ABSTRACT
Background: Understanding of the mechanisms governing liver regeneration may be useful for designing treatments for patients with hepatitis, liver injury, or liver transplant. The aim of the present study was to investigate the ultrastructural changes and BCL-2 protein expression associated with partial hepatectomy [PHx]
Materials and Methods: This study was carried out on 30 male albino rats assigned to three experimental groups. PHx was done for all the 30 animals and liver tissues were collected to become control tissues. The rats were sacrificed in 24 h [group A], 48 h [group B], and 72 h [group C] after PHx. Liver specimens were processed for light and transmission electron microscope. BCL-2 protein expression was evaluated in all groups
Results: Hepatocytes of groups A and B showed several apoptotic changes. BCL-2 protein expression was not detected in the hepatocytes of controls. 48h after PHx, the nuclei of the hepatocytes showed abundant heterochromatin with indistinct nucleoli. The cytoplasms showed numerous electron lucent vacuoles, and swollen mitochondria compared with the controls. Moreover, dilated bile canaliculi with absent microvilli were observed. Meanwhile, 72 h after PHx, the general architecture of liver was retained nearly to normal
Conclusion: In conclusion, during the 48 h after PHx, the hepatocytes underwent proliferative and apoptotic changes followed by regaining their normal structure and organization
ABSTRACT
Background: Titanium dioxide [TiO2] is a white pigment which is used in paints, plastics, etc. It is reported that TiO2 induces oxidative stress and DNA damage. N-acetylcysteine [NAC] has been used to fight oxidative stress-induced damage in different tissues. The objective of this study was to evaluate the toxic effects of orally administered TiO2 nanoparticles and the possible protective effect of NAC on the testes of adult male albino rats
Materials and Methods: In this experimental study, 50 adult male albino rats were classified into five groups. Group I was the negative control, group II was treated with gum acacia solution, group III was treated with NAC, group IV was treated with TiO2 nanoparticles, and group V was treated with 100 mg/kg of NAC and 1200 mg/kg TiO2 nanoparticles. Total testosterone, glutathione [GSH], and serum malondialdehyde [MDA] levels were estimated. The testes were subjected to histopathological, electron microscopic examinations, and immunohistochemical detection for tumor necrosis factor [TNF]-alpha. Cells from the left testis were examined to detect the degree of DNA impairment by using the comet assay
Results: TiO2 nanoparticles induced histopathological and ultrastructure changes in the testes as well as positive TNF-alpha immunoreaction in the testicular tissue. Moreover, there was an increase in serum MDA while a decrease in testosterone and GSH levels in TiO2 nanoparticles-treated group. TiO2 resulted in DNA damage. Administration of NAC to TiO2- treated rats led to improvement of the previous parameters with modest protective effects against DNA damage
Conclusion: TiO2-induced damage to the testes was mediated by oxidative stress. Notably, administration of NAC protected against TiO2's damaging effects