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Nucleotide Degradation and Production of Hypoxanthine in Some Indian Marine and Freshwater Fishes

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Nucleotide Degradation and Production of Hypoxanthine in Some Indian Marine and Freshwater Fishes Nucleotide degradation and production of hypoxanthine in some Indian marine and freshwater fishes Item Type article Authors Ramanath, S.; Velankar, N.K. Download date 25/09/2021 04:47:05 Link to Item http://hdl.handle.net/1834/33735 ClEOTI E HY I IN E f FIS ES S. RAl\.IANATH* AND N. K. VEI.. ANKAR** .Central lns.titute of Fisheries Education, Bymbay-400061 Changes in nucleotides and production of hypoxanthine in rohu (Labeo rohita), mrigal (Cihhrina mrigala) and common carp (Cyprins carpio) during storage at 2- 4°C were examined. Differences were observed between common carp and others. Production of hypoxanthine in pomfret (Stromateus argenteus), cat fish (Arius macronotacanthus), shark (Scoliodon spp.), seer fish (Scomberomorus guttatus), ray fish (Dasyatis imbricata) and prawns. (Parapenaeopsis stylifera) was examined during storage at 2-4°C and -28°C. At 2-4°C hypoxanthine increased regularly but at -2R°C there was no increase during storage over 28 weeks. INTRODUCTION Stroud and Jones 1969; Dingle and Hines, 1971). The HYP test has the advantage Adenosine-5-triphosphate (ATP) and over other objective tests such as tri­ the products of degradation of fish muscle methylamine (TMA), total volatile base post-mortem have received considerable (TVB) etc., since it is sensitive in the attention in recent years. The accumul­ early stage of storage in ice before signi­ ation of hypoxanthine (HYP) has attracted ficant bacterial activity sets in. ]t could particular attention as its content is an be useful in determining the pre-freezing index of quality /freshness of fish (Kas­ quality of fish (Hiltz et al., 1966). It is semsarn et al., 1963; Jones, 1965; Burt, cons-idered particularly useful in the case Present address: *Dept. of Biochemistry, Indian Institute of Science, Bangalore. **Dept. of Industrial Fisheries, University of Cochin, Ernakulam, Cochin-16. 3~ Part of Thesis for M.Sc. degree in Biochemistry of the University of Bombay by the first author. 92 Fish. Techno! 'Ramanatl! & Velm1/{ar: Nucleotide degradation ancl production of l!vpoxantfline of irradiated fish (Spinelli, Pelroy and of the Institute's. fishing vessel 'MFV Miyauchi, 1969) and freshwater fish (Bligh, Harpodon'. The fish had usually remained 1971). However, wide variations have at the ambient temperature (about 30°C) been reported in the rate of accumulation for nearly 4 hours prior to being examined of HYP in the different fish species m the laboratory. examined (Fraser, Simpson and Dyer, 1968; Fraser, Pilts and Dyer, 1968; Dingle and The nucleotides and other biochemicals Hines, 1971 ). It is necessary therefore used were of E. Merck and Fluka. All to know the changes occurring in all other chemicals employed in the analysis species of fish if the test is to be employed were of A. R. grade. The xanthine oxidase in practice. No attempt has been made enzyme was prepared from buffalo's milk so far in Tndia in carrying out systematic 111 the laboratory employing the method studies of this nature though reports of Dixon and Kodama (1926). relating to nucleotides in fish musd:: post­ mortem have been published (Cherian and The freshwater fishes were killed by Nair, 1969; Rao, Rangaswamy and Lahiri, a blow on the head, immediately evis- 1969). Hence the present studies were cerated and stored in refrigerator· undertaken on some species of marine (2-4°C) in polyethylene bags. The marine and freshwater fishes available in Bombay. fishes were eviscerated and stored m The studies on the freshwater fishes were crushed ice. For the ::->bserva1ion during aimed at elucidating the stepwise break­ frozen storage the fish were packed in down occurring in the nucleotides soon polyethylene bags and kept in a freezer 0 after death of the fish while those on ( -21< C). Samples of muscles were taken marine fish were meant primarily to at regular intervals from the dorso-lateral evaluate the accumulation of HYP during portion of the fish starting from behind storage of the fish in chilled and frozen the head and moving back up to the condition. The results are reported and region of the tail. In the case of discussed in the present paper. prawns all the muscle from two to three specimens were blended together and a MATERIALS AND METHODS portion of it was used for the preparation of the extracts. Dark muscle was sepa­ The freshwater fishes common ca;:p rated completely from white muscle before (Cyprinus carpio), rohu (Labeo rohita) and the extraction as hypoxanthine is known mrigal ( Cirrhina mrigala) were obtained to accumulate at different rates in dark from a lake in Thana, near Bombay. muscle as compared with white muscle. These were held alive in aquarium tank and used for the experiments after resting The fish were sampled as described them for a week. The marine fish pomfret by Dugal (1967). Perchloric acid extracts (Stromateus argenteus), cat fish (Arius were prepared by the method outlined by macronotacanthus), sharks ( Scoliodon pala­ Jones and Murray (1964). 