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.     

High accumulation of elements in the human femoral artery

The relative contents (RCs) of elements in the femoral arteries as well as the thoracic aorta, coronary, basilar, and radial arteries from 26 subjects within the age range between 55 and 92 yr old, were analyzed by inductively coupled plasma atomic emission spectrometry. The RCs of calcium and phosphorus in the femoral arteries started to increase before the age of 60 yr. The RCs of magnesium increased after the age of 70 yr. However, the RCs of sulfur did not change significantly within the age range between 55 and 92 yr. With regard to localization of the mineral accumulations in the femoral arterial wall, it was found that the accumulations of calcium and phosphorus occurred only in the tunica media, only in the tunica intima, or in both the tunica media and the tunica intima. The manner of accumulation of calcium and phosphorus in the femoral arterial wall was different from that in the aortic wall. The average RCs of calcium in the 26 specimens were the highest in the femoral artery, followed in descending order by the thoracic aorta, coronary, basilar, and radial arteries. The average RCs of phosphorus were highest in the thoracic aorta, followed by the coronary, femoral, basilar, and radial arteries. It is noted that the accumulation of mineral elements never occurred uniformly in all 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.     

Earlier accumulation of calcium, phosphorus, and magnesium in the coronary artery in comparison with the ascending aorta, aortic valve, and mitral valve

To explore reasons for a high accumulation of Ca and P occurring in the coronary artery of Thai with aging, the authors investigated age-related changes of elements in the coronary artery, ascending aorta near the heart, and cardiac valves in single individuals, and the relationships in the elements between the coronary artery and either the ascending aorta or cardiac valves. After an ordinary dissection by medical students at Chiang Mai University was finished, the anterior descending arteries of the left coronary artery, ascending aortas, mitral valves, and aortic valves were resected from the subjects. The subjects consisted of 17 men and 9 women, ranging in age from 46 to 76 yr. The element content was analyzed by inductively coupled plasma-atomic emission spectrometry. The average content of Ca and P was the highest in the coronary artery and decreased in the order aortic valve, ascending aorta, and mitral valve. The Ca, P, and Mg content increased in the coronary artery in the fifties and in the ascending aorta, aortic valve, and mitral valve in the sixties. It should be noted that the accumulation of Ca, P, and Mg occurred earlier in the coronary artery than in the ascending aorta, aortic valve, and mitral valve. It was found that with respect to the Ca, P, Mg, and Na contents, the coronary artery correlated well with both the aortic valve and ascending aorta, especially with the aortic valve, but it did not correlate with the mitral valves. This finding suggests that the accumulation of Ca, P, Mg, and Na occurs in the coronary artery together with the aortic valve and ascending aorta, but not together with the mitral valve. Because regarding the accumulation of Ca, P, and Mg, the ascending aorta and aortic valve are preceded by the coronary artery, it is unlikely that the accumulation of Ca, P, and Mg spreads from the ascending aorta or aortic valve to the coronary artery.     

Age-dependent Increases of Calcium, Phosphorus, and Sodium in the Uterine Arteries of Thai

To elucidate compositional changes of the uterine artery with aging, the authors investigated age-related changes of elements in the uterine arteries of Thai. After ordinary dissection by medical students at Chiang Mai University was finished, the uterine arteries were resected from Thai subjects. Thai subjects ranged in age from 27 to 86 years (average age = 63.3 +/- 17.7 years). The element content of the uterine arteries was analyzed by inductively coupled plasma-atomic emission spectrometry. It was found that the Ca, P, and Na contents increased progressively in the uterine arteries of Thai with aging. A significant accumulation of Ca and P in the uterine arteries of Thai was found in the sixties patients, and the accumulation increased markedly in the seventies. Regarding the uterine arteries in subjects more than 60 years, the extent of accumulation of Ca and P in the uterine arteries of Thai was one half of that in the uterine arteries of Japanese. Regarding the relationships among elements, extremely significant direct correlations were found among the contents of Ca, P, Mg, Zn, and Na in the uterine arteries of Thai. As Ca increased in the uterine arteries of Thai, P, Mg, Zn, and Na increased simultaneously in the arteries.     

