Different accumulation of elements in the rami of the coronary arteries of Thai

To analyze the accumulation of elements in the rami of the coronary arteries, the authors determined element contents in both the coronary arteries and their rami of the Thai by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 13 men and 6 women, ranging in age from 34 to 83 yr. It was found that a higher accumulation of calcium and phosphorus occurred in the proximal sites of coronary arteries such as the anterior descending, right coronary, left coronary, and circumflex arteries than the distal sites such as the diagonal, lateral, conus, acute marginal, and posterior descending arteries. The accumulation of calcium and phosphorus in the anterior descending and right coronary arteries of the Thai increased remarkably in the fifties, thereafter decreased, and increased again in the eighties. It should be noted that a very high accumulation of calcium and phosphorus in the coronary arteries occurred in the fifties. In regard to relationships among the average contents of elements in the coronary arteries and their rami, it was found that there were very significant direct correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium contents. These results suggested that as calcium and phosphorus increased in the coronary arteries and their rami, magnesium increased simultaneously in all of the coronary arteries and their rami.     

Duplex scanning of brachiocephalic arteries and multislice spiral computed tomography of coronary arteries in the comprehensive evaluation of the arteries in women with rheumatoid arthritis

Comprehensive examination was made in women (mean age 49.6 +/- 7.4 years) with rheumatoid arthritis diagnosed abnormalities of brachiocephalic and coronary arteries in 86% of cases. Duplex scanning of brachiocephalic arteries revealed changes in 82% of the women. 64-section spiral computed tomography established coronary artery abnormalities in 33% of cases. There were isolated changes in the brachiocephalic arteries in 50% of the patients, a concomitant lesion of the brachiocephalic and coronary arteries in 32%, and isolated changes in the coronary arteries in 4%. A direct correlation was found between the index of coronary artery calcification and the intima-media thickness of brachiocephalic arteries.     

Training induces nonuniform increases in eNOS content along the coronary arterial tree.

Exercise training produces enhanced nitric oxide (NO)-dependent, endothelium-mediated vasodilator responses of porcine coronary arterioles but not conduit coronary arteries. The purpose of this study was to test the hypothesis that exercise training increases the amount of endothelial NO synthase (eNOS) in the coronary arterial microcirculation but not in the conduit coronary arteries. Miniature swine were either exercise trained or remained sedentary for 16--20 wk. Exercise-trained pigs exhibited increased skeletal muscle oxidative capacity, exercise tolerance, and heart weight-to-body weight ratios. Content of eNOS protein was determined with immunoblot analysis in conduit coronary arteries (2- to 3-mm ID), small arteries (301- to 1,000-microm ID), resistance arteries (151- to 300-microm ID), and three sizes of coronary arterioles [large (101- to 150-microm ID), intermediate (51- to 100-microm ID), and small (<50-microm ID)]. Immunoblots revealed increased eNOS protein in some sizes of coronary arteries and arterioles but not in others. Content of eNOS was increased by 60--80% in small and large arterioles, resistance arteries, and small arteries; was increased by 10--20% in intermediate-sized arterioles; and was not changed or decreased in conduit arteries. Immunohistochemistry revealed that eNOS was located in the endothelial cells in all sizes of coronary artery. We conclude that exercise training increases eNOS protein expression in a nonuniform manner throughout the coronary arterial tree. Regional differences in shear stress and intraluminal pressures during exercise training bouts may be responsible for the distribution of increased eNOS protein content in the coronary arterial tree.     

