203Hg-Neohydrinによる腎scintigram及び腎摂取率の研究第III篇203Hg腎摂取率について

Abstract

1) Differential measurement of the renal uptake of 203H gb y means of external scintillation counting method using 2, 3Hg-Neohydrin was described. It is necessary to measure the depth of the kidney from the body surface and to use a body phantom so as to count the activities of isotope at the site of the kidney and in the administered reagent at the identical geometrical conditions. A wider collimater-skin distance is desirable to lessen influence of error which arise in a circumstance that the depth of the kidney is estimated experimentally. 2) On 14 persons with normol kidney and 55 patients with various kidney diseases, the renal uptake rate test of 203Hg following administration of 50pc of 203Hg-Neohydrin, the differential renal clearance test and the differential PSP test were performed. On a small group of those subjects, the profile scanning and measurements of blood retention rate and urinary excretion rate were carried out to determine the distribution of isotope. 3) The renal uptake curve of normal kidney was found to have a rapid increase immediately after injection of the reagent followed by a slow slope of increase, the peak around 2 and a half hours and a slow slope of decrease. The uptake rates at 2.5 hours after injection (U2.5) were found to be mean of 25.8%, with standard deviation of 1.97, standard error of 0.55 and coefficient of variation of 7.6% for right kidney and 23.8%, 1.66, 0.46 and 7.0% respectively for the left kidney. 4) A distribution in the whole body and accumulations in the kidney and the liver of the isotope were clarified with profile scanning. 5) The isotope distribution in th e body was determined at different times following injection in circulating blood, kidney, urine and other tissues to determine the transfering situations between these organs. The 50% and 70% urinary excretion rates were observed at 7 and 14 hours respectively following injection. 6) The uptake curve or U2.5 showe d no specific patterns but lowering of uptake in response to degree of renal disturbances in various kidney diseases. In patients with single kidney, in which no pathological process is take place, the mean of U2.5 was 30% which was higher than that of seen in one side of normal both kidneys. 7) In all of 8 cases of renal hypertension, a low upt a k e on U2.5 was demonstrated in the affected side. In particularlly, the affected side was able to be decided on the uptake curve even in case where the renal scintigram failed to show any visuable difference between both kidneys. This lead us to recognize a usefullness of the method as quantitative expression of renal scintigram. 8) A relatively prop e r correlation was found between the U2.5 and simple PAH diferential renal clearance (RPF) with a coefficient of correlation being 0.53. 9) A tendency of positive correlation was shown between the U 2.5 and the 15 min. value of differential PSP test. 10) Review and discuss ion were made on literatures about the mercury diuretics on its metabolism, site and mechamism of action and distribution in the kidney. The renal uptake rate of 203Hg-Neohydrin indicates directly the activity of SH enzymes of the kidney and is supposed to show the tubular function with a relation of its reabsorption of electrolites. 11) Necessities of further studies were pointed out on the methodology of 203Hg renal uptake rate and factors which concerned to metabolism of Neohydrin. 12) It is supposed that the 203Hg renal uptake rate i s not a specific differential diagnostic method for various kidney diseases but is usefull for examination of differential renal functions on its simplicit yand reliability. Greater advantages are succesfully obtained than 131I labelled isotope renogram because of the fact that not only unilateral but also bilateral disturbance is detected quantitatively.