Mitochondria-rich cells changes induced by nitrite exposure in tambaqui (Colossoma macropomum Cuvier, 1818)

Abstract

The gill mitochondria-rich cells of the juvenile Amazonian fish Colossoma macropomum were analyzed using light and scanning and transmission electron microscopy after 96 h exposure to 0.04 and 0.2 mM nitrite. Although the number of mitochondria-rich cells decreased significantly in the lamellar epithelium, no decrease was found in the interlamellar region of the gill filament. Nitrite exposure caused significant reduction on the apical surface area of individual mitochondria-rich cells (p < 0.05), with a resulting reduction of the fractional area of these cells in both the lamellar and filament epithelium. Swelling of endoplasmic reticulum cisternae, nuclear envelope and mitochondria were the main changes found in the mitochondria-rich cells. Cristae lysis and matrix vacuolization characterized the mitochondrial changes. The overall ultrastructural changes indicated cellular functional disruption caused by exposure to nitrite. The changes observed in the gill indicate that the cellular structures involved in the process of energy production become severely damaged by exposure to nitrite indicating irreversible damage conducting to cell death.

Growth performance and health of juvenile tambaqui, Colossoma macropomum , in a biofloc system at different stocking densities

“…All treatments except for BFT200 and CW200 presented nitrite mean concentrations below the limit recommended for this species according to Costa et al (2004) (LC 50-96 h = 1.82 ± 0.98 mg/L) along the experiment (Table 2). However, similarly to the ammonia pattern in BFT, nitrite presented peaks beyond the fish tolerance limit between day 11 and 31 in BFT and cumulatively in CW after day 31 (Figure 2a,b), which could have led to irreversible damage and cell death (Costa et al, 2017). Despite these peaks, their short duration indicates the effect of nitrifying bacteria specially in the BFT environment (Ebeling et al 2006), preventing fish mortality.…”

Mitochondria-Rich Cells: A Novel Type of Concealed Cell in the Small Intestine of Chinese Soft-Shelled Turtles (Pelodiscus Sinensis)

“…Mitophagy may be associated with mitochondrial fission by separating functional mitochondria from the damaged portion [39]. Additionally, after nitrite treatment, the numbers of mitochondria-rich cells decreased, and swelling of the endoplasmic reticulum and vacuolization of the mitochondria occurred inside the mitochondria-rich cells [19].…”

“…MRCs may also play an important role in acid–base regulation [17,18]. In addition, several environmental conditions, such as high temperature and high levels of organic matter, favor the occasional development of nitrite (NO 2 2− ) in the Amazonian environment and, in fish culture systems, this energetic mechanism involves NO 2 2− uptake by the MRCs in the gill [19]. MRCs in the kidney tubules and gills are the primary cells responsible for ion transport.…”

Osmoregulatory and immunological role of new canceled cells: Mitochondrial rich cells and its future perspective: A concise review

“…Amphibian (frog) skin is undoubtedly a heterogeneous epithelium, with MRCs scattered throughout the majority of the main cells in the superficial layer (Devuyst et al, 1991). Additionally, in fish culture systems, this energetic pathway involves NO22− uptake by the MRCs in the gill due to environmental conditions including high temperature and high quantities of organic matter, which favor the occasional development of nitrite (NO22−) in the Amazonian environment (Costa et al, 2017). Ion transport is primarily mediated by MRCs in the kidney tubules and gills.…”