Macrophage centers in fish liver-histological biomarkers of stress

Abstract

U posljednjih stotinu godina došlo je do velikog povećanja zagađenja okoliša. Ribe kao stanovnici najugroženijih ekosustava dolaze u doticaj sa zagađivačima od kojih se veliki dio bioakumulira u njihovom organizmu pa se zato smatra da su ribe pogodne kao biološki indikatori onečišćenja. Melano-makrofagni centri su nakupine pigmentiranih stanica u tkivima koje normalno možemo pronaći kao dio strome hematopoetskog tkiva u slezeni i bubregu te u jetri riba. Izgled melano-makrofagnih centara može varirati među vrstama, organima i fiziološkim stanjima unutar iste vrste. U njima možemo naći tri osnovne vrste pigmenata: melanin, lipofuscin i hemosiderin, a porijeklo i biokemijska uloga tih pigmenata varira i nije još u potpunosti poznata. Pretpostavlja se da je primarna funkcija tih centara uništavanje, detoksifikacija i reciklaža endogenog i egzogenog staničnog materijala. Osim funkcije “skupljača smeća”, melano-makrofagni centri smatraju se i filogenetskim prekursorom zametnih centara limfnih čvorova. Eksperimentalno je dokazano da su melanomakrofagni centri u jetri pogodni kao histološki biomarkeri stresa, no potrebno je uzeti u obzir parametre poput starosti jedinke, spola, spolne zrelosti i okolišnih faktora.In the last hundred years there was a large increase in enviromental pollution. Fish come in contact with pollutants, of which a large part bioaccumulate in their body and are therefore believed to be suitable as biological indicators of pollution. Melano-macrophage centers are clusters of pigmented cells that can normally be found as a part of hematopoetic tissue in spleen and kidney but also in the fish liver. The appearance of melano-macrophage centers can vary between species, organs and physiological conditions within the same species. There we can find three basic types of pigments: melanin, lipofuscin and haemosiderin, but the origin and biochemical role of those pigments varies and is not yet fully known. It is assumed that the primary function of those centers is destruction, detoxification and recycling of endogenous and exogenous cellular material. Apart from being "garbage collectors," melano-macrophage centers are considered as phylogenic precursors of germ centers of lymphatic nodes. It is experimentally shown that melano-macrophage centers, found in liver, are biologically suitable to be used as indicators of stress, but it is necessary to take into consideration variable parameters such as age, sex, sexual maturity and environmental factors