Long‐lasting morphofunctional remodelling of liver parenchyma and stroma after a single exposure to low and moderate doses of cadmium in rats

Abstract

Frequent exposure to cadmium (Cd) in low doses is common; however, the long-lasting effects of this exposure are still poorly understood. Therefore in this study we have evaluated long-lasting hepatic morphofunctional adaptations in rats exposed to low and moderate doses of Cd. Five experimental groups were tested: control (0.9% saline) and other four receiving single intraperitoneal doses of 0.67, 0.74, 0.86 and 1.1 mg of Cd/kg. The animals were killed after eight weeks and the following parameters were analysed: biometrics, oedema, Cd bio-accumulation, collagen, glycogen, lipid droplets, superoxide dismutase (SOD) and catalase (CAT), serum transaminases, liver histopathology and stereology. In all groups exposed to Cd there was significant increase in SOD and CAT activities, ALP levels, proportion of binucleated hepatocytes, nuclei/cytoplasm ratio, macrophages (Kupffer cells) and collagen fibres. In these groups, glycogen accumulation by hepatocytes and the proportion of sinusoidal capillaries were significantly reduced compared with controls. The liver somatic index was increased, and liver oedema was evident in animals exposed to higher dose of Cd. Areas of necrosis were found in animals exposed to the three highest doses. These results indicate that Cd is an extremely toxic bioactive heavy metal, which even at low doses is able to disrupt liver homeostasis. At low and moderate doses, Cd exposure induces morphofunctional pathological remodelling of the hepatic stroma and parenchyma, which remain active after eight weeks. In response to injury, the liver tissue triggers a reactive process by enhancing activation of antioxidant enzymes and collagenogenesis.

Chronic exposure to cobalt compounds — an in vivo study

“…Our results for CoCl 2 are in agreement with those of Garoui et al for decreased liver weight in day 14 rats [15]. The increased LI after Co-EDTA exposure is in agreement with Cupertino et al [16] showing increased liver somatic index in rats after chronic treatment with cadmium. The results indicate that the biological effect of cobalt depends on the type of compound it forms.…”

Effect of heavy metal intoxication on macrophage metabolic activity of mice infected with Ascaris suum

“…Cd exposure induces morpho-functional pathological remodelling of the hepatic stroma and parenchyma. In response to the injury liver tissue triggers a reactive process by enhancing activation of antioxidant enzymes and collagenogenesis (Cupertino et al, 2013). Inflammatory reactions in the liver of hosts infected with Ascaris forms "white spots".…”

Chemopreventive effects of pequi oil (Caryocar brasiliense Camb.) on preneoplastic lesions in a mouse model of hepatocarcinogenesis

“…The V v that results from this equation can range from 0 to 1, although the values can also be expressed as a percentage (Novaes et al, 2012;Cupertino et al, 2013;Santos et al, 2013).…”