Acute effect of 17 beta-estradiol on rabbit coronary artery contractile responses to endothelin-1

1992 ◽  
Vol 263 (1) ◽  
pp. H271-H275 ◽  
Author(s):  
C. Jiang ◽  
P. M. Sarrel ◽  
P. A. Poole-Wilson ◽  
P. Collins

We assessed the acute effect of 17 beta-estradiol on coronary artery constrictor responses to endothelin-1. 17 beta-Estradiol significantly shifted endothelin-1, calcium, or BAY K 8644 concentration-dependent contraction curves to the right in endothelium-denuded coronary arteries isolated from nonpregnant female rabbits. The -log 50% effective dose (ED50) of calcium in high KCl medium (100 mM) was 3.8 +/- 0.11 in control and 3.2 +/- 0.1 and 2.8 +/- 0.12 after incubation with 17 beta-estradiol (1 and 10 microM, respectively). The -log ED50 of BAY K 8644 (KCl 15 mM) was 7.8 +/- 0.1 in control and 7.4 +/- 0.08 and 7.2 +/- 0.05 in the presence of 17 beta-estradiol (1 and 10 microM, respectively). The -log ED50 of endothelin-1 was 9.2 +/- 0.08 in control and 8.8 +/- 0.1, 8.4 +/- 0.07, and 8.1 +/- 0.12 after incubation with 17 beta-estradiol (3, 10, and 30 microM, respectively). Similar results were obtained from coronary arteries of male rabbits. These increases of -log ED50 values were significant (P less than 0.05 or 0.01). 17 beta-Estradiol and verapamil induced dose-dependent relaxation in both endothelium-intact or -denuded coronary arteries submaximally precontracted by endothelin-1. NG-monomethyl-L-arginine had no effect on relaxation induced by 17 beta-estradiol, whereas it eliminated relaxation induced by acetylcholine in rings with an intact endothelium. These data suggest that 17 beta-estradiol attenuates the rabbit coronary artery contraction induced by endothelin-1 via an endothelium-independent mechanism, possibly by affecting calcium influx.

1990 ◽  
Vol 68 (5) ◽  
pp. 608-613 ◽  
Author(s):  
Mudumbi V. Ramagopal ◽  
S. Jamal Mustafa

Adenosine relaxes the coronary arteries of various species through A2 receptors. The aim of the present investigation was to evaluate the relaxing effects of adenosine in relation to the role of calcium in bovine coronary arteries by studying the vasodilatory effect of adenosine in normal and calcium-free medium and on calcium-45 efflux into calcium-free medium. Acetylcholine (ACh) and norepinephrine (NE) were used to induce tone in coronary artery rings. Adenosine, 5′-(N-ethylcarboxamido)adenosine (NECA), and N6-(L-phenylisopropyl)adenosine (L-PIA) produced concentration-dependent relaxations of the coronary artery rings. Both in normal and calcium-free medium, the order of potency for adenosine analogs (NECA > L-PIA > adenosine) was similar and 8-phenyltheophylline antagonized the relaxation responses to adenosine and its analogs. Removal of extracellular calcium shifted the concentration–response curves to the right in a parallel fashion, slowed the rate of relaxation, and in NE contracted rings reduced the maximum responses for adenosine and its analogs. In calcium-free medium, adenosine was without an effect on calcium-45 efflux in the presence of ACh. However, adenosine inhibited the stimulated calcium-45 efflux induced by NE. The data suggest that the vasodilatory action of adenosine in bovine coronary smooth muscle has both extracellular calcium-dependent and -independent components.Key words: adenosine receptors, calcium, coronary circulation, vascular smooth muscle, acetylcholine, norepinephrine.


2021 ◽  
Vol 27 (4) ◽  
pp. 41-46
Author(s):  
U.Ye. Pidvalna ◽  
D.M. Beshley ◽  
M.Z. Mirchuk ◽  
L.R. Mateshuk-Vatseba

Morphometric analysis of the structures of the aortic bulb and coronary arteries is necessary for the planning of cardiac surgery and endovascular interventions. The aim of the study was to determine the height of the coronary arteries branching in healthy women of Lviv city and Lviv region and to determine the relationship between the height of the location of the orifice of the coronary artery with anthropometric indicators. Fifteen computed tomography images with contrast of female thorax without heart and ascending aortic lesions (normal) were selected for the study. The height of the upper and lower edges of the coronary arteries was measured; height of Valsalva sinuses. The comparison of the mean values was performed according to the Student’s t-test. The correlation between the observed variables (age, height, body weight, body mass index, body surface area, height of the sinuses of Valsalva) was calculated using the Pearson linear correlation method (r). According to the study, the population group consisted of persons of the second period of adulthood (46.67 %) and the elderly (53.33 %). According to the body mass index, 80 % were overweight or obese I-II degree. The mean height of the coronary artery orifice in women without structural changes of the heart and ascending aorta was: 11.19±1.96 mm for the left and 11.68±1.80 mm for the right. The height of the orifice of the right and left coronary arteries were almost the same, without statistical significance (p=0.26). Analysis of the correlation between the values of the height of the orifice of the coronary artery did not show a probable dependence on height, weight, age, body mass index and body surface area. There is a direct relationship between the parameters of the height of the lower edge of the right coronary artery and the height of the upper edge of the right coronary artery (r=+0.75, p=0.001) and between the value of the lower edge of the left coronary artery and the upper edge of the left coronary artery (r=+0.63, p=0.01). Thus, the analysis of the correlation between the values of the height of the orifice of the coronary artery in women in norm and anthropometric indicators did not show a significant relationship. There was no statistical significance between the indicators of the height of the orifice of the right and left coronary arteries in women.


