S Lafond | PubMed Health

PubMed2001

Changes in lipids and sterols during composting.

Pyrolysis-gas (Py-GC) chromatography was used to characterize organic [(diethyl ether (DEE) and chloroform (CHCl3)] extracts of raw and composted duck excreta enriched wood shavings from two finishing cycles (C1 and C2). Materials were collected on days 0, 8 and 23. C1 contained 1.7 % total N while C2 contained 0.9 % total N. Py-GC-MS (mass spectrometry) showed that the extracts contained n-alkanes (C12 to C32), alkenes (C12:1 to C33:1), n-fatty acids (C12 to C28), unsaturated fatty acids (C18:1 and C18:2), and sterols (cholestene, cholestadiene, stigmastene, stigmastadiene, stigmastatriene, cholesterol, stigmastanol, stigmastanone, stigmastadienone, 17-methyl dialkylsulfanyl decahydro-1H-cyclopenta [a] phenanthrene, 17-methyl dialkylsulfanyl dodecahydro-1H-cyclopenta [a] phenanthrene, and 17-methyl-17-dialkylsulfanyl decahydro-1H-cyclopenta [a] phenanthrene). Other components identified were prystene, squalene (precursor of cholesterol), phthalic acid, diphenylpropane, diphenylbut-2-ene and 1,3,6 triphenyl hex-4-ene. Our data showed significant changes in the lipid composition of duck excreta enriched wood shavings during composting, which appeared to be related to the total N content of the system.

Animals↗

PubMed1994

Effect of inhibition of hepatic fatty acid oxidation on metabolic and hormonal responses to exercise in rats.

The purpose of the present study was to assess the effects of 2-mercaptoacetate (MA), an inhibitor of hepatic fatty acid oxidation, on the metabolic and pancreatic hormone response to a prolonged (3 h) swimming exercise. All rats were first adrenodemedullated and were either submitted for 3 weeks to a normal (5% fat) or a medium-fat diet (MF; 18% fat). After being submitted to an exercise swimming habituation programme for one week, rats under both dietary conditions were either injected with a bolus dose of MA (600 mumol/kg; ip) or with a saline solution. MA and saline injected rats were either sacrificed after a 3-h swimming exercise or after a 3-h resting period. Administration of MA was associated with a lower level of beta-hydroxybutyrate after exercise in rats fed the MF diet, higher resting and exercising blood glucose levels in rats fed the MF diet, and higher resting and exercising levels of hepatic glycogen in rats fed a normal diet. There were, however, no significant effects of MA on free fatty acid, insulin, glucagon, epinephrine, and norepinephrine concentrations in both dietary conditions either at rest or after exercise. Therefore, the present data do not provide any evidence that the administration of MA, an inhibitor of hepatic fatty acid oxidation, influences the pancreatic hormonal response to exercise. There was also no evidence of a lowering effect of MA on blood glucose levels during exercise.

3-Hydroxybutyric Acid↗