Age-dependent aluminum accumulation in the human aorta and cerebral artery

The purpose of this study was to determine the extent of aluminum (Al) accumulation in the human aorta and cerebral arteries. The Al contents in the aortae and in the cerebral arteries from 23 human subjects was determined by inductively coupled plasma atomic emission spectrophotometry (ICP-AES). The subjects' age range was 45–99-yr-old; 15 of the subjects were males and 8 were females. Al was detected in twelve aortae and in six cerebral arteries, when the entire specimen was analyzed. Two specimens where Al was found in the cerebral arteries contained no Al in the aorta. No relationship to the subject's sex was found. When related to age, two groups were established. Group L (45–75 yr old) and group H (>75 yr old), which exhibited aortal Al concentrations of 33.3 and 72.7%, respectively. When the aortic wall was dissected into the tunica intima, media, and adventitia, Al was found mainly in the tunica media. In the aorta, significant relationships were found between Al and phosphorus (P) levels (r=0.801,p<0.01) and between Al and calcium (Ca) (r=0.661,p<0.05). We have concluded that Al accumulation is age-dependent and that it occurs both in the aorta and in the cerebral artery. In the aorta, accumulation occurs mainly in the tunica media. Both P and Ca appear to enhance aortal Al accumulation.     

Moderate Accumulation of Calcium and Phosphorus in the Splenic Artery with Aging and Low Accumulation of Those in the Pulmonary Artery with Aging

To elucidate compositional changes of the arteries with aging, the authors investigated age-related changes of elements in the splenic and pulmonary arteries, which supplied blood to contractile organs. After ordinary dissection by medical students at Nara Medical University was finished, the splenic and pulmonary arteries were resected from the subjects, ranging in age from 58 to 94 years. The element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that a moderate accumulation of Ca and P occurred in the splenic artery with aging, but it hardly occurred in the pulmonary artery with aging. Regarding the relationship among elements, the finding that there were significant direct correlations among the contents of Ca, P, Mg, and Na was commonly obtained in both the splenic and pulmonary arteries. The accumulation of Ca and P in the splenic artery with aging occurred independently of that in the pulmonary artery. Histologic observation indicated that a major part of Ca deposits was seen in the middle tunica, but not in the internal tunica. Therefore, the calcification occurring in the splenic artery belonged to middle sclerosis.     

Increases of calcium and phosphorus in the uterine arteries with aging

To elucidate compositional changes of the uterine artery with aging, the authors investigated age-related changes of elements in the uterine arteries. After ordinary dissection by medical students at Nara Medical University was finished, the uterine arteries were resected from the subjects. The element content of the uterine arteries was analyzed by inductively coupled plasma-atomic emission spectrometry. The subjects ranged in age from 58 to 99 yr (average age=82.7±10.1 yr). It was found that the Ca, P, and Na contents increased progressively in the uterine arteries with aging. A significant accumulation of Ca and P in the uterine arteries was found in the sixties and increased markedly in the eighties. It should be noted that as far as the arteries in those over 70 yr of age, the extent of accumulation of Ca and P was the highest in the uterine arteries within the limits of the arteries analyzed by us. Regarding the relationships among elements, significant direct correlations were found among the contents of Ca, P, Mg, Zn, and Na. As Ca increased in the uterine arteries, P, Mg, Zn, and Na increased simultaneously in the arteries.     

Scarce Occurrence of Calcification in Human Sinoatrial Nodal Arteries in Old Age

To elucidate age-related changes of the sinoatrial (sinuatrial) nodal (SAN) artery, the authors investigated age-related changes of elements in the SAN artery by direct chemical analysis. In addition, the effects of different arterial origins, arterial sizes, and genders on element accumulation were investigated in the SAN artery. Fifty-nine formalin-fixed adult Thai hearts were dissected, and the following three types of the SAN artery were found: The first type was a single SAN artery arising from the right coronary artery (RCA). The second type was a single SAN artery arising from the proximal segment of the left circumflex artery (LCX). The third type was dual SAN artery arising from both the RCA and the LCX. For element analysis, both 41 single SAN arteries arising from the RCA and the LCX and 18 larger branches of dual SAN artery were used. After the arteries were incinerated with nitric acid and perchloric acid, element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that seven element contents such as Ca, P, S, Mg, Zn, Fe, and Na did not change significantly in the SAN arteries with aging. Regarding the relationships among seven elements in the SAN arteries, extremely significant direct correlations were found among P, S, Mg, and Fe contents with one exception. However, no significant correlations were found between Ca and either P or Mg contents in the SAN arteries. To examine an effect of the different arterial origins on element accumulation, the SAN arteries were separated into the RCA and the LCX groups by the arterial origin and age-related changes of element contents were compared between two groups. It was found that there were no significant differences between the RCA and the LCX groups in age-related changes of Ca and P contents. No gender differences were found in age-related changes of Ca and P contents in the SAN arteries. To elucidate whether calcification occurred in the SAN arteries in old age, both the mass ratios of Ca/P and Mg/Ca were estimated in the SAN arteries. The mass ratio of Ca/P increased progressively in the SAN arteries with Ca increase, being not constant. The mass ratio of Mg/Ca decreased gradually in the SAN arteries with Ca increase, but the average mass ratio of Mg/Ca was very high, being 49.4 ± 16.5%. These results indicated that calcification scarcely occurred in the SAN arteries in old age, independently of the arterial origin and gender.     