Blood Supply to the Interventricular Septum of the Heart in Rodents with Intramyocardial Coronary Arteries

The blood supply to the interventricular septum of the heart was studied in a sample of 1634 specimens belonging to four rodent families, Cricetidae, Arvicolidae, Gliridae, and Muridae. Most specimens (n = 1604) were examined using a corrosion-cast technique, while the remaining 30 were studied by histological techniques. In 1417 cases the coronary artery pattern was normal, and the interventricular septum was fundamentally supplied by one or rarely two septal arteries arising from the right and/or left coronary arteries. In 72 specimens the right and left coronary arteries were normal, while the septal artery arose from a separate ostium in the aorta, behaving as a third coronary artery. The remaining 145 animals possessed anomalies in the origin of the coronary arteries, and the septum was also principally irrigated by a septal artery. In 5 of these 145 anomalous cases the septal artery originated from a separate ostium in the aorta. In all specimens examined a less important vascularization of the septum was established through thinner penetrating vessels originating from the right and/or left coronary arteries. Existence of one or rarely two septal arteries is the most constant feature of the coronary artery arrangement in rodents with intramyocardial coronary arteries.     

Age-Related Changes of Elements in the Coronary Arteries of Monkeys in Comparison with Those of Humans

To elucidate compositional changes of the coronary artery with aging, the authors investigated age-related changes of elements in the coronary arteries of rhesus and Japanese monkeys by direct chemical analysis in comparison with the coronary arteries of Japanese and Thai. Used monkeys consisted of 38 rhesus monkeys and 23 Japanese monkeys, ranging in age from newborn to 33 years. After perfusion with a fixative, the hearts were resected from the monkeys, and the anterior interventricular branches of the left coronary artery and the right coronary arteries were resected from the hearts. After ashing of the arteries, element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that the Ca and P contents did not increase in both the left and right coronary arteries of rhesus and Japanese monkeys at old age. The average contents of Ca and P decreased by 13% and 25% in the left coronary arteries more than 20 years of age in comparison with those below 20 years of age, whereas they decreased by 4% and 15% in the right coronary arteries more than 20 years of age in comparison with those below 20 years of age. This finding indicated that atherosclerosis scarcely occurred in both the left and right coronary arteries of rhesus and Japanese monkeys at old age. In contrast with monkeys, atherosclerosis occurred frequently in the coronary arteries of Japanese and Thai at old age.     

Influence of coronary artery diameter on eNOS protein content

The purpose of this study was to test the hypothesis that the content of endothelial nitric oxide synthase (eNOS) protein (eNOS protein/g total artery protein) increases with decreasing artery diameter in the coronary arterial tree. Content of eNOS protein was determined in porcine coronary arteries with immunoblot analysis. Arteries were isolated in six size categories from each heart: large arteries [301- to 2,500-microm internal diameter (ID)], small arteries (201- to 300-microm ID), resistance arteries (151- to 200-microm ID), large arterioles (101- to 150-microm ID), intermediate arterioles (51- to 100-microm ID), and small arterioles(<50-microm ID). To obtain sufficient protein for analysis from small- and intermediate-sized arterioles, five to seven arterioles 1-2 mm in length were pooled into one sample for each animal. Results establish that the number of smooth muscle cells per endothelial cell decreases from a number of 10 to 15 in large coronary arteries to 1 in the smallest arterioles. Immunohistochemistry revealed that eNOS is located only in endothelial cells in all sizes of coronary artery and in coronary capillaries. Contrary to our hypothesis, eNOS protein content did not increase with decreasing size of coronary artery. Indeed, the smallest coronary arterioles had less eNOS protein per gram of total protein than the large coronary arteries. These results indicate that eNOS protein content is greater in the endothelial cells of conduit arteries, resistance arteries, and large arterioles than in small coronary arterioles.     

Estrogen-induced contraction of coronary arteries is mediated by superoxide generated in vascular smooth muscle

