconstrictors. Since effects of LPS were not modified by the presence of endothelial cells and perivascular neurons, the alteration in cerebral arterial reactivity may be due in part to an enhanced formation of nitric oxide from l-arginine in the vascular smooth muscle cells.

Cerebral vasospasm: contractile activity of hemoglobin in isolated canine basilar arteries

1980 ◽  
Vol 53 (6) ◽  
pp. 787-793 ◽  
Author(s):  
Takeo Tanishima
Keyword(s):  
Cerebral Vasospasm ◽  
Basilar Artery ◽  
Contractile Activity ◽  
Cerebral Arteries ◽  
Adenosine Monophosphate ◽  
Active Species ◽  
Exchange Chromatography ◽  
Basilar Arteries ◽  
Chronic Cerebral Vasospasm

✓ Recent studies suggest the possible role of the red blood cell (RBC) in causing chronic cerebral vasospasm. However, the basic action of hemoglobin (Hb), the major component of the RBC, on cerebral arteries remains unknown. The present study was undertaken to analyze the contractile effects of human Hb (purified by ion-exchange chromatography) on canine arteries in vitro. The contractile activity of lysed RBC was shown to be derived from Hb. Hemoglobin in oxygenated form (oxyHb) caused a maximum contraction equal to about 70% of that induced by serotonin in the basilar artery. Ferrous Hb's (oxyHb and carboxyHb) produced much greater contraction than ferric Hb's (methemoglobin and cyanmethemoglobin), suggesting that superoxide radicals, an active species of oxygen, may be related to the contractile activity of Hb. Neither methysergide, phentolamine, mepyramine, nor aspirin inhibited the vasoconstrictive activity of oxyHb. This finding indicates that the activation of serotonergic, alpha-adrenergic, or histaminergic H1 receptors, or prostaglandin synthesis may not be involved in the mechanism of action of oxyHb. The constituents of Hb caused little or no contraction as compared with Hb as a whole. The basilar artery was more highly sensitive to Hb than arteries from other anatomical locations. Cyclic adenosine monophosphate caused a very slight decrease in the Hb-induced contraction. It is concluded that oxyHb can contract cerebral arteries in vitro. These results, coupled with recent reports on the participation of the RBC in producing chronic vasospasm, strongly suggest that oxyHb released from RBC's plays an important role in the pathogenesis of chronic cerebral vasospasm.

scholarly journals In Vitro Effects of Magnesium Sulfate in Isolated Intrapulmonary and Mesenteric Arteries of Piglets

1996 ◽  
Vol 39 (6) ◽  
pp. 1107-1112 ◽  
Author(s):  
E Villamor ◽  
F Pérez-Vizcaíno ◽  
T Ruiz ◽  
J Tamargo ◽  
M Moro
Keyword(s):  
Magnesium Sulfate ◽  
Mesenteric Arteries ◽  
In Vitro Effects

scholarly journals Tyrosine Phosphorylation Modulates the Vascular Responses of Mesenteric Arteries from Human Colorectal Tumors

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Eduardo Ferrero ◽  
María Dolores Mauricio ◽  
Miriam Granado ◽  
Oscar García-Villar ◽  
Martín Aldasoro ◽  
...  
Keyword(s):  
Blood Flow ◽  
Tyrosine Phosphorylation ◽  
Isometric Tension ◽  
Mesenteric Arteries ◽  
Vegf Receptor ◽  
Organ Bath ◽  
Colorectal Tumors ◽  
Arterial Contraction ◽  
Normal Intestine ◽  
Stimulation Of

The aim of this study was to analyze whether tyrosine phosphorylation in tumoral arteries may modulate their vascular response. To do this, mesenteric arteries supplying blood flow to colorectal tumors or to normal intestine were obtained during surgery and prepared for isometric tension recording in an organ bath. Increasing tyrosine phosphorylation with the phosphatase inhibitor, sodium orthovanadate produced arterial contraction which was lower in tumoral than in control arteries, whereas it reduced the contraction to noradrenaline in tumoral but not in control arteries and reduced the relaxation to bradykinin in control but not in tumoral arteries. Protein expression of VEGF-A and of the VEGF receptor FLT1 was similar in control and tumoral arteries, but expression of the VEGF receptor KDR was increased in tumoral compared with control arteries. This suggests that tyrosine phosphorylation may produce inhibition of the contraction in tumoral mesenteric arteries, which may increase blood flow to the tumor when tyrosine phosphorylation is increased by stimulation of VEGF receptors.

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