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.     

不同竹龄雷竹中硅及其他营养元素吸收和积累特征

在浙江省临安市的雷竹主产区,分别采集不同竹龄(1～4 a)和不同器官(叶、枝、秆)的雷竹样品,分析了Si和其他营养元素含量、吸收和积累特征,以及Si和其他营养元素之间的相互关系.结果表明： 雷竹各器官中C含量的大小顺序为竹秆>竹枝>竹叶,Si、N、P、K、Ca、Mg、Al、Fe和Mn含量的大小顺序为竹叶>竹枝>竹秆.除Mn主要积累在竹叶中外,其他9种营养元素主要积累在1年生雷竹的秆中.3～4年生雷竹竹叶的Si平均含量为13.66 g · kg^-1. 雷竹属于Si积累植物.随竹龄的增加,雷竹叶中的N、P、K和Mg含量减少,C、Al和Mn含量增加.雷竹对Si的吸收主要集中在第2年(57.1%),对N和K的吸收主要集中在前两年(67.7%～93.7%),此后N和K从植株体内流出,其流失量分别占总积累量的19.1%～39.1%.雷竹中Si与Ca、Al、Mn呈显著正相关,与N、P、K、Mg呈显著负相关.     

Characterization of the contractile P2Y14 receptor in mouse coronary and cerebral arteries

Extracellular UDP-glucose can activate the purinergic P2Y14 receptor. The aim of the present study was to examine the physiological importance of P2Y14 receptors in the vasculature. The data presented herein show that UDP-glucose causes contraction in mouse coronary and basilar arteries. The EC₅₀ values and immunohistochemistry illustrated the strongest P2Y14 receptor expression in the basilar artery. In the presence of pertussis toxin, UDP-glucose inhibited contraction in coronary arteries and in the basilar artery it surprisingly caused relaxation. After organ culture of the coronary artery, the EC₅₀ value decreased and an increased staining for the P2Y14 receptor was observed, showing receptor plasticity.     

Distribution of the vasoconstrictor and vasorelaxant effects of norbormide along the vascular tree of the rat

Norbormide is a vasoconstrictor of rat peripheral arteries and a relaxant in rat aorta. To characterise norbormide actions within the rat vascular tree we have investigated its effects on the contractile function of rings from several arteries and veins. A maximal norbormide concentration (50 microM) failed to contract thoracic aorta and carotid artery, whereas in pulmonary artery, abdominal aorta, iliac, caudal, and femoral arteries it induced a contractile effect that was respectively 4.8 +/- 0.6, 18.4 +/- 1.5, 39 +/- 5, 144 +/- 7, and 260 +/- 22% of that induced by 90 mM KCl. In pulmonary, carotid, and iliac arteries, and in thoracic and abdominal aorta, 50 microM norbormide inhibited KCl-induced responses. Norbormide (50 microM) contracted all veins investigated. The effect, expressed as % of KCl-induced contraction, was 121 +/- 25, 154 +/- 14.5, 154 +/- 18.2, 203 +/- 19, and 267 +/- 33 for pulmonary vein, thoracic and abdominal vena cava, iliac and jugular veins, respectively. In jugular vein, as previously shown in rat caudal artery, norbormide contraction was abolished in Ca2+-free medium, was unaffected by the Ca2+ channel blocker nifedipine, and was relaxed by SK&F 96365, a blocker of store-operated Ca2+ channels. In conclusion: i) rat veins represent the main target for contractile norbormide action; ii) in both artery and veins norbormide contractions are generally inversely related to the calibre of the vessel; iii) norbormide-induced contraction is mediated by the same mechanism/s in arteries and veins; iiii) in norbormide-contracted arteries the drug activates both contractile and relaxing mechanisms.     

