On the electrophoretic enzymogram of serum lactate dehydrogenase isoenzymes, an extra band was found cathodaly to LDH-5 (M4). This extra band was identified as alcohol dehydrogenase (ADH) activity by the following evidence; the extra band was still observed even when lactate was omitted in the LDH reaction system, its electrophoretic mobility was corresponded to that of humau liver ADH isoenzyme, the activity of this band was increased by adding of ethanol to the reaction mixture of LDH isoenzyme and was inhibited by Pyrazole. The mechanism responsible for the appearance of ADH activity is that alcohols in the specimen are coupled with NAD-PMS-tetrazolium salt system which is involved in the LDH reaction mixture, to from formazan. The ADH band was found in the serum of patients with severe liver cell necrosis due to acute hepatitis, acute heart failure and bile duct stone.
Rhizopus C-lipase displayed appreciable triglyceride-hydrolyzing activity upon isolated human plasma lipoproteins after treatment with a phospholipid. Treatment of the lipase with phosphatidylcholine or cardiolipin was most effective in enhancing the activity on these substrates. The treated enzyme acted equally well on any of three lipoproteins, chylomicron, very low density lipoprotein (pre-β) and low density lipoprotein (β).
Treatment of 5α-pregnane-3α, 20-αdiol disulfate (II) with 3 N hydrochloric acid under heating gave a corresponding hydrolyzate, which was shown to contain various degradation products by gas chromatography. The structural assignment of these materials was investigated by gas chromatography-mass spectrometry and these were identified as: 17α-ethyl-17β-methyl-5α-androst-13-en-3α-ol (III), two isomeric compounds (IV and V) of 5α-pregn-17 (20)-en-3 α-ol, and 5α-pregnane-3α, 20β-diol (VI). The yield of the intact aglycone (I) obtained was less than 20% of the total steroid produced. The speculation of the structures on other minor products is also described and the mechanism on the formation of degradation products is briefly discussed.
This report is concerned with the colorimetric assay method of carboxypeptidase A activity in serum using carbonaphthoxy-L-phenylalanine (CNPA) as a substrate and the hydrolytic activity of CNPA in this reaction system. 1) No effect was observed with the addition of DFP, cyanide, trypsin or epsilon aminocaproic acid. 2) Activity was inhibited by dialysis against o-phenenthroline solution, and recovered with the addition of Zn+ + ions. 3) Further addition of the CPase A substrates (different from CNPA) inhibited this reaction, whereas the presence of CPase B substrates showed no effect. 4) In organs of humans and dogs, the pancreas was found as the only organ which was rich in CPase A activity, while traces of activity were observed in the kidneys. 5) The mean serum CPase A activity in 28 normal subjects was 289.2±3.8 units (range 272.0-312.4 units). 6) In almost all subjects with pancreatic cancer, and in some subjects with liver cirrhosis, chronic pancreatitis, diabetes mellitus, cholelithiasis, or chronic glomerulonehritis, a low level of serum CPase A activity was observed. 7) The serum CPase A level in a patient who had undergone a total pancreatectomy dropped rapidly, and only negligible activity was found 3 weeks after the operation, while serum levels of total protein, cholinesterase and amylase showed minor changes during the same clinical course. 8) It was observed that amylase activity and CPase A activity in serum changed inversely in experimental pancreatitis. Moreover, this amylase activity and CPase A activity varied in inverse proportions to each other.
A Simple analytical method for kallikrein (E. C. 3, 4, 21, 8) by electrophoresis on a cellulose acetate membrane was established. Detection of the components which could hydrolyze BAEE, such as kallikrein, trypsin, etc., was carried out on the membrane by a reaction with BAEE and then by a modified formazan stain. Various preparations of hog pancreatic kallikrein of different purities were used. Kallikrein migrated towards the anode and there were two or more active components in these kallikrein preparations. Clear separation from trypsin was possible by this system. The procedures are simple and this method is suitable for the detection of kallikrein even in a crude preparation.
A method for determination of Plasma dehydroepiandrosterone sulfate using 3 β-hydroxysteroid oxidase is described. The method includes lipides removal and protein precipitation by adding a mixture of chloroform and methanol (2: 1, v/v), and solvolysis after extraction with ethylacetate under pH 1 with NaCl saturation, and fluorometric determination using 3 β-hydroxy-steroid oxidase, peroxidase and homovanillic acid by the method of G. G. Guilbault et al. Precision of this method was 5.7% of CV and recovery was 98.2%. These results were satisfactory for determination of plasma dehydroepiandrosterone sulfate in clinical test. An advantage of the method is that the determination can be performed without use of radioactive compound.
A new simple and rapid fluorometric micromethod for determining serum malondialdehyde is described. The method is less complicated and more sensitive than the Yagi method which is widely employed in clinical laboratories, and is more specific than the Naito method due to a considerable elimination of an interfering effect of sialic acid. Relationship between the total cholesterol and the malondialdehyde levels in serum is studied.