Although previous studies demonstrated beneficial effects of estrogen on cardiovascular function, the Women's Health Initiative has reported an increased incidence of coronary heart disease and stroke in postmenopausal women taking hormone replacement therapy. The objective of the present study was to identify a molecular mechanism whereby estrogen, a vasodilatory hormone, could possibly increase the risk of cardiovascular disease. Isometric contractile force recordings were performed on endothelium-denuded porcine coronary arteries, whereas molecular and fluorescence studies identified estrogen signaling molecules in coronary smooth muscle. Estrogen (1-1,000 nM) relaxed arteries in an endothelium-independent fashion; however, when arteries were pretreated with agents to uncouple nitric oxide (NO) production from NO synthase (NOS), estrogen contracted coronary arteries with an EC(50) of 7.3 +/- 4 nM. Estrogen-induced contraction was attenuated by reducing superoxide (O(2)(-)). Estrogen-stimulated O(2)(-) production was detected in NOS-uncoupled coronary myocytes. Interestingly, only the type 1 neuronal NOS isoform (nNOS) was detected in myocytes, making this protein a likely target mediating both estrogen-induced relaxation and contraction of endothelium-denuded coronary arteries. Estrogen-induced contraction was completely inhibited by 1 muM nifedipine or 10 muM indomethacin, indicating involvement of dihydropyridine-sensitive calcium channels and contractile prostaglandins. We propose that a single molecular mechanism can mediate the dual and opposite effect of estrogen on coronary arteries: by stimulating type 1 nNOS in coronary arteries, estrogen produces either vasodilation via NO or vasoconstriction via O(2)(-).     

Anomalous right coronary artery originating from the left sinus of Valsalva in a Yucatan minipig

A 39.2-kg, castrated male Yucatan minipig (Sus scrofa domestica) was presented for enrollment in a coronary artery study. Angiography revealed an anomalous right coronary artery originating from the left sinus of Valsalva. The left anterior descending, left circumflex, and anomalous right coronary arteries were implanted with metallic stents without complications. The minipig remained on the study for 3 mo until it reached its predetermined study endpoint, during which time it showed no clinical signs of disease. Histologic examination of the implanted coronary arteries revealed no differences between the normal (left anterior descending and left circumflex arteries) and the anomalous right coronary artery. Swine are important models for coronary research. Although several cases of anomalous human coronary arteries have been documented, the current case is the first report of a coronary artery anomaly in a minipig.     

Gender Difference in Accumulation of Calcium and Phosphorus in the Left Coronary Arteries of Thais

To examine whether there were gender differences in compositional changes of the coronary artery with aging, the authors investigated the gender difference in age-related changes of elements in the left coronary arteries of Thais by direct chemical analysis. After ordinary dissections by students at Chiang Mai University were finished, the left coronary arteries were resected from Thai subjects. The Thai subjects consisted of 69 men and 34 women. The ages of the male subjects ranged from 25 to 87?years (average age?=?62.6?±?11.4?years) and of the female subjects from 24 to 86?years (average age?=?59.4?±?14.6?years). After incinerating the arteries with nitric acid and perchloric acid, the element content was determined by inductively coupled plasma-atomic emission spectrometry. The Ca and P contents tended to increase in the left coronary arteries of men with age, but the increases were not statistically significant. In the left coronary arteries of women, the Ca and P contents increased significantly and progressively with aging. In addition, the Na content increased significantly in the left coronary arteries of both men and women with aging. The differences in the average contents of Ca and P by age group were observed between the left coronary arteries of men and women. With Student's t test, significant gender differences in the average contents of Ca and P were found in both the 40s and the 70s. The Ca and P contents of the left coronary arteries in the 40s were significantly higher in men than in women. In contrast, the Ca and P contents in the 70s were significantly higher in women than in men. These results indicated that the accumulation of Ca and P in the left coronary arteries of Thais occurred at least 10?years earlier in men than in women, but a higher accumulation of Ca and P in old age occurred in the left coronary arteries of women compared with those of men. The present study revealed that there were significant gender differences in the left coronary arteries with regard to the accumulation of Ca and P with aging. It is reasonable to presume that taking clinical findings into consideration, the gender differences in the left coronary arteries may result from hormonal and/or genetic factors rather than lifestyle factors.     

