Metabolic and histopathological profile of Rattus norvegicus (Wistar) experimentally infected by Angiostrongylus cantonensis (Chen, 1935)

Abstract

Eosinophilic meningitis is a disease characterized by increased eosinophils in the cerebrospinal fluid (CSF), which is the most commonly caused by invasion of the central nervous system by helminths, as occurs in Angiostrongylus cantonensis infections. The rodent Rattus norvegicus is the definitive natural host and humans act as accidental hosts and can become infected by eating raw or undercooked snails or food contaminated with infective L3 larvae. Recently in Brazil there have been four cases of eosinophilic meningitis due to ingestion of infected Achatina fulica. To evaluate biochemical and histopathological changes caused by this parasite, R. norvegicus were experimentally infected with 100 L3 larvae of A. cantonensis. After the anesthetic procedure, serum from the rodents was collected from the inferior vena cava for evaluation of the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALKP), gamma-glutamyl transferase (GGT), total protein and its fractions. During the necropsy, the liver was collected and weighed. Then a 1-g fragment was extracted from the major lobe to quantify the hepatic glycogen and fragment remainder was taken from the same lobe and fixed in Milloning's formalin for histopathological examination. Additionally, helminths were collected from the brain and lungs of the rodents. The activities of AST, ALT, ALKP and GGT in the serum and hepatic glycogen increased in response to infection, while the levels of globulin and total protein increased only in the eighth week of infection and there was a reduction in the levels of serum glucose. Albumin and bilirubin concentrations remained stable during the experiment. Infection with A. cantonensis caused metabolic and histopathological changes in the rodents. This study can contribute to a better understanding of the relationship between A. cantonensis and R. norvegicus.

First records of molluscs naturally infected with Angiostrongylus cantonensis (Nematoda: Metastrongyloidea) in Sergipe State, Northeastern Brazil, including new global records of natural intermediate hosts

“…larvae recovered from A. fulica from the municipality of Aracaju were used to infect two specimens of Rattus norvegicus through an orogastric tube at a concentration of 50 L 3 larvae per rodent. Fifty days after infection, the animals were killed and necropsied to confirm the presence of adult A. cantonensis 22 . This procedure was carried out following the Ethics Commission on Animal Use of the Oswaldo Cruz Foundation (LW-47/14).…”

Changes in Hepatic Metabolism of Rattus norvegicus Infected to Angiostrongylus cantonensis (Nematoda) and Exposed to Glyphosate-Based Herbicide

“…Both infection by A. cantonensis and oral exposure to the herbicide Roundup ® promoted alterations in the hepatic metabolism of R. norvegicus. Garcia et al [20] observed similar results in Wistar rats infected by A. cantonensis, possibly associated with the excretion or secretion products of the larval stages and adult helminths, which can increase the permeability of the hepatocyte membrane and consequently promote the outflow of enzymes o liver-specific cells in the blood [33][34][35] can significantly increase the serum activity of ALT and AST in Mus musculus mice and R. norvegicus Wistar rats [7,36]. This could be a consequence of an increase in the lipoperoxidation process due to the strong capacity of the herbicide to stimulate the production of reactive oxygen species [5,7].…”

“…Chronic Infection (CI) caused by A. cantonensis increased the activity of ALP in the blood of rodents, suggesting cholestasis. Garcia et al [20] proposed that infection by A. cantonensis impairs bile flow and solubilization of this enzyme in hepatocyte membranes, and consequently increases serum availability [32,37]. Furthermore, it has been postulated that liver tissue damage caused by helminth infection may result in cytolysis of hepatocytes, resulting from cell membrane damage and enzyme release into the bloodstream [20].…”

“…A dry biochemical analyzer (Vitros 250 system -Ortho-Clinical/Johnson & Johnson) was used for the subsequent biochemical analyses: Aspartate Aminotransferase (AST -EC 2.6.1.1) and Alanine Aminotransferase (ALT -EC 2.6.1.2) activities; serum levels of Alkaline Phosphatase (ALP -EC 3.1.3.1); Total Bilirubin (TB) and Total Proteins (TP), including albumin; kidney function parameters (urea, uric acid, and creatinine); and blood sugar level. In addition, the hepatic glycogen concentration was evaluated at the Laboratory of Physiology of Parasite Relations of Federal University or Rio de Janeiro, following the protocol presented by Garcia et al [20].…”

“…This wide distribution is particularly due to the presence in these locations of several species of gastropod molluscs susceptible to infection and that act as intermediate hosts [17][18][19], along with the presence of synanthropic rodents (Rattus rattus Linnaeus, 1758, and Rattus norvegicus Berkenhout, 1769) as definitive host. Under experimental conditions, infection by A. cantonensis can compromise the health of animals, depending mainly on the parasite burden and the animals' immunological condition [20][21][22].…”