UPTAKE OF INTRAVENOUSLY ADMINISTERED PROGESTERONE, PREGNANEDIONE AND PREGNANOLONE BY THE RAT BRAIN

1968 ◽  
Vol 57 (3) ◽  
pp. 395-404 ◽  
Author(s):  
K. H. Raisinghani ◽  
R. I. Dorfman ◽  
E. Forchielli ◽  
L. Gyermek ◽  
G. Genther

ABSTRACT A method has been developed for the detection, isolation and quantitation of progesterone, pregnanolone and pregnanedione in brain tissue of rats receiving pharmacological hypnotic doses of these three substances. Prior to extraction radioactive tracers were added to brain tissue obtained from animals receiving these agents and the brain tissue extracts were purified by paper and thin layer chromatography. The material administered as well as some of the major metabolites were quantitated by gas liquid chromatography, and corrections for losses throughout the entire procedure and up to injection into GLC were based on recovery of added radioactive markers. The possible significance of the conversion of progesterone into hypnotically more potent metabolites is discussed.

1970 ◽  
Vol 63 (3) ◽  
pp. 512-518 ◽  
Author(s):  
Leon J. Sholiton ◽  
Ila L. Hall ◽  
Emile E. Werk

ABSTRACT Rat and bovine brain homogenates have been incubated with [4-14C] testosterone under standard conditions. With use of paper chromatography, the extracted metabolites were noted to fall into less polar, iso-polar, and more polar fractions. The components of the iso-polar fraction were separated after acetylation by thin-layer chromatography and the major end-product identified by gas-liquid chromatography and recrystallization to constant specific activity. Rat brain forms a major iso-polar metabolite, allo-tetrahydrotestosterone, and a small amount of tetrahydrotestosterone. Neither of these could be detected in the bovine brain incubates.


Author(s):  
A.A. Parshutina ◽  
◽  
A.A. Solovyova ◽  
L.P. Satyukova ◽  
E.G. Shubina ◽  
...  

The article shows the importance of the study of feed for broiler chickens on the content of organochlorine pesticides. These substances in significant concentrations can disrupt the development of birds and cause mass poisoning. The study of formula feed for broiler chickens «prestart» and «start» by two methodswas conducted: a certified method for the determination of organochlorine pesticides in feed and formula feed (thin layer chromatography) and a method for detecting pesticides not certified for feed (gas-liquid chromatography with mass spectrometer detector). During the experiment, the presence of organochlorine pesticides in several formulafeed samples was revealed.


1967 ◽  
Vol 50 (3) ◽  
pp. 615-623
Author(s):  
Kenneth T Hartman

Abstract Gas-liquid chromatography (GLC) following conventional isolation procedures has been used to clean up pesticide residues for confirmation by thin layer chromatography (TLC). This procedure is more rapid and efficient than present cleanup procedures and permits the determination of pesticide residues that do not survive these rigorous acid or alkali treatments. The method also permits TLC confirmation of pesticide residues that have similar Rf values but different GLC retention times. Recoveries ranged from 85 to 105% for 25 of 28 pesticides tested


1977 ◽  
Vol 60 (5) ◽  
pp. 1105-1110 ◽  
Author(s):  
John H Onley ◽  
Laura Giuffrida ◽  
N Fred Ives ◽  
Randall R Watts ◽  
Robert W Storherr

Abstract The Onley-Yip procedure for determining ethylenethiourea (ETU) in milk and crops was modified to reduce interferences by the ethylenebisdithiocarbamates (EBDCs). A 20 g cropmethanol extract is cleaned up by adsorbing the sample onto Gas-Chrom S, desorbing ETU, and eluting ETU from aluminum oxide with chloroform containing ethanol. ETU is converted to the S-butyl derivative for gas-liquid chromatography (GLC) and flame photometric detection (sulfur mode). For liquid chromatography (LC), ETU is cleaned up on another aluminum oxide column and injected directly. LC and GLC results are confirmed by thin layer chromatography. A cooking procedure based on conversion of EBDCs to ETU is included for surveying crops for possible EBDC content. Recoveries from 8 crops and milk fortified at 0.05 ppm ETU ranged from 73 to 100%.


1969 ◽  
Vol 52 (4) ◽  
pp. 774-778
Author(s):  
C W Thorpe ◽  
Linda Pohland ◽  
D Firestone

Abstract A inethod is described for analysis of sterols by thin layer chromatography-gas liquid chromatography (TLC-GLC). Sterols are isolated from other components of unsaponifiable matter by preparative TLC. The sterols are quantitatively removed from the TLC plate, extracted from the silica gel, and analyzed by GLC. This method has been used to detect low levels (2–3%) of animal fat in vegetable oil by measuring the cholesterol content of the animal fatvegetable oil admixtures.


1969 ◽  
Vol 60 (2) ◽  
pp. 265-275 ◽  
Author(s):  
D. B. Gower ◽  
Margaret I. Stern

ABSTRACT The level of 3α-hydroxy-5α-androst-16-ene (Δ16-androstenol) excreted as glucuronide in the urine of a woman with virilising adrenal carcinoma was measured by gas-liquid chromatography (GLC) of the free steroid and its chloromethyl dimethyl silyl (CMDS) ether and found to be 1.46 mg/day. On the basis of thin-layer chromatography (TLC) and GLC of free steroid and derivatives, Δ16-androstenol has also been tentatively identified in the urinary sulphate fraction and in peripheral plasma. The values were approx. 0.6 mg/d and 2.8 μg/100 ml respectively. After operation, the amount of urinary Δ16-androstenol (as glucuronide) fell to a low level; none was detected in plasma or in urine (as sulphate). Levels of other steroids in the urine and plasma were consistent with the clinical diagnosis of virilising adrenal carcinoma. After operation, the excretion of most of these steroids had reverted to values which were normal or lower. In vitro, the cancerous adrenal tissue metabolised 4-14C-pregnenolone to 3β-hydroxy-androsta-5,16-diene (0.2 %) and 4-14C-progesterone to a small quantity (< 0.03 %) of androsta-4,16-dien-3-one. No androst-16-enes were formed from radioactive dehydroepiandrosterone (DHA) or testosterone. The formation of other labelled metabolites confirmed studies by earlier workers.


Sign in / Sign up

Export Citation Format

Share Document