Selective Coronary Arteriography

The technique of selective coronary arteriography, as described originally by Sones, was employed in 255 patients. Successful catheterization of both coronary arteries was carried out in 88% of these patients, and in the last 100 examinations both coronary arteries were entered in 95 patients. Selective coronary arteriography is a useful diagnostic tool but is a potentially hazardous form of examination as we encountered four episodes of ventricular fibrillation in the present series.     

Accumulation of Calcium and Phosphorus in the Coronary Arteries of Thai Subjects

To clarify the manner of accumulation of Ca and P in the coronary arteries, the authors divided the coronary arteries into many segments based on arterial ramification and investigated the element contents of the segments by direct chemical analysis. After ordinary dissection at Chiang Mai University was finished, the left coronary (LC) and the right coronary (RC) arteries were removed successively from the hearts of Thai subjects. The Thai subjects consisted of seven men and five women, ranging in age from 42 to 87 years (average age = 73.9 ± 13.5 years). The LC and the RC arteries were divided into 19 segments based on arterial ramification. After incineration with nitric acid and perchloric acid, element contents of the segments were analyzed by inductively coupled plasma–atomic emission spectrometry. In two cases, a significant content of Ca and P was contained only in the left anterior descending (LAD) artery (type I). In four cases, a significant content of Ca and P was contained in both the LAD and the RC arteries (type II). In five cases, a significant content of Ca and P was contained in all the LAD, the RC, and the circumflex (CF) arteries (type III). In the other one case, no significant content of Ca and P was contained in the coronary arteries. The manner of accumulation of Ca and P in the coronary arteries was classified into the three types, I, II, and III. Regarding the average content of elements in 12 cases, the average content of Ca was the highest in the segment of the LAD artery ramifying the first left diagonal artery and was higher in the proximal and distal adjacent segments of the LAD artery ramifying the first left diagonal artery, the proximal segment of the RC artery, and the proximal segment of the CF artery. To examine an effect of arterial ramification on accumulation of Ca and P, the differences in the Ca and P content between artery-ramifying and non-ramified proximal or distal segments of the coronary arteries were analyzed with Student’s t test. It was found that there were no significant differences in the Ca and P content between the artery-ramifying and non-ramified proximal or distal segments of the coronary arteries.     

Anomalous course and branches of human coronary arteries

132 hearts obtained from cadavers were dissected in order to study anomalies in the course and branches of human coronary arteries. Only in 1 heart was a deviation of the circumflex branch of the left coronary artery taking a course inferior to the coronary sulcus observed. The right coronary artery travelled the entire length of the coronary sulcus on the back of the heart and gave both a posterior ventricular and a collateral branch. Circumflex branches of the right and left coronary arteries did not anastomose.     

Subepicardial endothelial cells invade the embryonic ventricle wall to form coronary arteries

Coronary arteries bring blood flow to the heart muscle. Understanding the developmental program of the coronary arteries provides insights into the treatment of coronary artery diseases. Multiple sources have been described as contributing to coronary arteries including the proepicardium, sinus venosus (SV), and endocardium. However, the developmental origins of coronary vessels are still under intense study. We have produced a new genetic tool for studying coronary development, an AplnCreER mouse line, which expresses an inducible Cre recombinase specifically in developing coronary vessels. Quantitative analysis of coronary development and timed induction of AplnCreER fate tracing showed that the progenies of subepicardial endothelial cells (ECs) both invade the compact myocardium to form coronary arteries and remain on the surface to produce veins. We found that these subepicardial ECs are the major sources of intramyocardial coronary vessels in the developing heart. In vitro explant assays indicate that the majority of these subepicardial ECs arise from endocardium of the SV and atrium, but not from ventricular endocardium. Clonal analysis of Apln-positive cells indicates that a single subepicardial EC contributes equally to both coronary arteries and veins. Collectively, these data suggested that subepicardial ECs are the major source of intramyocardial coronary arteries in the ventricle wall, and that coronary arteries and veins have a common origin in the developing heart.     

