Plasma levels, urinary excretions and renal clearances of free amino acids were measured in 11 normal adults, 3 normal olds and 57 patients with renal and metabolic disorders using paper or gas chromatographical analysis. Hypoaminoacidemia was observed in old subjects. Hyperaminoacidemia was found in patients with diabetes mellitus (valine, leucine and isoleucine), hyperparathyroidism (almost all amino acids) and gout (glutamic acid, glutamine, glycine and tyrosine). In cases with glomerulonephritis or nephrotic syndorome whose renal function was moderately disordered, renal clearances of glutamic ocid, threonine, serine, lysine or throsine were elevated, while in cases with uremia, renal clearances of almost all amino acids were conversely decreased. Increased renal clearances of amino acids were seen in cases with renal tubular acidosis (glutamic acid, glutamine and lysine) and Prader-Willi syndorome (glutamic acid and alanine). The patients with Fanconi syndorome, Willson's disease (almost all amino acids) and cystinuria (cystine, lysine, arginine and ornitine) showed extremely high values of renal amino acid clearance. In order to elucidate the transport mechanism of neutral amino acid in tubular cells, amino acid solution (alanine, threonine, serine, proline and glycine) was each injected intravenously to normal subjects and patients with renal disease, and plasma levels and renal clearances of amino acids were compared before and after infusion. The amount of amino acid infused was 0.65 mmole/kg of each according to Scriver's method. The ratio of elevation of both plasma level and renal clearance of infused amino acid in these experiments were generally higher in cases with glomerulonephritis and nephrotic syndrome than in normal adults; this is probably due to differences of glomerular filtration rate and utilization of injected amino acid between two groups. Proline and glycine were found to compete each other in the transport system of renal tubular cells, but alanine, threonine and serine were not; this may reflect that latter amino acids have greater tubular maximal reabsorption rates.

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Renal Micropuncture study of the Wistar strain rat was performed and the following results were obtained.Results; (1) In the proximal tubule of the control rat Kidney, [TF/P]inulin was 1.86+0.64, [TF/P]osm 0.97±0.05, [TF/P]Na 0.99+0.03, and [TF/P]K 1.02+0.07, respectively. There were no significant change in [TF/P] values of the above menthioned solutes under the control, diuretic and antidiuretic conditions. (2) In the distal tubule, [TF/P]osm, Na were lower under the antidiuretic condition, whereas [TF/P]Na was only slightly depressed under the diuretic condition. (3) In the samples of ureter fluids, [TF/P]inulin, osm, Na, K were lowered under the diuretic condition, , whereas [TF/P] inuiln, osm, K were elevated but [TF/P] Na was depressed under the antidiuretic condition. (4) Pitfalls of Micropuncture Study (i) Negative pressure of sampling fluids should be avoided, since fluid movenent backwards from distal site made significant errors. (ii) In order to avoid contamination of inulin estimation, accurate sampling into the microcuvette and complete removal of air in cuvette were needed. (iii) Amount of samples should be same as far as possible for the osmorality determination.

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In the previous report, we described on suppression of angiotensinase (ATase) activity, and some ;properties of renin. The present paper concerns to the purification of angiotensin (AT) produced. We tried to extract and to condensate AT in plasma with several organic solvents, ion exchange chromatography or evaporation in reduced pressure. Then, we made it a rule to use the combination of n-butanol and water extraction, and ion exchange chromatography. The recovery of added AT was 70 percent (range from 55 to 85%) by this method. Combining this method with the previous report, we decided a method for determination of plasma renin activity. AT concentration in the assaying solution is about 3 fold larger than before the extraction treatment. But this condensation rate is still not enough, as well as the recovery of AT. Neverthealess, we consider that our method is clinically applicable.

