Abstract
In vivo visualization of kidney and liver damage by Magnetic Resonance Imaging (MRI) may offer an advantage when there is a need for a simple, non-invasive and rapid method for screening of the effects of potential nephrotoxic and hepatotoxic substances in chronic experiments. Here, we used MRI for monitoring chronic intoxication with microcystins (MCs) in rat. Male adult Wistar rats were treated every other day for eight months, either with MC-LR (10 μg/kg i.p.) or MC-YR (10 μg/kg i.p.). Control groups were treated with vehicle solutions. T1-weighted MR-images were acquired before and at the end of the eight months experimental period. Kidney injury induced by the MCs presented with the increased intensity of T1-weighted MR-signal of the kidneys and liver as compared to these organs from the control animals treated for eight months, either with the vehicle solution or with saline. The intensification of the T1-weighted MR-signal correlated with the increased volume density of heavily injured tubuli (R2 = 0.77), with heavily damaged glomeruli (R2 = 0.84) and with volume density of connective tissue (R2 = 0.72). The changes in the MR signal intensity probably reflect the presence of an abundant proteinaceous material within the dilated nephrons and proliferation of the connective tissue. T1-weighted MRI-is a valuable method for the in vivo screening of kidney and liver damage in rat models of intoxication with hepatotoxic and nephrotoxic agents, such as microcystins.
Highlights
Microcystin-LR (MC-LR) and microcystin-YR (MC-YR) are toxic monocyclic heptapeptides characterized by the presence of an unusual amino acid,3-amino-9-methoxy-2,6, 8-trimethyl-10-phenyldeca-4,6-diene acid ADDA, in their structure
The imaging revealed an increase in signal intensity proximal to the hepatic portal vein, but there is no data on the effects of chronic exposure to MCs [39]
Histological analysis showed that changes seen on magnetic resonance (MR) images represented liver injury characterized with fatty infiltration and periportal fibrosis
Summary
Microcystin-LR (MC-LR) and microcystin-YR (MC-YR) are toxic monocyclic heptapeptides characterized by the presence of an unusual amino acid, (all-S,all-E)-3-amino-9-methoxy-2,6, 8-trimethyl-10-phenyldeca-4,6-diene acid ADDA, in their structure They are produced by some species of cyanobacteria, found in both freshwater and in the marine environment [1,2,3,4]. The uptake of MCs into the cells occurs via the specific bile acid carriers These carriers are present in several cell types, especially in liver, ileum, kidney and brain [9,10,11,12]. Histopathological findings in animals after chronic application of MCs revealed that kidneys were more affected than liver. Signal intensity form T1-weighted images was correlated to the volume density of injured tubules, the volume density of connective tissue and the percentage of heavily damaged renal corpuscles
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call