Circadian rhythms and the effects of water restriction and water loading on daily urinary excretion of heavy metals and organic substances, and activities of enzyme in erythrocyte for 'healthy' men in relation to renal excretory mechanism : Fundamental st

本文研究了10种重金属、4种有机物和红细胞酶活性的昼夜节律及尿量对尿中10种重金属、4种有机物和红细胞酶活性的影响，以及它们与血浆、红细胞浓度和尿肌酐排泄的关系。19名健康男性(志愿者)在自由、限水和水负荷条件下进行了为期6天(每种条件2天)的检查。尿液物质的昼夜节律与尿量(UV)、肌酐排泄节律(CN排泄节律)和每种物质的可过滤血浆浓度(FPC)有关。镉(Cd)、锰(Mn)、锌(Zn)和马尿酸(HA)的排泄节律依赖于所有受试者的CN排泄节律，而铅(Pb)、铬(Cr)、铜(Cu)、砷(As)、锡(Sn)、β-氨基乙酰丙酸(Ala)和共价卟啉(Cp)的排泄节律与FPC可以估计的组别的UV和CN排泄节律显著相关。结论：Cd、Mn、Zn和HA排泄的昼夜节律主要由肾小球滤过节律引起，而Ph、Cr、Cu、As、Sn、Ala和Cp的排泄节律受复杂的肾脏排泄机制和血浆中这些物质水平的影响。在限水条件下，尿中除汞外的所有重金属和有机物的排泄量以及肌酐排泄量均显著减少。提示肾小球滤过是决定锌、锰、镉、透明质酸排泄机制的主要因素，复杂的排泄机制影响除汞外的其他重金属和有机物。红细胞中的β-氨基乙酰丙酸脱水酶和嘧啶5‘-核苷酸酶的活性在6天内没有差异，因此这些活性不受体内水合作用的影响。

Circadian rhythms and the effects of urinary volume on daily urinary excretion of ten heavy metals, four organic substances and enzyme activities in erythrocyte were examined in relation to the changes in their plasma and erythrocyte concentrations and urinary creatinine excretion. The examination was conducted under the free, water-restrictive and waterloading conditions for six days(two days for each condition)in 19 healthy men(volunteers). Circadian rhythms of those urinary substances were related to urine volume(UV), eircadian rhythm of creatinine excretion(Cn excretion rhythm)and 'filterable' plasma concentration(FPc)of each substance. Cireadian rhythms of cadmium(Cd), manganese(Mn), zinc(Zn)and hippuric acid(HA)excretion depend on the Cn excretion rhythm for all subjects ; On the other hand, the rhythms in the lead(Pb), chromium(Cr), copper(Cu), arsenic(As), tin(Sn), delta-aminolevulinic acid(ALA)and coproporphyrin(CP)excretion were significantly related to both UV and Cn excretion rhythm for the group which FPc could be estimated. It is concluded that circadian rhythms in the Cd, Mn, Zn and HA excretion mainly result from the rhythm of glomerular filtration ; and the Pb, Cr, Cu, As, Sn, ALA and CP rhythms are affected by complex renal excretory mechanisms as well as plasma levels of the substances. Urinary excretion of all heavy metals and organic substances except mercury, together with creatinine excretion, significantly decreased under the water restrictive condition. It is suggested that glomerular filtration is the major factor determining renal excretory mechanisms of Zn, Mn, Cd, HA, and the complex renal excretory mechanisms effect the other heavy metals and organic substances except mercury. The activity of delta-aminolevulinic acid dehydratase and pyrimidine 5'-nucleotidase as the enzymes in erythrocyte did not differ for the six days, so these activities have not affected by body hydration.