Amphibia Kupffer cells

Abstract

Amphibia Kupffer cells (i.e., liver resident macrophages) show many common characteristics when compared with Mammalia Kupffer cells: filopodia, microvillous-like structures, lamellipodia, fuzzy coat, coated vesicles, bristled vacuoles, nonspecific esterase activity, and pinocytotic and phagocytic activity are present both in Amphibia and Mammalia Kupffer cells. On the other hand, some differences are present between Kupffer cells of both zoological classes: phagocytosed red cells and their derivatives, iron-protein complexes, and lipofuscin bodies are normally present in Amphibia Kupffer cells, but absent in the same cells of healthy mammals. Worm-like structures are not seen in Amphibia and endogenous peroxidase activity is very weak in these animals compared with Mammalia. The most important difference lies in the ability of Amphibia Kupffer cells to produce melanins: in fact the tyrosinase gene is expressed, "melanosome centers" are present, and dopa oxidase activity is demonstrable.

Using itraconazole to clear Batrachochytrium dendrobatidis infection, and subsequent depigmentation of Alytes muletensis tadpoles

“…The depigmentation we observed in our experimental tadpoles suggests that the production of melanin may in some way have been impaired by itraconazole treatment. Melanin is produced in many cells including the Kupffer cells in amphibian livers (Sichel et al 2002). Additionally, hepatotoxic side effects of itraconazole have been reported in mammals (Collazos et al 1995, Somchit et al 2004; therefore, before itraconazole is adopted as a general treatment for larval amphibians, we suggest more research be undertaken to identify any potential side effects of this antifungal agent.…”

Comparative Histological Study of Parenchymal Arrangements in Three Orders of Reptilian Livers

“…Although hematopoiesis has been examined extensively in mammals whose adult hematopoietic stem cells reside predominantly in the bone marrow [28], it is poorly understood in non-mammalian vertebrates. In amphibians, MMs are particularly numerous in the portal area [13], and hematopoietic tissue has been located in the portal triad and perihepatic subcapsular region in the orders Urodela and Gymnophiona; however, these were absent in the order Anura (except for the genus Xenopus) [6]. In contrast, there have been a few studies among each order in reptilians.…”

“…Aggregations of pigmented cells, termed MMs, have been found in the livers of some fishes [8,9], amphibians [10][11][12][13], and reptiles [14][15][16][17]. Previous studies demonstrated that the pigmented cells of amphibian livers are cells belonging to the macrophage lineage of Kupffer cells [23][24][25] as well as the MMs centers of fishes [19,26,27].…”

“…Extracutaneous melanin-containing cells have been detected in various tissues and organs such as the liver, spleen, kidney, and lungs [9,18,19]. MMs of the liver are mainly localized in the endothelial walls of sinusoids anchored to endothelial cells that sometimes protrude into the lumen [13]. While the existence of MMs in many evolutionarily divergent orders of heterothermic vertebrates has not yet been determined, it is surmised that these cells are beneficial for poikilotherms, since they are not present in birds or mammals [15].…”

“…In heterothermic vertebrates, aggregations of pigmented cells termed melanomacrophages (MMs) have been identified in the livers of some fishes [8,9], amphibians [10][11][12][13], and reptiles [14][15][16][17]. Extracutaneous melanin-containing cells have been detected in various tissues and organs such as the liver, spleen, kidney, and lungs [9,18,19].…”