Accumulation of elements in the arteries and cardiac valves of Thai with aging

To elucidate whether the extent of element accumulation in the arteries and cardiac valves with aging was different between different races, the authors investigated the accumulation of elements in the arteries and cardiac valves of the Thai with aging and the relationships among elements in the cardiac valves. After ordinary dissection at Chiang Mai University was finished, 16 arteries and 4 cardiac valves were resected and element contents were determined by inductively coupled plasma-atomic emission spectrometry. In the 16 arteries, the average content of calcium was the highest in the site of the abdominal aorta ramifying into the common iliac arteries, and it decreased in the order internal iliac, coronary, abdominal aorta, common iliac, external iliac, superior mesenteric, inferior mesenteric, thoracic aorta, brachial, radial, common carotid, subclavian, ulnar, axillary, renal, and internal thoracic arteries. The average contents of phosphorus and magnesium in respective arteries were parallel with the average contents of calcium, except for the coronary artery. In comparison with the arteries of the Japanese, the trend of calcium accumulation in the arteries of the Thai was almost similar to that in the arteries of the Japanese, except for the coronary artery and thoracic aorta. The calcium accumulation in the coronary artery was much higher in the Thai than in the Japanese, whereas that in the thoracic aorta was lower in the Thai than in the Japanese. Regarding elements in the cardiac valves, the calcium content increased remarkably in the seventies in the aortic valve and in the nineties in the pulmonary valve, but it hardly increased in both the mitral and tricuspid valves with aging. The average content of calcium was the highest in the aortic valve, and it decreased in the order pulmonary, tricuspid, and mitral valves. Regarding the relationship among elements in the aortic valves, it was found that there were extremely significant direct correlations among the contents of calcium, phosphorus, and magnesium, whereas there were significant direct correlations between zinc and either calcium or phosphorus contents. Although significant correlations were found between sulfur and the other element contents in the aortic valves of the Japanese, no significant correlations were found between them in the aortic valves of the Thai. In the mitral valves, extremely or very significant direct correlations were found among the contents of calcium, phosphorus, magnesium, and sulfur, with some exceptions that there were no significant correlations between phosphorus and either magnesium or sulfur contents. In addition, no significant correlation was found in the calcium content between the aortic valve and coronary artery in the same individuals.     

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.     

Age-related changes of elements with their relationships in human cranial and spinal nerves

To elucidate compositional changes of peripheral nerves with aging, the authors investigated age-related changes of elements and their relationships in the optic, trigeminal, vagus, median, radial, ulnar, femoral, sciatic, tibial, and common peroneal nerves by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 10 men and 12 women, ranging in age from 65 to 91 yr. It was found that although accumulations of Ca and P occurred only in the trigeminal nerve at old age, it hardly occurred in the optic, vagus, median, radial, ulnar, femoral, sciatic, tibial, and common peroneal nerves at old age. The average contents of Ca and P were three and two times higher in the trigeminal nerve than in the other nine kinds of nerve, respectively. Likewise, the average content of Mg was a little higher in the trigeminal nerve compared with the other nerves. With regard to the relationships among elements, significant direct correlations were found among the contents of Ca, P, S, and Mg in most, but not all, 10 kinds of nerve. In the trigeminal nerve, a significant inverse correlation was found between the contents of S and the other elements, such as Ca, P, and Mg. Regarding the relationships between the contents of S and other elements, the nerves, except for the trigeminal nerve, differed from those found in the arteries previously reported.     

The inhibitory actions of acebutolol and propranolol on the contractile response to 5-hydroxytryptamine in various isolated vascular smooth muscles

Pretreatment with acebutolol or propranolol at high concentrations had an inhibitory effect on the contractile response to 5-hydroxytryptamine (5-HT) in most vascular smooth muscles such as rabbit aorta and basilar, mesenteric, renal, femoral arteries and cat coronary artery. The inhibitory actions of both agents were generally greater than on the responses to excess Ca2+ and potassium. In rabbit renal arteries, acebutolol had no effect on the response to 5-HT but inhibited the responses to excess Ca2+ and potassium. Propranolol had a marked inhibitory effect on the response to 5-HT. In all preparations used, the contractions induced by norepinephrine (NE) and histamine showed a much greater resistance to the effect of acebutolol and propranolol than the contractions induced by 5-HT, Ca2+ and potassium. Nifedipine had no inhibitory effect on the response to 5-HT in most of the preparations. Nifedipine inhibited the response to 5-HT only in the basilar arteries. The inhibitory actions of propranolol on the response to 5-HT was greater than that of acebutolol. The inhibitory action of acebutolol and propranolol on the response to 5-HT may be related to mechanisms other than the beta-adrenoceptor blocking action of the drugs. The possible mechanisms of inhibitory action of both beta-adrenoceptor antagonists on 5-HT are discussed.     

应用电子探针对植物根际和根内营养元素微区分布的探讨

用电子探针可检测出玉米、大豆根际和根内含有Na,Mg,Al,Si,P,S,Cl,K,Ca,Ti,Fe,Cu和Zn 13种元素。这些元素在根际土壤、粘液层和根组织内的含量分布有一定的规律性。除Si,Al,Ca,Fe在根际土壤中峰值较高外,Ti仅在土壤中达到可检测量;S,Fe和Zn富集在粘液层,Mg,P,Cl只在根组织内才有较明显的峰。这些规律可作为区分根—土界面的参考指标。K含量在根内明显高于根际土壤,并由表皮层到中柱径向增加;Ca则与K不同,且受植物种类的影响。     

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.