2021 ◽  
pp. 20-22
Author(s):  
Sony Jhansi Priya ◽  
Sangeetha A ◽  
M. Sai Krishna

Coronary artery variations are one of the commonest variations observed during clinical procedures. Normally, there are two main coronary arteries, the right coronary artery (RCA), left coronary artery (LCA).Left coronary artery gives two important branches left circumex artery (LCX) and left anterior descending (LAD) arteries. Knowledge about the coronary vessels and its variations are essential to clinicians to prevent untoward injury of vessels during any procedures. To study the morphology and variations of coronar Aim: y arteries by dissection. Materials and Methods: The present study was a cadaveric study which was conducted on 50 hearts obtained from adult human cadavers. Coronary arteries were dissected to see the origin, course and variations. The data was entered in Microsoft excel sheet and expressed in percentage. The Right Results: coronary artery branched out from the right aortic sinus and had an average diameter of 3.5mm. The left coronary artery arouse from left aortic sinus and had an average diameter of 4mm. LMCA divided into two branches in 60 percent, three branches in 30 percent and four branches in 06 percent of the hearts and direct branches from left aortic sinuus in 4 percent hearts.Based on the origin of Posterior descending or interventricular artery, Right dominance was observed in 68 percent, left dominance in 26 percent, and equal dominance in 06 percent of the hearts. Conclusion: Knowledge about the variations of coronary vessels is a prerequisite for clinicians to perform interventions of coronary vessels.


Author(s):  
Xhevdet Krasniqi ◽  
Hajdin Çitaku

Coronary arteries supply the heart muscle with blood maintaining myocardial hemostasis and function. Coronary artery anomalies may persist after birth affecting cardiovascular system through haemodynamic impairment caused from shunting, ischaemia, especially in young children or adolescents and young adults. In patients undergoing coronary angiography the incidence of anomalous origination of the left coronary artery from right sinus is 0.15% and the right coronary artery from the left sinus is 0.92%. A recent classification of the coronary anomalies is based on anatomical considerations, recognizing three categories: anomalies of the origin and course, anomalies of the intrinsic coronary artery anatomy, and anomalies of the termination. In the setting of anomalous coronary artery from the opposite sinus, the proximal anomalous CA may run anterior to the pulmonary trunk (prepulmonic), posterior to the aorta (retroaortic), septal (subpulmonic), or between the pulmonary artery and the aorta itself (interarterial). Among them, only those with an interarterial aorta-pulmonary course are regarded as hidden conditions at risk of ischaemia and even sudden death. We presented two cases with anomalous origin of coronary arteries from opposite sinus, and two other cases with anomalous origin of left circumflex artery. The atherosclerotic coronary artery disease leads to the need of coronarography which can find out the presence of coronary artery anomalies. Anomalous origin of coronary artery that is present with atherosclerotic changes continues to exist as a challenge during treatment in interventional cardiology.


2000 ◽  
Vol 10 (3) ◽  
pp. 281-285 ◽  
Author(s):  
John C. Wood ◽  
Miguel Reyes-Mugica ◽  
Gary Kopf

AbstractWe describe a patient with pulmonary atresia and intact ventricular septum in whom the right atrium was divided by a vascular aneurysm located in the right atrioventricular groove. We postulate that the structure represents an aneursymally dilated right coronary artery taking anomalous origin from the pulmonary trunk, with fistulous communication to the right atrium. We discuss the findings relative to concepts of development of the coronary arteries in normal hearts and in pulmonary atresia with an intact ventricular septum.


2014 ◽  
Vol 03 (03) ◽  
pp. 143-149
Author(s):  
Apsara M P.

