In vivo assessment of microcystin-LR-induced hepatotoxicity in the rat using proton nuclear magnetic resonance (H-1-NMR) imaging

Microcystin-LR (MCLR)-induced hepatotoxicity was assessed in vivo in male S prague-Dawley rats (150-350 g) using magnetic resonance imaging (MRI). Foll owing the intraperitoneal administration of MCLR (LD50), a region of damage , characterised by increased signal intensity on T-2-weighted images, was s een proximal to the hepatic portal vein in the liver. Similarly, increased signal intensity was seen in the chemical-shift selective images (CSSI) of water frequency, proximal to the hepatic portal vein in the liver. This ind icates that the increased signal intensity observed in the T-2-weighted ima ges was due to an increased amount of magnetic resonance (MR) visible proto ns in the tissue which represents an oedematous response. Image analysis of regions of apparent damage around the hepatic portal vein indicated a stat istically significant increase in signal intensity in this region. Mitochon drial swelling and lipid inclusions were observed by transmission electron microscopy (TEM) in samples obtained from the oedematous regions of the liv er using spatial coordinates from the magnetic resonance (MR) images. Massi ve haemorrhagic necrosis and nuclear swelling were observed by light micros copy in the centrilobular regions of the lobules. (C) 1999 Elsevier Science B.V. All rights reserved.