High Accumulation of Calcium and Phosphorus in the Pineal Bodies with Aging

To elucidate compositional changes of the pineal body with aging, the authors investigated age-related changes of elements in the pineal body. After the ordinary dissection by medical students was finished, the pineal bodies and seven 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 high accumulation of Ca and P occurred in the pineal bodies with aging. Regarding the relationships among the elements, it was found that there were significant direct correlations among the contents of Ca, P, and Mg. With regard to the relationships between the pineal body and the arteries, no significant correlations were found in the Ca content between the pineal body and the arteries, such as the thoracic and abdominal aortas and the coronary, common carotid, pulmonary, splenic, and common iliac 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.     

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.     

Marginal Zinc Deficiency Increases Magnesium Retention and Impairs Calcium Utilization in Rats

An experiment with rats was conducted to determine whether magnesium retention is increased and calcium utilization is altered by a marginal zinc deficiency and whether increased oxidative stress induced by a marginal copper deficiency exacerbated responses to a marginal zinc deficiency. Weanling rats were assigned to six groups of ten with dietary treatment variables of low zinc (5 mg/kg for 2 weeks and 8 mg/kg for 7 weeks), low copper (1.5 mg/kg), adequate zinc (15 mg/kg), and adequate copper (6 mg/kg). Two groups of rats were fed the adequate-zinc diet with low or adequate copper and pair-fed with corresponding rats fed the low-zinc diet. When compared to the pair-fed rats, marginal zinc deficiency significantly decreased the urinary excretion of magnesium and calcium, increased the concentrations of magnesium and calcium in the tibia, increased the concentration of magnesium in the kidney, and increased the urinary excretion of helical peptide (bone breakdown product). Marginal copper deficiency decreased extracellular superoxide dismutase and glutathione, which suggests increased oxidative stress. None of the variables responding to the marginal zinc deficiency were significantly altered by the marginal copper deficiency. The findings in the present experiment suggest that increased magnesium retention and impaired calcium utilization are indicators of marginal zinc deficiency. Mention of a trademark or proprietary product does not constitute a guarantee or warranty by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that also might be suitable. The U.S. Department of Agriculture, Agricultural Research Service, Northern Plains Area is an equal opportunity/affirmative action employer, and all agency services are available without discrimination.     

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.     

饲料钙磷含量和钙磷比对生长期大鼠体重增长与骨骼发育的影响

目的研究饲料中不同的钙磷含量和钙磷比对生长期实验大鼠体重及骨骼发育的影响。方法采用完全随机化设计方案,取1月龄（100±10）g清洁级Wistar雄性大鼠70只,随机分成7组,每组10只,饲喂7种不同钙磷含量的饲料。自由采食,饮用去离子水,试验期42 d。各组于实验开始和结束时称重。试验结束后,处死动物并分离一侧胫骨和股骨用于实验指标的检测。结果当保持饲料中钙或者磷中的一种含量不变的情况下,调整另一种的含量即改变钙磷比例时,1.2∶1的正常钙磷比例组生长期实验大鼠增重及骨骼发育要明显好于0.4∶1的低钙磷比例组和4∶1的高钙磷比例组（P〈0.05）,并且当保持饲料中钙磷比例不变时,即使在低钙低磷和高钙高磷进食水平下,正常钙磷比例组大鼠增重及骨骼发育都较好,但低钙磷比例组和高钙磷比例组大鼠增重及骨骼发育则由于饲料中钙磷含量的变化波动较大（P〈0.05）。结论饲料中钙和磷需按比例添加,如果两者绝对含量相差过大就会影响到动物的增重及骨骼发育,本实验证明饲料钙磷比为1.2∶1时生长期实验大鼠增重及骨骼发育较好。     