Biomechanical rationale of coronary artery bypass grafting of multivessel disease

The biomechanical model of human coronary arteries was modified for improving the quality of diagnosis and surgical treatment for coronary heart disease. The problem of hemodynamics in the left coronary artery with multivessel bed disease – 45% stenosis of the anterior descending branch and 75% stenosis of the circumflex branch – was particularly considered. Numerical simulation of the coronary arterial bypass of the main trunk was carried out to estimate the functional condition of the coronary arteries after restoring myocardial blood supply by surgery.     

Accumulation of calcium and phosphorus accompanied by increase of magnesium and decrease of sulfur in human arteries

To elucidate the accumulation of elements in the arteries with aging, the authors investigated age-related changes of elements in human arteries, such as the thoracic aorta, femoral, basilar, coronary, radial, and common iliac arteries by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 17 men and 9 women, ranging in age from 55 to 92 yr in the cases of the five arteries, except for the common iliac arteries, in which the subjects consisted of 16 men and 8 women, ranging in age from 65 to 93 yr. It was found that there were significantly direct correlations between calcium and phosphorus contents and between calcium and magnesium contents in all of the six arteries: thoracic aorta, femoral, basilar, coronary, radial, and common iliac arteries. Significantly direct correlations were also found between phosphorus and magnesium contents in the five arteries, except for the basilar artery. In contrast, significantly inverse correlations were found between calcium and sulfur contents and between phosphorus and sulfur contents in the four arteries, except for the coronary and radial arteries. These revealed that the accumulation of calcium and phosphorus in the arteries was accompanied by an increase of magnesium in the arteries and by a decrease of sulfur in the arteries.     

Age-related changes of elements in thoracic and abdominal aortas and coronary, common carotid, pulmonary, splenic, common iliac, and uterine arteries and relationships in elements among their arteries

To elucidate whether the accumulation of elements occurred simultaneously in the various arteries with aging, the authors investigated age-related changes of elements in the eight arteries, such as the thoracic and abdominal aortas and the coronary, common carotid, pulmonary, splenic, common iliac, and uterine arteries, and the relationships in the element contents among their arteries. After ordinary dissection by medical students was finished, the thoracic and abdominal aortas and the coronary, common carotid, pulmonary, splenic, common iliac, and uterine arteries were resected from the subjects, who ranged in age from 58 to 94 yr. The element contents were analyzed by inductively coupled plasma-atomic emission spectrometry. It was found that the accumulation of Ca was the highest in the common iliac artery and decreased in the order of the uterine artery, abdominal aorta, coronary artery, thoracic aorta, splenic artery, common carotid artery, and pulmonary artery. Regarding the relationships in the element contents among the eight arteries, it was found that there were significant direct correlations in the contents of Ca, P, Mg, Zn, Fe, and Na between the coronary and splenic arteries, and there were significant correlations in the contents of Ca, P, and Mg between the abdominal aorta and pulmonary artery.     

Mass ratios of magnesium to calcium and phosphorus in the arteries of Japanese and Thai

To elucidate quantitative changes of Ca, P, and Mg in the arteries with aging, the authors investigated changes of the mass ratios of Mg to Ca and P in the arteries of Japanese and Thai by inductively coupled plasma-atomic emission spectrometry. The arteries of Japanese that were used were the thoracic and abdominal aortas, coronary, common iliac, internal iliac, external iliac, and femoral arteries, in which very high accumulations of Ca and P occurred in old age. The arteries of Thai that were used were the abdominal aorta, ramifying site of the abdominal aorta, coronary, common iliac, internal iliac, and external iliac arteries. It was found that there were extremely significant correlations both between Ca and Mg contents and between P and Mg contents in all of the arteries of the Japanese and the Thai. With regard to the mass ratio, the mass ratios of Mg to Ca ranged from 1.5% to 2.1% in the six arteries of the Japanese, except for the thoracic aorta at 3.1%, at an advanced stage of atherosclerosis, being similar to each other. In the arteries of the Thai, the mass ratios of Mg to Ca ranged from 1.9% to 3.0%, except for the coronary artery at 0.5%, at an advanced stage of atherosclerosis. The mass ratios of Mg to P ranged from 2.5% to 2.7% in the six arteries of the Japanese, except for the coronary artery at 1.8%, at an advanced stage of atherosclerosis. With regard to the arteries of the Thai, the mass ratios of Mg to P ranged from 1.9% to 3.3%, except for the coronary artery at 0.7%, at an advanced stage of atherosclerosis. These results revealed that both the mass ratios of Mg to Ca and Mg to P were almost similar among the arteries of Japanese and Thai, except for the coronary arteries. Therefore, these results suggested that the inorganic deposits in the coronary arteries of Japanese and Thai were similar to those in the intimal tunica of the thoracic aorta, whereas in the other arteries, they were similar to those in the middle tunica of the thoracic aorta.     

