Author/Editor     Repež, Andrej; Giacomelli, Valentina Otja
Title     Vloga mikrocistinov pri razvoju bolezni parenhimskih organov
Translated title     The role of microcystins in the development of parenchymal disorders
Type     članek
Source     Med Razgl
Vol. and No.     Letnik 37, št. 4
Publication year     1998
Volume     str. 457-81
Language     slo
Abstract     Microcystins damage liver tissue by disorganizing the cytoskeleton and inhibiting serine threonine protein phosphatases. Liver cells shrink and blood penetrates the liver tissue. Internal bleeding may lead to haemorrhagic shock. Water pollution associated with the blooming of toxic cianobacteria as a result of intensive agriculture has been well-documented in the north-eastern Slovenia. We undertook to develop a method for isolation of hepatocytes, and to assess the potency of microcystin RR isolated from the polluted water in Slovenia. By acute exposure of rats to a mixture of microcystins RR and LR we wanted to ascertain whether internal bleeding reflects changes in the haematocrit cound. Morphological changes following chronic exposure of animals to microcystin mixture were studied. Simultaneously, we tested the hypothesis that magnetic resonance (MR) imaging is a suitable technique for assessing acute and chronic toxicity of microcystins. The experiments were performed on 37 male Wistar rats. Twenty animals were sacrificed during acute experiments. The effects of the chosen toxin on the isolated hepatocytes obtained by in situ perfusion technique were tested in half the animals, while in another half the toxin in half the animals, while in another half the toxin mixture effects were assessed in vivo using MR imaging. For chronic tests the animals were fed with microcystins for two months. Blood was drawn from the inferior caval vein for complete blood count and serum analysis. The liver was removed and weighed and liver specimens were obtained for histological examination. The hepatocyte isolation method afforded a 83% cell survival.(Abstract truncated at 2000 characters)
Summary     Microcistini prizadanejo jetrno tkivo z delovanjem na sestavine citoskeleta in ostale celične procese hepatocitov z inhibicijo serin/treonin beljakovinskih fosfataz. Parenhimske jetrne celice se skrčijo in ločijo med seboj. Razmaknejo se tudi endotelijske celice jetrnih sinusoidov in kri uhaja v jetrno tkivo. Notranja krvavitev lahko vodi v hipovolemični šok. Onesnaženost voda s cvetenji toksičnih cianobakterij je resen problem tudi v severovzhodni Sloveniji, kjer intenzivno kmetijstvo povzroča visoko stopnjo evtrofikacije voda. O akutni človeški zastrupitvi s smrtnim izidom še niso poročali. Pri ljudeh je pomembnejša kronična izpostavljenost subletalnim odmerkom toksinov. Z vpeljavo metode izolacije hepatocitov sva preverila primerljivost učinkov izbranega toksina z opisi v literaturi. V raziskavi sva ugotavljala, ali se bodo v akutnem poskusi in vivo pokazale spremembe v krvnih parametrih kot posledica krvavitve, kakšne so spremembe na jetrnih izvidih in jetrni morfologiji pri kroničnem napajanju podgan z vodo, onesnaženo z mikrocistini LR in RR. Preverila sva, ali je slikanje z magnetno resonanco ustrezna metoda za zasledovanje akutnih in kroničnih sprememb jetrnega parenhima po delovanju zmesi mikrocistinov. Znanosti sva žrtvovala 37 poskusnih živali. Za izolacijo hepatocitov s perfuzijo jeter in situ sva žrtvovala 10 poskusnih živalih. Z magnetno resonanco sva ugotavljala akutne učinke zmesi mikrocistinov na skupini 10 poskusnih živali. V kroničnem poskusu sva 12 poskusnih živali izpostavljala subletalnim odmerkom zmesi mikrocistinov v pitni vodi in v tem času dvakrat slikala jetra z magnetno resonanco. Spremembe sva po končanem poskusu ugotavljala s pregledom krvne slike, biokemičnimi testi seruma, jetrnimi testi, s tehtanjem jeter in histološkim pregledom jetrnega tkiva.(Izvleček prekinjen pri 2000 znakih.)
Descriptors     LIVER
BACTERIAL TOXINS
CYANOBACTERIA
WATER POLLUTION
MAGNETIC RESONANCE IMAGING
HISTOLOGY, COMPARATIVE
RATS, WISTAR
BLOOD CHEMICAL ANALYSIS
SLOVENIA
CYTOSKELETON
PROTEIN-SERINE-THREONINE KINASES