子宫压迫缝合联合子宫动脉结扎术治疗产后出血的临床疗效

目的:探讨子宫压迫缝合联合子宫动脉结扎术治疗产后出血的临床疗效。方法:选取近年来60名产后出血患者,30名患者用子宫压迫缝合术(对照组),另外30名用子宫压迫缝合联合子宫动脉结扎术(实验组),观察手术时间、术后出血量及临床疗效。结果:实验组有效率为86.67%,对照组有效率为83.33%,两组患者的临床疗效差异无统计学意义(P0.05);两组手术时间,术中出血量差异无统计学意义(P0.05),但实验组的术后2 h出血量比对照组少,差异有统计学意义(P0.05)。结论:子宫压迫缝合联合子宫动脉结扎术治疗产后出血疗效显著,值得在临床上推广。     

Age-dependent increase of magnesium in the cerebral arteries of Thai

To elucidate compositional changes of the cerebral arteries with aging, the authors investigated age-related changes of elements in the cerebral arteries by inductively coupled plasma-atomic emission spectrometry (ICP-AES). After an ordinary dissection by medical students at Chiang Mai University was finished, the anterior, middle, and posterior cerebral arteries and the anterior and posterior communicating arteries were resected from the subjects. The subjects consisted of six men and seven women, ranging in age from 34 to 86 yr. The element content was determined by ICP-AES. It was found that the Mg content increased progressively with aging in all of the anterior, middle, and posterior cerebral arteries, but the Ca and P content did not increase significantly with aging in the anterior, middle, and posterior cerebral arteries, with the one exception being that the P content increased significantly in the posterior cerebral arteries with aging. The average content of Ca was higher in the order of the anterior communicating, anterior cerebral, posterior communicating, posterior cerebral, and middle cerebral arteries.     

钙、磷摄入对骨代谢及骨组织形态影响的研究进展

骨代谢始终贯穿于动物的生命过程之中,而机体摄入的钙、磷水平和钙、磷比例又是骨代谢的重要影响因素。钙、磷摄入水平和比例的改变会使甲状旁腺激素（PTH）、降钙素（CT）和1α,25-双羟维生素D3[1,25-（OH）2D3]的水平产生变化,影响RANK／RANKL／OPG系统对骨细胞功能的调控,进而对骨代谢及骨组织形态产生影响。骨唾液酸蛋白（Bone Sialoprotein,BSP）是目前评价成骨细胞分化和骨骼矿化情况的新指标,研究BSP表达水平的变化规律,可以从分子水平解释钙、磷摄入水平和比例对骨组织形态影响的机理。而骨组织形态计量学（Bone Histomorphometry）则是研究钙、磷摄入水平和比例对骨组织形态影响的重要方法。     

Patterns of mobilization of calcium,magnesium, and phosphorus by embryonic yellow-headed blackbirds(Xanthocephalus xanthocephalus)

Summary Embryonic blackbirds(Xanthocephalus xanthocephalus) obtain most of their calcium from the eggshell (85 90%), but all of their phosphorus comes from reserves in the yolk (80–85%) and albumen (15–20%). Approximately equal amounts of magnesium are supplied by the eggshell, the yolk, and the albumen. Yolk is depleted of magnesium and phosphorus during embryogenesis, but excess calcium absorbed from the eggeshell is stored in the yolk. Consequently reserves of calcium in the yolk actually increase 8-fold during embryonic development. Our results reveal that altricial birds manifest patterns of mobilization and deposition of calcium and other elements similar to those described for precocial species. Evolution of altriciality from precocity evidently did not entail major changes in how embryonic birds meet the challenge of obtaining the calcium, magnesium, and phosphorus required for development.     