5 g. of the sorrah, Scoliodon srorakowah), ray fish white muscle was homogenised with 5ml. (Dasyatis imbricata), seer fish (Scomberom­ of 10% trichlor acetic acid (TCA), cen­ orus guttatus) and prawns (Parapenaeopsis trifuged, and the supernatent made up to stylifera), were obtained from the catches 20 ml. with 1% TCA. VoL 14 No. 2 1977 93 Fig. f Fig. 2 MEAN VALUESO'F' HYPOXANTHINE HYPOXANTHlNEIN ROHU 3·0 ~3"-0 E E "' ~ U) 'w w .J ' "'...J 0 2·0 ~2-0 ::;: ~ .3 w w :z z ::c i= 1-0 ;;; 1·0 <t X X 0 0 Q_ Q_ ,_ >- :c. :c. 3 7 II 15 7 II 15 DAYS AT (2-4°€:} DAYS AT (2-4°C) 3·0 Fig. 4 ~ ~ E 3-0 HYPOXANTHINE E HYPOXANTHiNE IN COMMON CARP' "" ~ ' U) w w "'...J .J 02·0 0 ::;: ::;: 2· 3 .3 w w :z z I ::c .,.. t- 1·0 z <t 1>!1 X X 0 0 a. a. >- )-· ~ ::c 15 3 7 II 15 DAYS AT(2-4°C) Hypoxanthine was estimated by the rohu, mrigal and common carp at refri­ method outlined by Kalckar (1947) as geration temperature (2-4"C) are shown modified by Jones and Murray (1964). in Fig. L The rate of accumulation is In this method hypoxanthine is oxidised similar in rohu and mrigai and is signi­ to uric acid and the absorption at 290mfl ficantly greater than in common carp. due to formation of uric acid was Values of hypoxanthine in individual fish determined using Zeiss PQ Spectropho­ are shown m Fig. 2-4, which clearly tometer. indicate the range of variation occurring among individuals of the same species. The batchwise ion exchange method of Jones and Murray (1964) was employed The changes in the adenine nucleo­ for the estimation of inosine and nucleo­ tides occurring in these three fishes are tides. shown in fig. 5. In both rohu and mrigai the adenine nucleotides reach 0 level after RESULTS AND DISCUSSION 15 days but in common carp the level remains quite high after the same period. The mean values of hypoxanthine accumulated during 15 days' storage of Changes occurnng m the inosine 94 Fish. Technol. 'Ramanatfl & V elm&ar: NucleotiJe degradation and production of ftypoxantfline monophosphate (IMP) concentration during three cases, after an initial increase in the storage at 2 - 4°C for the three species first few days there was no subsequent are shown in fig. 6. In rohu the maxi­ rise throughout the storage period. mum value is reached after a week and it remains fairly high i.e. 2flmolesjg. There is practically little HYP dete­ muscle, on the 15th day; in mrigal the ctable in the freshly killed carps but initial value is higher than in rohu and it increases regularly during storage at falls during storage to 2flmoles/g. on 2-4°C in all the three species. There is the 15th day. In common carp the initial considerable variation among the indivi­ value is higher than in rohu and mrigal duals of the same species However, the but faHs -rapidly to 1 flmolejg. by the mean values of HYP accumulation during 15th day. storage indicate clearly that the rate of accumulation is higher in rohu and mri­ Changes 1n the inosine concentration gal than in common carp. The changes during storage are shown 1n fig. 7. in the concentration of the adenine The increase in inosine is rapid in the nucleotides during storage followed a clo­ case of the common carp compared With sely similar pattern in rohu and mrigal the rate of increase in rohu and mrigal. differed from common carp in which a Fig. 8 shows the comparative activity higher level was maintained throughout the 15 days' storage whereas in rohu and of the enzyme 5'nucleotidase in common mrigal the adenine nucleotides could not carp and rohu. In comn1on carp the be detected by the 15th day (fig. 5). activity is much greater compared with Other studies carried out in this laboratory that in rohu. (Nayak, 1975 unpublished observation) The HYP produced in the marine indicate that the rate of bre-akdown of fishes, sharks, pomfret, cat fish and ray fish, glycogen is slower in common carp com­ during storage in ice for 15 days is shown pared with that in rohu and mrigal. In in fig. 9. The initial values of HYP are view of the close association of glycolysis higher than in the freshwater fishes, pro­ with rhe A TP cleavage mechanism the bably because some time had elapsed comparatively higher level of adenine between death of the fish and the sampling nuc]eotides persisting longer in common carried out in the laboratory before com­ carp can probably be explained.
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