STUDIES ON THE METABOLISM OF C-19 STEROIDS IN THE HUMAN FOETO-PLACENTAL UNIT

1967 ◽  
Vol 56 (2) ◽  
pp. 203-220 ◽  
Author(s):  
G. Benagiano ◽  
F. A. Kincl ◽  
F. Zielske ◽  
N. Wiqvist ◽  
E. Diczfalusy

ABSTRACT 3H-labelled androst-4-ene-3,17-dione and 14C-labelled testosterone were administered at laparotomy into the intact foeto-placental circulation and the principal metabolites present in the placenta and various foetal tissues were isolated and identified. Five subjects were investigated; all foetuses were females. Except in the liver, where there was a complete interconversion, in all tissues more testosterone was converted into androstenedione than vice versa. The following unconjugated (ether soluble) metabolites were isolated: 5β-androstane-3,17-dione from the liver, gastro-intestinal tract and residual foetal tissues; 3α-hydroxy-5β-androstan-17-one (liver, lungs, gastrointestinal tract, residual foetal tissues); 5β-androstane-3α,17β-diol (liver); 5α-androstane-3,17-dione (lungs, gastro-intestinal tract, residual foetal tissues); 3α-hydroxy-5α-androstan-17-one (lungs, gastro-intestinal tract, residual foetal tissues); 11β-hydroxyandrost-4-ene-3,17-dione (adrenals); oestrone (placenta and combined foetal tissues); 17β-oestradiol (placenta); oestriol (placenta). The following metabolites were isolated from the conjugated (water soluble) fraction of the liver: testosterone, 3α-hydroxy-5β-androstan-17-one, 3β-hydroxy-5β-androstan-17-one, 5β-androstane-3α,17β-diol, oestrone, 17β-oestradiol, oestriol. In addition, oestrone was isolated from the aqueous phase of the placentas, oestrone, 17β-oestradiol and oestriol from the aqueous phase of the combined foetal tissues, and 15α-hydroxy-oestradiol was detected and characterized in the extracts of placentas and livers. A high degree of enzymic stereospecificity in the reduction of the administered androstenedione and testosterone was observed in the various foetal tissues: 3α,5β-forms were predominant in the liver, with little, if any 3α,5α-forms present. In the lungs and residual foetal tissues, 3α,5α-products were predominant, whereas in the extracts of the gastrointestinal tract both types of reduction products were present in approximately equal amounts.

1973 ◽  
Vol 21 (3) ◽  
pp. 217-226
Author(s):  
B.D.E. Gaillard ◽  
A.T. van 't Klooster

One cow was provided with cannulae in the proximal duodenum and terminal ileum. Three experimental rations were offered: 1, hay 7 kg/day and concentrate 6; 2, hay 3 kg/day, paper pulp 3 and concentrate 3.7; 3, fresh grass 11 kg DM/day. Rations 2 and 2 were given twice daily and 3 was offered more frequently. Experimental periods were 5 days in experiment 1 and 7 days in 2 and 3. Samples were taken from each cannula every 2 h for 5 days. Faeces were collected in each period. Flow rate of the intestinal contents was measured with polyethylene glycol and chromium sesquioxide as markers. Carbohydrates in the feed, digesta and faeces were fractionated according to solubility into ethanol-soluble sugars, alpha -glucose polymers, fructosan, water-soluble polysaccharides other than alpha -glucose polymers and fructosan, neutral-detergent-soluble polysaccharides and neutral-detergent residue. Sugars, sialic and uronic acids were measured in the hydrolysates and the sugars were separated chromatographically.Most of the ethanol-soluble sugars and all the fructosan was digested in the rumen, reticulum, omasum and abomasum, considered collectively as the stomach. Digestion of alpha -glucose polymer occurred mainly in the stomach and only 5 to 10% was digested in the small intestine and caecum with colon. The hay and concentrate ration contained more starch than the others and a higher proportion of this was digested in the small intestine and caecum with colon (20.3 and 6.8% of the digestible starch). The water-soluble fraction was digested mostly in the stomach; on rations 1 and 3 more component carbohydrates disappeared from the small intestine than the caecum with colon. Bacterial polysaccharides were thought to be digested in the small intestine and some bacterial growth was indicated, particularly on ration 2 which contained large amounts of cellulose. Fermentation and addition of bacterial polysaccharides and mucus confused the picture of digestion of the neutral-detergent-soluble fraction, but on all 3 rations it was higher in the small intestine than in the caecum with colon. The neutral-detergent residue was mainly fermented in the stomach and the caecum with colon. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1992 ◽  
Vol 117 (4) ◽  
pp. 600-606 ◽  
Author(s):  
H. Yoshioka ◽  
K. Aoba ◽  
Y. Kashimura

The concentrations of water-soluble polyuronides in apples [Malus domestica Borkh.) and pears (Pyrus communis L.) increased, but those of EDTA- and HCl-soluble polyuronides decreased during softening. Total polyuronide content decreased slightly during softening in both fruits. Depolymerization of polyuronides was observed only in the water-soluble fraction in pear fruit during softening, concomitant with an increase in polygalacturonase (PG) activity. No detectable depolymerization was observed in any of the polyuronide fractions during softening of apple fruit nor was any PG activity detected. The polyuronide fractions extracted from pear and apple cell walls contained various amounts of methoxyl groups. Polyuronides with a high degree of methoxylation were preferentially lost from EDTA- and HCl-soluble polyuronides during softening of both fruit. The water-soluble polyuronide had a lower degree of methoxylation than those lost in the EDTA- and HCl-soluble fractions. These results suggest de-esterification of polyuronides with a high degree of methoxylation rather than the depolymerization of polyuronides in the solubilization of polyuronides during ripening of apples and pears.


2014 ◽  
Vol 91 (5) ◽  
pp. 473-481 ◽  
Author(s):  
Guiai Jiao ◽  
Xiangjin Wei ◽  
Gaoneng Shao ◽  
Lihong Xie ◽  
Zhonghua Sheng ◽  
...  

1957 ◽  
Vol 35 (4) ◽  
pp. 241-250 ◽  
Author(s):  
W. G. Martin ◽  
J. E. Vandegaer ◽  
W. H. Cook

Livetin, the major water-soluble protein of hen egg yolk, was found to contain three major components having mobilities of −6.3, −3.8, and −2.1 cm.2 sec.−1 volt−1 at pH 8, µ 0.1, and these have been designated α-, β-, and γ-livetin respectively. The α- and β-livetins were separated and purified electrophoretically after removal of γ-livetin by precipitation from 37% saturated ammonium sulphate or 20% isopropanol. The α-, β-, and mixed livetins resembled pseudoglobulins in solubility but γ-livetin was unstable and this loss of solubility has, so far, prevented its characterization. Molecular weights determined by light scattering, osmotic pressure, and Archibald sedimentation procedure yielded respectively: 8.7, 7.8, and 6.7 × 104 for α-livetin, and 4.8, 5.0, and4.5 × 104 for β-livetin. Under suitable conditions of sedimentation and electrophoresis, egg yolk has been shown to contain three components having the same behavior as the three livetins of the water-soluble fraction.


Chemosphere ◽  
2010 ◽  
Vol 78 (11) ◽  
pp. 1301-1312 ◽  
Author(s):  
S.M. Rodrigues ◽  
B. Henriques ◽  
J. Coimbra ◽  
E. Ferreira da Silva ◽  
M.E. Pereira ◽  
...  

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