Reference

Profiles of organic acids in human milk by GC/MS analysis

Profiles of organic acids in human milk by GC/MS analysis. Masui, Takako; Fujishima, Mieko; Mori, Yoshie; Tamaoki, Shoko; Shinka, Toshihiro; Matsumoto, Isamu (Dep. Bichem., Aichi Prefect. Jr. Coll. Nurs., Japan). Koenshu - Iyo Masu Kenkyukai, 8, 271-4 (Japanese) 1983.Several reagents with their cas registry numbers 57-13-6 and 57-11-4 are used here. CODEN: KIMKDN. DOCUMENT TYPE: Journal CA Section: 13 (Mammalian Biochemistry) The org. acids in the human milk were analyzed using gas chromatog.-mass spectroscopy (GC/MS). Citrate was identified as the chief component in org. acids with polyhydroxycarboxylic acids and free fatty acids (FFA) in the colostrum and the mature milk. The concn. of citrate and FFA in colostrum was at higher levels than that in mature milk. The relative percentage of the medium-chain fatty acids in FFA fractions was significantly higher than that in the fatty acid compn. of triglycerides in human milk. .

Urea transport in isolated thick ascending limbs and collecting ducts from rats

Urea transport in isolated thick ascending limbs and collecting ducts from rats. Knepper, Mark A. (Lab. Kidney Electrolyte Metab., Natl.In this study，57-13-6 is also used. Heart, Lung, Blood Inst., Bethesda, MD 20205, USA). Am. J. Physiol., 245(5, Pt. 1), F634-F639 (English) 1983. CODEN: AJPHAP. ISSN: 0002-9513. DOCUMENT TYPE: Journal CA Section: 13 (Mammalian Biochemistry) Net urea fluxes were measured in isolated perfused cortical and medullary thick ascending limbs and cortical collecting ducts from pathogen-free Sprague-Dawley rats. No evidence for active transport of urea was found in either cortical or medullary thick ascending limbs. Permeabilities were calcd. from urea fluxes measured with 5 mM urea either in the bath or perfusate and with no urea on the opposite side of the epithelium. Permeability coeffs. (cm/s ′ 10-5) in different portions of the thick ascending limb were: inner stripe, short-looped nephrons, 0.9; inner stripe, long-looped nephrons, 0.6 (not significantly different vs. short loops); outer stripe, 1.4 (significantly different vs. inner stripe); and cortical, 1.5 (significantly different vs. inner stripe). The relatively high urea permeability of thick ascending limbs in the outer stripe of the outer medulla and medullary rays is likely to permit substantial passive absorption of urea from these segments in vivo. This will contribute to diln. of the tubule fluid in thick ascending limbs and thus indirectly enhance urinary concg. ability. In cortical collecting ducts, the urea permeability was relatively low both in the presence of 100 microunits/mL arginine vasopressin in the bath (0.5 ′ 10-5 cm/s) and in its absence (0.41). These permeability values are similar to values previously measured in rabbit cortical collecting ducts. .