Uptake of Foreign Ferritin in Heart of Firemouth Cichlid (Cichlidae: Teleostei)

Abstract

The ultrastructure of the endothelium in the heart of the firemouth cichlid (Thorichthys meeki) and its capability and capacity to take up foreign ferritin are described. The entire wall in atrium and ventricle was spongy and composed of muscle trabeculae, covered by endothelial cells which were about 4-6-lm thick in atrium and flat in ventricle. These cells contained a number of moderately electron-dense bodies (MDBs, diameter 2 lm and less), clathrin-coated vesicles, and tubules of agranular endoplasmatic reticulum. Numerous yellow-brown granules, width 2 lm and less, occurred in the endocardial endothelium covering the cardiac muscle trabeculae in ferritin-injected firemouth cichlid 8 hr postinjection; much Prussian blue precipitated within these granules when treated with acid ferrocyanide. When the time between the injection and sacrifice was extended to 24 hr, the granules and Prussian blue precipitations in the corresponding endocardial endothelium displayed a width of 3 lm and more. The endocardial endothelium facing the cardiac main lumen or covering the valves and walls of the atrio-ventriclar or ventriculo-bulbar apertures nearly lacks such granules and precipitations as well as MDB, clathrin-coated vesicles and tubules of agranular endoplasmic reticulum, suggesting that the endothelium at these sites is not endocytic. Lipofuscinlike pigments were demonstrated by the Schmorl's technique in the endocardial endothelium covering the heart muscle trabeculae in firemouth cichlid. Together these findings suggest that the endocardial endothelium cover on the muscle trabeculae in heart wall in firemouth cichlid is highly specialized to play important roles in the uptake of scavenger molecules and foreign particles. Such an uptake may be very efficient as this cell layer comes in contact with nearly the entire blood volume throughout the spongy heart wall in this type of teleosts. Anat Rec, 294:1500Rec, 294: -1505Rec, 294: , 2011. V V C 2011 Wiley-Liss, Inc.

Goblet Cells and Mucus Types in the Digestive Intestine and Respiratory Intestine in Bronze Corydoras (Callichthyidae: Teleostei)

“…Then, the sections were treated with 1% aqueous solution of neutral red followed by 1% aqueous solutions of eosin, dehydrated through a graded ethanol series and mounted under cover slips in the mounting medium (Grimstone and Skaer, ). The number of ferritin‐injected specimens was as low as possible; the injection needle was thin; and the amount of injected ferritin was small in accordance with the established national ethical guidelines, rules and legislations for this type of experiments (Leknes, , ).…”

Blood cleansing cells in head kidney and spleen in Buenos Aires tetra, Hyphessobrycon anisitsi (Eigenmann), (Characidae: Teleostei)

“…The number of ferritin-injected specimens was kept as low as possible, the injection needles were thin, and the amount of injected ferritin was small in accordance with the established national ethical guidelines, rules and legislations for this type of experiment (Leknes 2011).…”

Scavenger endothelial cells of fish, a review

“…Heart Ferritin Leknes (2009Leknes ( , 2011Leknes ( , 2016 Buenos Aires tetra (Hyphessobrycon anisitsi)…”

“…One of the cichlid species (Thorichthys meeki) was injected intraperitoneally with horse ferritin. The endothelial cell layer of the heart atrium and ventricle displayed high ability to endocytose from the blood, but the corresponding layer in bulbus arteriosus displayed no such uptake (Leknes, 2009(Leknes, , 2011. The structure and cell types in kidney and spleen of Buenos Aires tetra, Hyphessobrycon anisitsi, family Characidae, are described (Leknes, 2012).…”