scholarly journals Some metabolites of 1-bromobutane in the rabbit and the rat

1968 ◽  
Vol 109 (5) ◽  
pp. 727-736 ◽  
Author(s):  
Sybil P. James ◽  
D. A. Jeffery ◽  
Rosemary H. Waring ◽  
P. B. Wood
Keyword(s):  
Lactic Acid ◽  
Ethyl Ester ◽  
Rat Liver ◽  
Hydroxy Acid ◽  
Rabbit Liver ◽  
Mercapturic Acid ◽  
Acid Form ◽  
Rat Urine ◽  
Glycine Ethyl Ester

1. Rabbits and rats dosed with 1-bromobutane excrete in urine, in addition to butylmercapturic acid, (2-hydroxybutyl)mercapturic acid, (3-hydroxybutyl)mercapturic acid and 3-(butylthio)lactic acid. 2. Although both species excrete both the hydroxybutylmercapturic acids, only traces of the 2-isomer are excreted by the rabbit. The 3-isomer has been isolated from rabbit urine as the dicyclohexylammonium salt. 3. 3-(Butylthio)lactic acid is formed more readily in the rabbit; only traces are excreted by the rat. 4. Traces of the sulphoxide of butylmercapturic acid have been found in rat urine but not in rabbit urine. 5. In the rabbit about 14% and in the rat about 22% of the dose of 1-bromobutane is excreted in the form of the hydroxymercapturic acids. 6. Slices of rat liver incubated with S-butylcysteine or butylmercapturic acid form both (2-hydroxybutyl)mercapturic acid and (3-hydroxybutyl)mercapturic acid, but only the 3-hydroxy acid is formed by slices of rabbit liver. 7. S-Butylglutathione, S-butylcysteinylglycine and S-butylcysteine are excreted in bile by rats dosed with 1-bromobutane. 8. Rabbits and rats dosed with 1,2-epoxybutane excrete (2-hydroxybutyl)mercapturic acid to the extent of about 4% and 11% of the dose respectively. 9. The following have been synthesized: N-acetyl-S-(2-hydroxybutyl)-l-cysteine [(2-hydroxybutyl)mercapturic acid] and N-acetyl-S-(3-hydroxybutyl)-l-cysteine [(3-hydroxybutyl)mercapturic acid] isolated as dicyclohexylammonium salts, N-toluene-p-sulphonyl-S-(2-hydroxybutyl)-l-cysteine, S-butylglutathione and N-acetyl-S-butylcysteinyl-glycine ethyl ester.

scholarly journals The metabolism of benzyl isothiocyanate and its cysteine conjugate

1977 ◽  
Vol 162 (1) ◽  
pp. 99-107 ◽  
Author(s):  
G Brüsewitz ◽  
B D Cameron ◽  
L F Chasseaud ◽  
K Görler ◽  
D R Hawkins ◽  
...  
Keyword(s):  
Oral Dose ◽  
Rat Liver ◽  
Hippuric Acid ◽  
Reduced Glutathione ◽  
Mammalian Species ◽  
Mercapturic Acid ◽  
Acid Biosynthesis ◽  
Rat Urine ◽  
Benzyl Isothiocyanate ◽  
Rat Liver Cytosol

1. The corresponding cysteine conjugate was formed when the GSH (reduced glutathione) or cysteinylglycine conjugates of benzyl isothiocyanate were incubated with rat liver or kidney homogenates. When the cysteine conjugate of benzyl isothiocyanate was similarly incubated in the presence of acetyl-CoA, the corresponding N-acetylcysteine conjugate (mercapturic acid) was formed. 2. The non-enzymic reaction of GSH with benzyl isothiocyanate was rapid and was catalysed by rat liver cytosol. 3. The mercapturic acid was excreted in the urine of rats dosed with benzyl isothiocyanate or its GSH, cysteinyl-glycine or cysteine conjugate, and was isolated as the dicyclohexylamine salt. 4. An oral dose of the cysteine conjugate of [14C]benzyl isothiocyanate was rapidly absorbed and excreted by rats and dogs. After 3 days, rats had excreted a mean of 92.4 and 5.6% of the dose in the urine and faeces respectively, and dogs had excreted a mean of 86.3 and 13.2% respectively. 5. After an oral dose of the cystein conjugate of [C]benzyl isothiocyanate, the major 14C-labelled metabolite in rat urine was the corresponding mercapturic acid (62% of the dose), whereas in dog urine it was hippuric acid (40% of the dose). 5. Mercapturic acid biosynthesis may be an important route of metabolism of certain isothiocyanates in some mammalian species.

