Farklı aminoasitlerle zenginleştirilmiş Artemia naupli`leri ile beslenen çipura balığı(Sparus auratus, Linneaus 1758)`nın sindirim hormonları ve enzimlerindeki değişimler

Abstract

IÖZETFARKLI AMINOASITLERLE ZENGINLESTIRILMISARTEMIA NAUPLI'LERI ILE BESLENEN ÇIPURA BALIGI(Sparus auratus, Linneaus1758)'NIN SINDIRIM HORMONLARI VEENZIMLERINDEKI DEGISIMLERBu çalismada, çipura(Sparus auratus) larvalarinin 28. günden 40. güne kadarsindirim hormonlari ve enzimleri üzerine serbest aminoasitlerin etkileri her biri 4günlük 4 periyotta incelenmistir. Ayni zamanda çipura larvalarinin 24. güne kadar olanenzimsel aktiviteleri de standart besleme protokolü ile gözlenmistir. Ayrica sindirimkapasitesinin iyi bir indikatörü olmasindan dolayi aminopeptidaz N/lösin-alaninpeptidaz oranlari hesaplanmistir. Deneme baslamadan önce, yumurtadan çikan keselilarvalar 300 litrelik 9 adet tanka tesadüfû olarak dagitilmis ve 15. güne kadar rotifer, 24.güne kadar Artemia naupli ve daha sonra balik larvalari için esansiyel olarak bilinenfarkli bireysel aminoasitlerle zenginlestirilmis Artemia metanaupli'leri ilebeslenmislerdir. Deneme gruplari histidin, lösin, isolösin, lisin, metiyonin, fenilalanin,treonin, valin ve kontrol(serbest aminoasit zenginlestirmesiz) grubudur.IV. periyotta, en iyi larval agirlik ve boy sirasiyla isolösin ve fenilalanin serbestaminoasit gruplarindan elde edilmistir(P<0.05). Enterosistlerin sitozolünde bulunanlösin-alanin peptidaz aktivitesi tüm gruplarda çalisma boyunca yüksek bulunmustur. IV.periyotta kontrol grubunda gözlenen lösin-alanin peptidaz aktivitesi, serbest aminoasitgruplarininkinden daha yüksek bulunmustur (P<0.05). Muamele gruplarininortalamalari açisindan en düsük lösin-alanin peptidaz aktivitesini kontrol grubugöstermistir. IV. periyotta lösin, fenilalanin, isolösin, lisin ve valin gruplariaminopeptidaz N/lösin-alanin peptidaz orani bakimindan iyi bir sindirim kapasitesigöstermistir. Buna karsilik muamele gruplarinin ortalamalari açisindan en iyi sindirimkapasitesinin kontrol grubunda oldugu tespit edilmistir (P<0.05).Tripsin enzimaktivitesinin larvanin yasina bagli olarak I. periyot'a kadar arttigi gözlenmistir.Tripsin'in besinsel adaptasyonunu kont rol eden mekanizmanin III. periyot'a kadar etkinolmadigi tespit edilmistir. Elde edilen sonuçlara göre, farkli serbest aminoasitlerlezenginlestirilmis canli yemlerle larval besleme, bombesin (GRP) ve kolesistokinin(CCK)'in hormonal aktivitelerine katkida bulunmustur (P<0.05).2007, 97 sayfaAnahtar Kelimeler: Sparus auratus, bombesin, kolesistokinin,lösin-alanin peptidaz,alkalin fosfataz , aminopeptidaz N,tripsin,Artemia naupli

IIABSTRACTTHE CHANGES IN DIGESTIVE ENZYMES AND HORMONES OFGILTHEAD SEA BREAM LARVAE (Sparus auratus, L 1758) FED ONARTEMIA NAUPLI ENRICHED WITH DIFFERENT AMINO ACIDSThe effects of free amino acids on the digestive hormones and enzymes ofgilthead seabream (Sparus aurata L.) from day 28th to day 40th were investigated in 4periods, 4 days each. Enzymatic activities of gilthead seabream larvae were alsoobserved by applying a standard feeding protocol until day 24th . Morever, the ratios ofleucine-alanine peptidase (lap/leu-ala) were calculated because it is a good indicator ofthe digestive capacity. Prior to initiation of the experiment, newly hatched yolk-saclarvae were randomly distributed into each of nine 300- liter tanks and fed with rotiferuntil day 15th after then with Artemia nauplii until day 24th . After day 24th , seabreamlarvae were fed on Artemia nauplii enriched with the different individual amino acidsthat known as the indispensable for fish larvae. Experimental groups were histidine,leucine, isoleucine, lysine, methionine, phenylalanine, threonine, valine and control(without free amino acid enriched).In period IV, the best larval weight and length were obtained in isoleucine andphenylalanine free amino acid groups, respectively (P<0.05). The activities of the leu-ala peptidase located in the cytosol of enterocytes were high in all groups through theentire study. Leu-ala peptidase level observed in the control group was higher than thatof free amino acid enriched groups, especially, in IV. period(P<0.05). The control groupshowed the lowest leu-ala peptidase activities comparing the average of treatmentgroups. Leucine, phenylalanine, isoleucine, lysine and valine groups showed gooddigestive capacity in IV. period with respect to lap/leu-ala peptidase ratio s. However,control group showed the best digestive capacity compared to averages of the treatmentgroups(P<0.05). An increase in tryptic enzyme activity was observed as a function ofthe larval age from the beginning until I. period. The results revealed that themechanism controlling the adaptation of trypsin activity depending on the amount offree amino acids were inactive until III. period. It might be concluded according to theresults of the present study that the larval feeding on live prey enriched with differentessential amino acids stimulate the hormonal activity of bombesin (GRP) andcholecystokinin (CCK) (P<0.05).2007, 97 pagesKey words: Sparus auratus, bombesin, cholecystokinin , leucine-alanine peptidase,alkaline phosphatase, aminopeptidase N, trypsin, Artemia naupli