血清VEGF，IGF-1和CA125水平与子宫动脉栓塞术(UAE)治疗子宫腺肌症的相关性

目的:探讨血清血管内皮生长因子(VEGF)、胰岛素样生长因子-1(IGF-1)和CA125水平和子宫动脉栓塞术(UAE)治疗子宫腺肌症的之间的相关性。方法:选择接受子宫动脉栓塞术治疗的39例子宫腺肌症患者作为患者组,取同时期参加健康体检的30名健康者作为健康对照组。用ELISA法检测子宫腺肌症患者子宫动脉栓塞术前和术后不同时点血清VEGF、IGF-1、CA125的水平,评估子宫动脉栓塞术后的患者的疗效。结果:34例痛经患者术后1个月开始改善,最终29例完全缓解,有效率85.2%。患者组治疗前血清VEGF、IGF-1、CA125水平均显著高于健康对照组(P0.05)。子宫动脉栓塞术治疗后,患者组血清IGF-1、VEGF和CA125的水平与治疗前相比均显著降低,术后6月,恢复正常水平。结论:血清IGF-1、VEGF、CA125的变化可能在子宫动脉栓塞术治疗子宫腺肌症中作为疗效和预后评估指标。     

Comparative Study on the Effect of Variable Phosphorus Intake at two Different Calcium Levels on P Excretion and P Flow at the Terminal Ileum of Laying Hens

A 3 ‐ 2-factorial balance trial was conducted with dietary concentrations of P below the requirement (3.6, 4.3 and 5.0g/kg DM) and Ca below or at the requirement (28 and 37g/kg DM) adjusted by monobasic calcium phosphate (MCP, Ca(H₂PO₄)₂) and calcium carbonate (CaCO₃). The diets were mainly based on maize and soybean meal. Six 18-week old laying hens were allocated to each of the diets, and excreta were quantitatively collected for 21 days from week 22 of age onwards. Feed allowance was 95 g/d according to pre-treatment ad libitum intake of the hens receiving the lowest P concentration. After the balance trial was terminated, ileal digesta was obtained from each hen, and the flow at the terminal ileum was calculated using TiO₂ as indigestible marker. Linear regression analysis was applied to determine the effect of supplementary P. Hens were in a negative energy balance, indicated by a loss in BW across all treatments. Intake and excretion of both N and energy were not significantly affected by the P or Ca content of the diet. P from supplemented MCP was almost completely recovered in excreta, irrespective of dietary Ca concentration. At the terminal ileum, however, the P flow was not significantly affected by the MCP supplementation. Net absorption of P from MCP was almost complete until the terminal ileum, but P was re-directed into the excreta, likewise via the urine. The supplementation of Ca reduced praecaecal net absorption and utilisation of P from the basal diet, likewise due to a reduced phytate hydrolysis. It is suggested by the data, that comparative measurements of P availability for laying hens should be conducted on the basis of praecaecal net absorption rather than on total excretion measurements.     

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.     

Age-Related Changes of the Concentrations of Select Elements in the Prostates of Japanese

To elucidate compositional changes of the prostate with aging, the authors investigated age-related changes of elements in the prostates and the relationships among their elements using Japanese and Thai. After ordinary dissections by students at Nara Medical University and Chiang Mai University were finished, the prostates were resected from the subjects. Fifty-seven Japanese subjects ranged in age from 65 to 101 years (average age = 82.5 ± 7.8 years), whereas 13 Thai subjects ranged in age from 43 to 86 years (average age = 67.9 ± 11.9 years). After ashing with nitric acid and perchloric acid, element contents were determined by inductively coupled plasma–atomic emission spectrometry. It was found that although there were no significant correlations between age and seven element contents, such as Ca, P, S, Mg, Zn, Fe, and Na, in the prostates of Japanese, high contents of Ca (>5 mg/g) and P (>4 mg/g) were contained in one fourth of the prostates of Japanese over 70 years of age. In the prostates of Thai, a significant direct correlation was found between age and Ca content, but it was not found between age and the other element contents, such as P, S, Mg, Zn, Fe, and Na. Regarding the relationships among their elements, extremely significant direct correlations were found among the contents of Ca, P, Mg, Zn, and Na in the prostates of Japanese. In the prostates of Thai, significant direct correlations were found among the contents of Ca, Mg, and Zn, but no significant correlations were found between Ca and P contents and between P and Mg contents. Regarding the relationships among their elements, there were differences between the prostates of Japanese and Thai. To examine whether element contents changed in prostatic hypertrophy, the transverse width of the Japanese prostates was measured. No significant correlations were found between the transverse width and element contents, such as Ca, P, S, Mg, Zn, Fe, and Na, in the Japanese prostates. Therefore, it is unlikely that the increase of elements results in prostatic hypertrophy.     