Glucocorticoid effects on respiration and metabolism by rat liver homogenates

1962 ◽  
Vol 202 (2) ◽  
pp. 343-346 ◽  
Author(s):  
Dennis D. Goetsch ◽  
L. E. McDonald
Keyword(s):  
Lactic Acid ◽  
Oxygen Uptake ◽  
Rat Liver ◽  
Inorganic Phosphate ◽  
Chronic Administration ◽  
Glucocorticoid Treatment ◽  
Carbohydrate Utilization ◽  
Protein Levels ◽  
Liver Homogenates ◽  
And Control

The effects of glucocorticoid administration on oxygen uptake, glucose and glycogen disappearance, lactic acid formation, and inorganic phosphate and protein levels in rat liver homogenates have been studied. A single injection of hydrocortisone, prednisolone, or 9 α-fluoroprednisolone 5 hr before sacrifice resulted in a highly significant increase in oxygen uptake by rat liver homogenates, whereas chronic administration of prednisolone daily for 7 days caused a marked inhibition in homogenate respiration. Glycolytic rate did not appear to be affected by single injections since endogenous carbohydrate utilization was similar in liver homogenates prepared from control and treated animals. Incubation of liver homogenates under aerobic conditions disclosed that inorganic phosphate levels were decreased in homogenates from corticoid-treated rats, whereas these levels were similar in treated and control liver homogenates incubated under nitrogen. Under anaerobic conditions, liver homogenates from treated rats accumulated lactic acid more rapidly than untreated liver homogenates. Glucocorticoid treatment did not appear to affect protein disappearance since no differences between protein levels in treated and untreated rat liver homogenates were detected following incubation.

Iron-Catalyzed Cyclopropanation with Glycine Ethyl Ester Hydrochloride in Water

2012 ◽  
Vol 14 (8) ◽  
pp. 2162-2163 ◽  
Author(s):  
Bill Morandi ◽  
Amund Dolva ◽  
E. M. Carreira
Keyword(s):  
Ethyl Ester ◽  
Ester Hydrochloride ◽  
Glycine Ethyl Ester

Protection of Corn (Zea mays) from Acetanilide Herbicidal Injury with the Antidote R-25788

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 653-659 ◽  
Author(s):  
J. R. C. Leavitt ◽  
Donald Penner
Keyword(s):  
Zea Mays ◽  
Ethyl Ester ◽  
Isopropyl Ester ◽  
Weed Species ◽  
Greenhouse Study ◽  
Glycine Ethyl Ester

The antidote R-25788 (N,N-diallyl-2,2-dichloroacetamide) protected corn (Zea mays L. ‘DeKalb 315A’) seedlings from injury caused by the acetanilide herbicides, alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], H-22234 [N-chloroacetyl-N-(2,6-diethylphenyl)glycine ethyl ester], and H-26910 [N-chloroacetyl-N-(2-methyl-6-ethylphenyl)glycine isopropyl ester] in a greenhouse study. R-25788, however, did not protect four weed species tested. R-25788 only partially protected corn from injury caused by acetochlor [2-chloro-N-(ethoxymethyl)-6′-ethyl-o-acetotoluidide]. R-25788 was an effective antidote whether applied preemergence, preplant-incorporated, or as a tank mix. Injury symptoms caused by EPTC (S-ethyl dipropylthiocarbamate) and the acetanilide herbicides were similar; both caused leaf twisting and rolling, and at high rates leaves failed to emerge through the coleoptile.

Efficient hepatic uptake and concentrative biliary excretion of a mercapturic acid

1998 ◽  
Vol 275 (4) ◽  
pp. G612-G619 ◽  
Author(s):  
Cheri A. Hinchman ◽  
James F. Rebbeor ◽  
Nazzareno Ballatori
Keyword(s):  
Rat Liver ◽  
Biliary Excretion ◽  
Organic Anion ◽  
Hepatic Uptake ◽  
Mercapturic Acid ◽  
Whole Body ◽  
Isolated Perfused Rat Liver ◽  
Mercapturic Acids ◽  
Anion Transporters ◽  
Subsequent Degradation

The role of the liver in the disposition of circulating mercapturic acids was examined in anesthetized rats and in the isolated perfused rat liver using S-2,4-dinitrophenyl- N-acetylcysteine (DNP-NAC) as the model compound. When DNP-NAC was infused into the jugular vein (150 or 600 nmol over 60 min) it was rapidly and nearly quantitatively excreted as DNP-NAC into bile (42–36% of the dose) and urine (48–62% of dose). Some minor metabolites were detected in bile (<4%), with the major metabolite coeluting on HPLC with the DNP conjugate of glutathione (DNP-SG). Isolated rat livers perfused single pass with 3 μM DNP-NAC removed 72 ± 9% of this mercapturic acid from perfusate. This rapid DNP-NAC uptake was unaffected by sodium omission, or byl-cysteine,l-glutamate,l-cystine, or N-acetylated amino acids, but was decreased by inhibitors of hepatic sinusoidal organic anion transporters (oatp), indicating that DNP-NAC is a substrate for these transporters. The DNP-NAC removed from perfusate was promptly excreted into bile, eliciting a dose-dependent choleresis. DNP-NAC itself constituted ∼75% of the total dose recovered in bile, reaching a concentration of 9 mM when livers were perfused in a recirculating mode with an initial DNP-NAC concentration of 250 μM. Other biliary metabolites included DNP-SG, DNP-cysteinylglycine, and DNP-cysteine. DNP-SG was likely formed by a spontaneous retro-Michael reaction between glutathione and DNP-NAC. Subsequent degradation of DNP-SG by biliary γ-glutamyltranspeptidase and dipeptidase activities accounts for the cysteinylglycine and cysteine conjugates, respectively. These findings indicate the presence of efficient hepatic mechanisms for sinusoidal uptake and biliary excretion of circulating mercapturic acids in rat liver and demonstrate that the liver plays a role in their whole body elimination.

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