Carp liver

Molinate Metabolism in Carp Hepatic Mixed-function Oxidase System. Incubation of molinate with carp liver microsomes produced four major organosoluble metabolites (molinate sulfoxide, 3- and 4-hydroxy molinate, and keto HMI). Parameters affecting... 

Figure 3. Effect of temperature on conversion of molinate to its sulfoxide by carp liver microsomal mfo (liver microsomal protein 6 mg/mL, pH 7.4, NADPH 3 mg incubated for 15 min)...

Figure 4. Effect of carp liver microsomal protein concentration on its mfo activity (NADPH 3 mg/mL, pH 7.4 incubated for 15 min at 25°C)...

Figure 5. Effect of incubation time on the carp liver microsomal mfo activity (NADPH 2 mg/mL, pH 7.4 incubated at 25° C. Microsomal protein concentration...

Figure 6. Chromatographic pattern for carp liver microsomal 14C-labeled organo-soluble metabolites of [ring-14C]-molinate. Incubation was conducted under standard conditions for one hr m number represents metabolite code.

North Dakota and Minnesota, Red River of the North, 1994 Common carp Liver Muscie Whoie... 

Schiinke, M. and Wodtke, (1983). Cold-induced increase of delta 9- and delta 6-desat-urase activities in endoplasmic membranes of carp liver. Biochirruca et Biophysica Acta 734,70-75. 

Hoshita et al. have shown that liver microsomes from the green iguana, in which the major biliary bile salt is tauroallocholate, convert 7a,12a-dihydroxycholest-4-en-3-one (XVII) into 5a-cholestane-3a,7a,12a-triol (XVIII) rather than into 5)8-choles-tane-3 ,7a,12a-triol (VIII) which is involved in cholic acid biosynthesis [164]. On the basis of this result and that obtained from studies with carp liver [151], it can be assumed that 5a-bile acids and alcohols are formed from cholesterol by a modification of the biosynthetic pathway to the corresponding 5y8 isomers in which the only difference is the stereospedfic saturation of the A double bond of the intermediate XVII. 

To ascertain whether cholesterol is a precursor of 5a-cyprinol, Hoshita (133) administered C-cholesterol intraperitoneally to carp, in which 5a-cyprinol is the principal biliary sterol (134). After 12 days bile was collected from the gallbladder, and radioactive 5a-cyprinol corresponding to 0.14% of the administered sterol was recovered from bile. To ascertain whether choles-tanol or 7a-hydroxycholesterol was a precursor of 5a-cyprinol in this species Hoshita (58) administered these tritiated sterols intraperitoneally to carp and studied the distribution of in biliary constituents. From cholestanol-5,6- H, 1.1% of the biliary remained in the neutral fraction, of which 5a-cyprinol and 27-deoxy-5a-cyprinol were the major and minor constituents ( 22 1). Allocholic acid was the only radioactive component identified in the acid fraction. Two weeks after similar injection of 7a-hydroxycholesterol-7/S- H into carp, 17.6% of the radioactivity was recovered in bile, 86.5% of which was present in the neutral fraction and 6.3 % in the acid fraction. 5a-Cyprinol and 27-deoxy-5a-cyprinol ( 9 1) retained most of the tritium in the former fraction, whereas allocholic and cholic acids each retained ( 1.5 1) in the acid fraction. Thus, carp liver enzymes convert 7a-hydroxy-cholesterol to 5a sterols and to the 5/9- and 5a-C24 acids. Normally carp bile contains more cholic than allocholic acid. 

Masui et al. (136) have shown that carp liver microsomes contain the necessary 5a-reductase and a 26-hydroxylase to convert 7a,12a-dihydroxy-cholest-4-en-3-one (XXXVI) to 27-deoxy-5a-cyprinol when fortified with NADPH, and that a mitochondrial enzyme system requiring NADPH converts the latter 5a-sterol to 5a-cyprinol. They suggested that the microsomal system hydroxylated one of the terminal methyl groups in a stereospecific form (25 -form), and the mitochondrial system hydroxylated the 25a-form. 

---