Regional Calcium Accumulation and Cation Shifts in Rat Brain by Kainate

Abstract: Following local application of kainic acid, changes in the contents of Na⁺, K⁺, Ca²⁺, and Mg²⁺ of the striatum, cerebellum, and hippocampus of the rat were observed at various times after surgery. Within 1 h the levels of K⁺ decreased 20% whereas the levels of Na⁺ and Ca²⁺ increased at least 50% and 20%, respectively. These changes persisted for more than 8 weeks. Ca²⁺ levels rose further, to more than 10-fold during 8 weeks. The Mg²⁺ levels were slightly and only transiently decreased. Unilateral injections of kainate into the striatum affected the contents of these cations not only in this area, but also in the overlying cerebral cortex, the olfactory tubercle, and the ipsilateral substantia nigra. The Ca²⁺ increases were less when rats were kept on a diet deficient in Ca²⁺ and vitamin D. ⁴⁵Ca²⁺, intravenously administered, accumulated significantly more in the kainate-lesioned striatum and substantia nigra than in the homotopic contralateral areas. Electron microscopic examination of the localization of Ca²⁺ with the oxalate-pyroantimonate technique showed the appearance of extracellularly located deposits and the accumulation of Ca²⁺ in (possibly degenerating) myelinated axons in kainate-lesioned striata. This study provides evidence that calcification of cerebral tissue is closely associated with neurodegenerative processes and shows that kainate may serve as a tool to elucidate the mechanism of brain calcification. The results are discussed in relation to idiopathic calcinosis (striopallidodentate calcinosis, Fahr's disease).     

硫酸镁联合小剂量阿司匹林治疗子痫前期效果及子宫动脉血流、胎盘VEGF、MMP-9表达影响研究

摘要 目的：探讨硫酸镁联合小剂量阿司匹林治疗子痫前期效果及子宫动脉血流、胎盘血管内皮生长因子（VEGF）、基质金属蛋白酶-9（MMP-9）表达影响研究。方法：选择2019年6月-2021年1月在我院接受治疗的125例子痫前期患者,采用随机数表法分为试验组（n=63）和对照组（n=62）。对照组给硫酸镁治疗,试验组在对照组的基础上联合小剂量阿司匹林治疗。比较两组临床疗效、子宫动脉血流、胎盘VEGF、MMP-9、血压水平变化情况及妊娠不良结局发生情况。结果：治疗后,两组总有效率比较差异显著（P<0.05）;治疗前,试验组和对照组子宫动脉指标水平比较无显著差异;治疗后,试验组和对照组RI、PI及S/D水平均随着时间的推移而升高,且试验组均高于对照组,差异显著（P<0.05）;治疗前,试验组和对照组胎盘VEGF、MMP-9水平比较无显著差异;治疗后,试验组和对照组胎盘VEGF、MMP-9水平均随着时间的推移而升高,且试验组均高于对照组,差异显著（P<0.05）;治疗前,试验组和对照组血压水平比较无显著差异;治疗后,试验组和对照组血压水平均随着时间的推移而降低,且试验组均低于对照组,差异显著（P<0.05）;试验组胎儿窘迫、宫缩乏力及新生儿窒息发生率均显著低于对照组,差异显著（P<0.05）。结论：在子痫前期中应用硫酸镁联合小剂量阿司匹林治疗疗效显著,可有效改善患者子宫动脉血流、胎盘VEGF、MMP-9水平。     

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.     