Role of ceramide in TNF-alpha-induced impairment of endothelium-dependent vasorelaxation in coronary arteries

The present study tested the hypothesis that ceramide, a sphingomylinase metabolite, serves as an second messenger for tumor necrosis factor-alpha (TNF-alpha) to stimulate superoxide production, thereby decreasing endothelium-dependent vasorelaxation in coronary arteries. In isolated bovine small coronary arteries, TNF-alpha (1 ng/ml) markedly attenuated vasodilator responses to bradykinin and A-23187. In the presence of N(G)-nitro-L-arginine methyl ester, TNF-alpha produced no further inhibition on the vasorelaxation induced by these vasodilators. With the use of 4,5-diaminofluorescein diacetate fluorescence imaging analysis, bradykinin was found to increase nitric oxide (NO) concentrations in the endothelium of isolated bovine small coronary arteries, which was inhibited by TNF-alpha. Pretreatment of the arteries with desipramine (10 microM), an inhibitor of acidic sphingomyelinase, tiron (1 mM), a superoxide scavenger, and polyethylene glycol-superoxide dismutase (100 U/ml) largely restored the inhibitory effect of TNF-alpha on bradykinin- and A-23187-induced vasorelaxation. In addition, TNF-alpha activated acidic sphingomyelinase and increased ceramide levels in coronary endothelial cells. We conclude that TNF-alpha inhibits NO-mediated endothelium-dependent vasorelaxation in small coronary arteries via sphingomyelinase activation and consequent superoxide production in endothelial cells.     

Identification of an alpha 2-adrenoceptor in human coronary arteries by radioligand binding assay.

A single high affinity binding site for an alpha 2-adrenoceptor in human coronary arteries was identified by radioligand binding assay. Human coronary arteries were obtained at autopsy within 6 hours of death. A crude membrane solution was incubated with (3H)-rauwolscine at 25 degrees C for 30 min. The binding of (3H)-rauwolscine was rapidly saturable and reversible. Kd was 1.2 +/- 0.2 (SE) nM and Bmax 22 +/- 3 fmol/mg protein. This is the first study which has shown the presence of an alpha 2-adrenoceptor in human coronary arteries using a radioligand binding assay method.     

猪冠状动脉的解剖学观察

本文对50例健康的商品猪心脏的铸型标本进行了观察,结果如下:左冠状动脉旋枝与锥旁室间枝的夹角为74.4±2.07度。对角枝出现率为24％,并证明了对角枝出现率与其夹角大小呈正比关系。窦房结枝84％来自右冠状动脉。房室结枝98％来自右冠状动脉。左房旋枝出现率为8％。室间隔的供血由锥旁室间枝的分枝负担61％,约为3/5,窦下室间枝的分技负担39％,约为2/5。室上嵴技、Kugel动脉、室间隔中枝和室间隔背倒前枝的出现率分别为78％、20％、68％和28％。心尖区的血液由左、右冠状动脉共同供应。50例左、右冠状动脉始部外径之比为1.2∶1。左、右冠状动脉在心膈面的分布类型以右强型为主。本文还讨论了猪冠状动脉与狗、人冠状动脉的异同。