Two commercially available (Abbott Labs.) radioimmunoassays for determination of conjugated cholic acid and sulfoglycolithocholic acid in serum have been modified for bile acid measurements in alcoholic tissue extracts, bile, and urine. The specificity of both radioimmunoassays has been determined with regard to 27 free and conjugated bile acids. After filtration, bile acids can be measured in urine and bile without prior extraction. Tissue is homogenized and the bile acids are extracted into methanol. Urinary excretion by 64 healthy humans was 2.09 (SD 1.09) mumol of conjugated cholic acid and 8.44 (SD 8.03) mumol of sulfated glycolithocholic acid per 24 h. In liver from 10 patients with various noncholestatic liver disease, the mean concentration of conjugated cholic acid was 32.4 (SD 15.9) nmol/g wet weight. In the liver of 27 male Wistar rats, the concentration of conjugated cholic acid was 41.3 (SD 11.7) nmol/g of tissue, of sulfoglycolithocholic acid 5.1 (SD 2.3) nmol/g of tissue.
Zahlreiche Verfahren zur NH 4 +-Bestimmung im Blut und im Urin sind bisher angegeben und von anderer Seite auch wieder kritisiert worden. Die seit einigen Jahren für die Bestimmung von Ammoniak im Blut bekannte enzymatische Methode von KIRSTEN et al. ([1963], Biochem. Z. 3*7, 312-319), SCHMIDT & SCHWARZ ([1966]
The determination of ammonia in the urine of premature and full-term newborns: Comparison of the formol titrationand the en^ymic NH^~ determination Numerous methods for the determination of NH 4 + in blood and urine have been described and subsequently criticized by other workers. The specificity and reproducibility of the enzymatic procedure for the determination of ammonia in blood according to KIRSTEN et al. ([1963], Biochem. Z. 337, 312-319), SCHMIDT & SCHWÄRS ([1966], Klin. Wochenschr. 44, 591-592) and MÜTING et al. ([1970], Deut. Med. Wochenschr. 95, 1390-1396) was tested on urines by comparing it with the very simple formol titration method. The latter method is unsuitable in spite of its high precision, because of the marked influence exerted by amino acids. On the other hand the enzymatic NH 4 + determination is applicable to the urines of premature and full-term newborns particularly because of the relatively low NH 4 + level and the relatively high amino acid concentration. Its precision is equal to the formol titration method, but in addition it is specific and posesses a high sensitivity.
I' T Gerson, BB. Shorelandu. G. G. Duncklty,Theeffect ofbeta-silosterol on the metabolism of cholesterol and lipids in rats on a diet low in fat, Biochem. J. 92,385 [ I!)(i4(. B. J. Kudchodkar, L. Horlick u. H. S. Sodhi,Effects of plant sterols on cholesterol metabolism in man, Atherosclerosis 23,230 [ I'J7.51. '' B R . Raicht, B. I. Cohen, S. Sheferu. E. H. Mosbacher,Sterol balance studies in the rat. Effects of dietary cholesterol and p-sitosterol on sterol balance and rate-limiting enzymes of sterol metabolism, Biochem. Biophys. Acta 388,374 [ 1!)75]. 'I' S. M. Glundy u. H. Y J . Mok, Effects of low dose phytosterols on cholesterol absorption in man, in: H. Greten (ed.), Lipoprotein Metabolism, Springer-Verlag, Berlin, 112 (1976)..
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.