Abstract Background and aims: The incidence of Coronary Artery Disease (CAD) has reached alanning proportions in India. The pathological hall mark of CAD is myocardial ischemia resulting from the atherosclerotic narrowing of coronary arteries. In this era of advanced interventions and cardiac surgery, a thorough knowledge of normal and variant anatomy of coronary arteries is of prime significance and of great use both to the clinicians and anatomists. Materials and methods: One hundred coronary angiograms of patients free of disease were studied in detail in different profiles. The data obtained was quantified according to their frequencies. The relation between the length of left main coronary artery and coronary artery dominance was statistically analyzed using the 'Chi Square test for Trend'. Results: This study highlighted some interesting findings such as the origin of Sino- atrial nodal artery from the second segment of right coronary artery in 3% of cases, double right marginal artery in 4% cases. Other variations such as Mouchet's posterior recurrent interventricular artery, origin of circumflex artery from the right coronary artery and abnormal communication between the terminal parts of right coronary artery and circumflex artery were each noticed in 1 % of cases. Conclusions: Coronary arteries and their branches are prone to variations in their course and morphology. Prior knowledge about this is important for the interpretation of coronary angiograms and surgical myocardial revascularization. The present work on normal and variant pattern of coronary arteries will help in gathering momentum to the already advancing research work in this field.


1994 ◽  
Vol 266 (4) ◽  
pp. H1322-H1326 ◽  
Author(s):  
M. A. Conway ◽  
M. T. Nelson ◽  
J. E. Brayden

The mechanisms responsible for coronary vasodilation during ischemia or hypoxia are poorly understood. It has recently been suggested that alterations in intracellular ATP may play a role in this response. We examined whether dilation of isolated coronary arteries in response to metabolic blockade by 2-deoxyglucose, which competitively inhibits glycolysis and glycogenolysis, was sensitive to glibenclamide, an inhibitor of ATP-sensitive potassium channels. Pressurized rat coronary arteries with myogenic tone dilated in response to 2-deoxyglucose by an endothelium-independent mechanism. The dilation was accompanied by a substantial hyperpolarization. Addition of glibenclamide partially reversed this vasodilation and abolished the hyperpolarization. We propose that ATP-sensitive potassium channels play a significant role in the dilator response to 2-deoxyglucose. This may have implications both for ischemia-induced coronary vasodilation and for the use of oral hypoglycemic agents in general.


2009 ◽  
Vol 297 (5) ◽  
pp. H1949-H1955 ◽  
Author(s):  
Thomas Wischgoll ◽  
Jenny S. Choy ◽  
Ghassan S. Kassab

The morphometry (diameters, length, and angles) of coronary arteries is related to their function. A simple, easy, and accurate image-based method to seamlessly extract the morphometry for coronary arteries is of significant value for understanding the structure-function relation. Here, the morphometry of large (≥1 mm in diameter) coronary arteries was extracted from computed tomography (CT) images using a recently validated segmentation algorithm. The coronary arteries of seven pigs were filled with Microfil, and the cast hearts were imaged with CT. The centerlines of the extracted vessels, the vessel radii, and the vessel lengths were identified for over 700 vessel segments. The extraction algorithm was based on a topological analysis of a vector field generated by normal vectors of the extracted vessel wall. The diameters, lengths, and angles of the right coronary artery, left anterior descending coronary artery, and left circumflex artery of all vessels ≥1 mm in diameter were tabulated for the respective orders. It was found that bifurcations at orders 9–11 are planar (∼90%). The relations between volume and length and area and length were also examined and found to scale as power laws. Furthermore, the bifurcation angles follow the minimum energy hypothesis but with significant scatter. Some of the applications of the semiautomated extraction of morphometric data in applications to coronary physiology and pathophysiology are highlighted.


2009 ◽  
Vol 19 (6) ◽  
pp. 627-629 ◽  
Author(s):  
Haci Ciftci ◽  
Gulten Tacoy ◽  
Guliz Yazici

AbstractHypertrophic cardiomyopathy is a genetic myocardial disorder. In such patients, myocardial bridging is the most frequent encountered coronary arterial anomaly. Patients may, however, on occasion, present with other much rarer malformations of the coronary arteries. Duplication of the right coronary artery is a very rare anomaly. We have now encountered a patient with hypertrophic cardiomyopathy in whom we found myocardial bridging of the anterior interventricular coronary artery and duplication of the right coronary artery. To the best of our knowledge, this association has not previously been described.


1981 ◽  
Vol 103 (3) ◽  
pp. 208-212 ◽  
Author(s):  
B. Fox ◽  
W. A. Seed

We have correlated the location of early atheroma with vessel geometry in the major coronary arteries of subjects dying of noncardiovascular causes under 40 yr of age. We analyzed only those vessels affected minimally by very early (fatty) disease. In each of the three major branches, disease was concentrated close to the entrance and diminished with distance downstream. Circumferential distribution of disease was also not random. In the right coronary artery, lesions were concentrated on the inner wall of the major curvature. Immediately downstream of the entrances of both branches of the left coronary artery, the flow-dividing walls were spared. Further downstream in the left anterior, descending branch plaques followed a spiral distribution. We believe these patterns may be determined by local mechanical factors.


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