Mineo Yamasaki

Differential expression of nitric oxide synthase isoforms in form-deprived chick eyes

PURPOSE To clarify whether nitric oxide synthase (NOS) is involved in development of myopia, we examined the influence of form deprivation on the expressions of NOS isoform mRNA. METHODS NOS isoform cDNAs were amplified from total RNA extracted from control and 7-day-form-deprived chick retina-RPE (retinal pigment epithelium)-choroid, using competitive RT-PCR (reverse-transcription polymerase chain reaction). Each NOS isoform protein was also analyzed by Western blotting and immunohistochemistry. RESULT Expression of inducible NOS (iNOS) mRNA was highest in the control chick retina-RPE-choroid, followed by the expression of brain NOS (bNOS) mRNA. Expression of endothelial NOS (eNOS) mRNA was faint. The iNOS protein level, however, was only slightly higher than the levels of the bNOS and eNOS proteins and was found mainly in the outer part of the photoreceptor layer and inner and outer parts of RPE and choroid. bNOS alone was found in the outer nuclear layer. Although form deprivation reduced the iNOS and bNOS mRNA expressions, only the iNOS protein showed significant reduction. CONCLUSION All three NOS isoforms were expressed in chick retina-RPE-choroid. Predominant expression of iNOS, instead of bNOS and eNOS, suggested the existence of ocular tissue-specific regulation of the iNOS gene. In addition to differences in expression level, bNOS displayed regional differential expression. Moreover, only iNOS was reduced in response to form deprivation. It is suggested that NOS isoforms may be differentially involved in the mechanisms regulating the posterior eye tissues, including myopic eye growth.

Element content of human umbilical artery and vein in umbilical cord.

To elucidate the element content of newborn blood vessels, umbilical arteries and veins in human umbilical cords, which had the advantage of easy sampling, were examined by ICP-AES. Umbilical cords were removed after birth. Mothers’ ages ranged from 26 to 35 yr. It was found that the content of sulfur was the highest in both umbilical arteries and veins, being higher than the content of calcium and phosphorus. With respect of the content of sulfur, calcium, and magnesium, there were significant differences between the arteries and veins.

High accumulation of calcium in human uterine artery with aging.

To elucidate compositional changes of the rami of the internal iliac artery with aging, the authors investigated age-related changes of the calcium content in the uterine, internal pudendal, umbilical, and obturator arteries by inductively coupled plasma-atomic emission spectrometry. After an ordinary dissection was finished, the uterine, internal pudendal, umbilical, and obturator arteries were resected from 10 female subjects, and the internal pudendal, umbilical, and obturator arteries were resected from 10 male subjects. The female subjects ranged in age from 52 to 96 yr, and the male subjects ranged in age from 63 to 88 yr. The calcium content in the uterine artery began to increase in the seventies and increased markedly in the nineties. In the internal pudendal artery, the calcium content hardly increased up to the eighties and increased significantly in the nineties. In contrast, the calcium content did not change in both the umbilical and obturator arteries with advancing age. It was found that the average content of calcium was the highest in the uterine artery and decreased in the order internal pudendal, umbilical, and obturator arteries. The average content of calcium in the uterine arteries corresponded to 46-fold the amount of the womens obturartor arteries, in which it was the lowest. In the cases of men, the average content of calcium was higher in the order of the internal pudendal, umbilical, and obturator arteries. Regarding the average content of calcium, the order internal pudendal, umbilical, and obturator arteries of the men was consistent with that of the women.

Increases of calcium and magnesium and decreases of phosphorus and iron with aging in human uterine tubes.

To elucidate compositional changes of the uterine tube by aging, the authors studied age-related changes of elements in human uterine tubes by inductively coupled plasma-atomic emission spectrometry. The uterine tubes were resected postmortem or surgically removed from patients with uterine myoma. It was found that the contents of calcium and magnesium increased progressively with aging in uterine tubes, whereas the contents of phosphorus and iron decreased gradually with aging. The sulfur content of uterine tubes remained constant and independent of aging.Regarding relationships between elements, significant relationships were found between calcium and magnesium contents, between phosphorus and iron contents, between phosphorus and sulfur contents, and between phosphorus and sodium contents in human uterine tubes.

PP094. A comparison of gestational changes in urinary excretion of magnesium with those of calcium.

INTRODUCTION Magnesium is one of the essential minerals required in various cellular functions. Some investigators have postulated that some aspects of pathophysiology in preeclampsia could be associated with alteration in regulatory mechanisms of the mineral. However, gestational changes in absorption, excretion and blood concentration of magnesium have remained less elucidated compared with those of calcium, which is another important mineral forming a divalent cation. OBJECTIVES The purpose of this study was to clarify if urinary excretion of magnesium during pregnancy might be altered compared with those of calcium. METHODS Sixty specimens of 24h urine and 586 samples of spot urine were collected from healthy pregnant women who gave consent. Determination of the minerals were according to Orthocresol-phthalein complexone method for calcium, and xylidyl blue method for magnesium. Urinary creatinine was determined by Jaffe Method. RESULTS Daily excretions of magnesium determined with 24h samples were 60, 70, 81, 65, and 102mg in 1st, 2nd, and early 3rd trimesters, term, and postpartum 4weeks, respectively. There were no statistical differences among the values. Those of calcium were 174, 186, 139, 52, and 40mg, respectively. The values in term and in postpartum were significantly lower than those in 1st through early 3rd trimesters. The Mg/Cr ratios (mg/mg Cr) determined with spot urine samples were 0.064, 0.071, 0.066, 0.067, and 0.086, in 1st, 2nd, and early 3rd trimesters, term, and postpartum 4weeks, respectively. The value of Mg/Cr in postpartum was significantly higher than the values in pregnant period. The Ca/Cr ratios (mg/mg Cr) were 0.164, 0.163, 0.135, 0.118, and 0.090, respectively. There was a trend of decreasing pattern in changes of Ca/Cr from 2nd trimester to postpartum. CONCLUSION It is suggested that there is a mechanism of preservation of calcium in the late phase of pregnancy or puerperal period by reducing urinary excretion of the mineral. However, human pregnancy does not seem to show such a function controlling magnesium metabolism.

Age-dependent decreases of sulfur and magnesium in human round ligaments of the uterus and relationships among elements

To elucidate the compositional change of ligaments with aging, the authors investigated both age-related changes of elements and relationships among elements in the round ligaments of the uterus (round ligaments) by inductively coupled plasma-atomic emission spectrometry. The bilateral round ligaments were resected from 20 cadavers and also from the uteri removed surgically from 11 patients bearing uterine myoma or cancer. Thirty-one subjects ranged in age from 34 to 92 yr. It was found that both S and Mg decreased gradually in the round ligaments with aging, but Ca, P, Zn, Fe, and Al did not change significantly with aging. Regarding the relationships among elements, very significant direct correlations were found among the contents of Ca, P, S, and Mg in the round ligaments, whereas significant inverse correlations were found between the contents of Zn and elements, such as Ca, P, S, and Mg. It should be noted that there was an extremely significant direct correlation between Ca and P contents in the round ligaments.