骨化三醇联合常规治疗对慢性肾脏病患者肾功能、炎性因子及钙磷代谢的影响

目的:探讨骨化三醇联合常规治疗对慢性肾脏病(CKD)患者肾功能、炎性因子及钙磷代谢的影响。方法:选取2016年2月~2019年2月我院收治的CKD患者103例,根据随机数字表法将患者分为对照组(n=51)和研究组(n=52),其中对照组给予常规治疗,研究组在对照组基础上联合骨化三醇治疗,比较两组患者肾功能指标、炎性因子及钙磷代谢水平,记录两组治疗期间不良反应发生情况。结果:两组患者治疗3个月后尿素氮(BUN)、血肌酐(SCr)、24 h尿蛋白定量均下降,且研究组低于对照组(P<0.05)。两组患者治疗3个月后血钙水平升高,血磷水平降低(P<0.05);研究组治疗3个月后血磷水平低于对照组,血钙水平高于对照组(P<0.05)。两组患者治疗3个月后血清白介素-6(IL-6)、超敏C反应蛋白(hs-CRP)、肿瘤坏死因子-α(TNF-α)水平均降低,且研究组低于对照组(P<0.05)。两组均未见明显不良反应。结论:骨化三醇联合常规治疗可有效改善CKD患者肾功能,提高血钙水平,降低炎性因子、血磷水平,且用药安全性较好,具有一定的临床应用价值。     

子宫肌瘤动脉栓塞术改善子宫肌瘤患者预后与生活质量研究

目的:评估子宫肌瘤动脉栓塞术(UAE)改善子宫肌瘤患者预后与生活质量。方法:选取在我院介入科住院治疗的400例子宫肌瘤患者,记录患者的再干预率和出血有关的临床症状。将症状持续、恶化、症状复发和再干预定义为治疗失败(TF)。使用Kaplan-Meier分析计算成功治疗的累积率。运用Cox回归分析计算临床或形态学预测因子。评估患者生活质量和更年期的变化情况。结果:400例患者中,328例患者(82.0%)完成随访。共有54例TF,对其中46例进行了再干预治疗。Kaplan-Meier分析表明,5年后TF累积率为23.3%。Cox回归分析表明,与45岁以上女性相比,40岁以下女性更易发生TF(OR=2.29,95%CI:1.02-5.19,P=0.048)。非TF患者治疗后疾病相关生活质量显著改善(P0.001)。274例非TF患者中,有62(22.6%)例停经平均年龄为52岁。结论:UAE可以对83.5%的子宫肌瘤患者相关的症状予以长期控制,并使其生活正常化。与接近绝经期妇女相比,TF在年轻女性中的发生率更高。     

Calcium and magnesium levels in isolated cardiac mitochondria from mice injected with isoproterenol

Summary Calcium (Ca) and Magnesium (Mg) are determined by atomic absorption flame spectrometry in isolated cardiac mitochondria from mice receiving subcutaneous injections of DL-isoproterenol HC1 (ISO), and in mitochondria of untreated controls. In the controls, mitochondria were isolated in the presence or absence of ruthenium red. On the absence of ruthenium red in the isolation medium, mitochondrial Ca levels increase by about 300%, while levels of Mg remain unchanged. Focal myocardial necrosis following a single ISO-injection is shown by electron microscopy. Ca and Mg levels are largely unaffected by a single dose of ISO until 24 h after the injection. A slight increase in Ca occurs in the 48 h samples. When multiple injections of ISO are given every 12th hour for 48 h, 72 h and 96 h, respectively, endogenous Ca and Mg increase significantly. It is suggested that this increase might be associated with ISO-induced cardiac hypertrophy rather than with the pharmacological effects of ISO per se.This work was supported by grants from The Norwegian Council on Cardiovascular Disease and from The Norwegian Research Council for Science and the Humanities