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The ultrastructural changes in the glomerulus of 28 biopsy specimens taken from 26 patients with subchronic glomerulonephritis (GN) were studied by electron microscopy. The relationship between these morphologic changes and the clinical findings, especially preceding infections and hematuria, or the immunofluorescent studies was also studied. Subchronic GN is defined by Kinoshita as a distinct entity of chronic but nonprogressive form of GN without functional insufficiency. It is divided into four types (Type I-IV) according to the severity of the glomerular lesions. The specimens, fixed in glutaraldehyde and osmium tetroxide, or osmium tetroxide alone and embed-ded in epon epoxy resin, were sectioned with glass knives on a Porter-Blum microtome. The sections were stained with uranium acetate and lead tartrate and examined with Hitachi HS-7 electron microscope. The results were as follows, (1) The common electron microscopic finding in each type of subchronic GN was the increase of mesangial matrix. The mesangial matrix increased slightly as spotty or scattered form in Type I. In. Type II to IV it increased more and became more dense and lumpy. Most of the cases with Type 11 to if revealed the increase in mesangial cells as well as focal changes of the basement membrane, such as thinning, winding, splitting or disruption. The electron dense, well defined deposits in the mesangiall area, which was assumed as immune deposits, were found in 18 out of 28 specimens. No deposit was. seen in the subepithelial or subendothelial side of the peripheral capillary basement membrane. It sug-gests that the immunologic reaction would probably occur in the mesangial area. (2) There was no paticular relationship between the deposit and microscopic hematuria, but four cases without microscopic hematuria had no deposit. (3) Seventeen cases had chronic tonsillitis at the time of admission, 13 of which showed the deposit: in the mesangium. (4) Three of 4 cases without the deposit revealed the presence of IgG and β₁C-globulin in the mesan-gium by fluorescent antibody technique, but neither IgA nor IgM was demonstrated. IgA and IgM were usually found in the mesangium of the cases with the deposit. There seems to be close relationship 4 between the presence of IgA or IgM and the deposit. (5) It is assumed that a few different immunologic mechanismus may contribute to the pathogenesis of subchronic GN.

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Daily injections of 20 mg. prednisolone to normal rabbits for six weeks produced exudative lesions in renal glomeruli. The lesions were essentially those of thrombocapillaropathy by lightmicroscopic, immunofluorescence and electronmicroscopic observation. Changes in blood coagulation properties, blood corpuscles, plasma lipids, fasting blood sugars, plasma total proteins, serum potassiums, BUN, serum transaminases, body-weights and urinary findings produced by administrations of prednisolone were investigated serially. Platelet aggregation and plasma recalcification time were markedly reduced, and kaolin activated P. T. T, was slightly shortened. Increase of thrombotest activity and activation or supression of fibrinolysis were confirmed. These changes, representing hypercoagulable states were exaggerated from two to three weeks after starting injections. Plasma fibrinogen contents and blood platelets gradually decreased. Platelet aggregation time as well as plasma recalcification time were inversly proportional to incidences of the lesions respectively. Blood corpuscles decreased. Levels of total cholesterol decreased, but those of free fatty acids and phospholipids remained almost unchanged. On the other hand, triglyceride levels significantly increased, directly proportional to incidences of the lesions. Levels of blood sugars elevated only at 6 th week. Other chemical blood components and body-weights did not show any significant changes. Proteinuria, often with hematuria, and glycosuria appeared transiently during the experiments. Further, effects of the anticoagulant drug on this steroidnephropathy were investigated using warfarin and following results were obtained. Occurrences of the lesions were markedly inhibited in the good-controlled group, but unchanged in the fair-controlled group as compared with those of the prednisolone-alone-group. In the poor-controlled group, however, occurrences of the lesions were significantly increased. From these observations, it was concluded as follows : 1) Thrombocapillaropathy was an essential process in steroidnephropathy. 2) The development of the lesion was dependent on hypercoagulable states produced by administrations of glucocorticoids, and hyperlipemia also participated in the development and modification of these lesions. Definition of steroidnephropathy was discussed finally.

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