The effect of exposure to lead on histopathological changes in the rat liver and kidney in relation to age

Promatrane su patohistološke promjene jetre i bubrega u odraslih ženki štakora i u njihove mladunčadi iz dvaju rasploda nakon oralne izloženosti olovu (acetat) u koncentraciji od 7500 ppm u vodi za piće. Izloženost je trajala do ukupno 20 tjedana. Reverzibilnost ovih promjena procjenjivana je u skupini tzv. oporavljenih ženki kojima je prekinuto izlaganje olovu 5 tjedana prije drugog parenja s neizloženim mužjacima. U skupini izloženih odraslih ženki, kao i u skupinama njihove mladunčadi iz prvog (kraća izloženost) i drugog potomstva (duža izloženost), nađene su istovjetne patohistološke promjene u parenhimnim organima. Tako su u obih opažene masna i/ili hidropska degeneracija u jetri i bubrezima, te hemosideroza jetre. U preparatima jetre izložene mladunčadi opažena su također brojna i krupna ekstramedularna krvotvorna žarišta. U bubrezima izloženih ženki viđene su i izraženije nespecifične kronične upalne promjene. U skupinama oporavljenih ženki, nakon prekida oralne izloženosti olovu, patohistološki nalazi upućivali su na reverzibilnost morfoloških promjena. U njihove „oporavljene“ mladunčadi viđeni su gotovo uredni nalazi. Može se zaključiti da je mladunčad štakora osjetljivija od svojih majki na štetno djelovanje olova budući da su u njih opažene patohistološke promjene jetre i bubrega bile istovjetne onima u odraslih ženki, premda su bili izloženi tijekom mnogo kraćeg perioda i samo maloj frakciji ukupnog unosa olova u organizam majke.Histopathological alterations in the liver and kidneys were examined in adult female rats and in their offspring form two matings after oral exposure to 7500 ppm lead (acetate) in drinking water. The length of exposure was up to 20 weeks. To estimate the reversibility of the effects in a number of exposed females lead administration was discontinued five weeks before their second breeding with unexposed males (the recovered group). In the group of exposed adult females histopathological changes in parenchymal organs were analogous to those seen in their pups from the first (shorter exposure), and second offspring (longer exposure to lead). Fatty and/or hydropic degenerative changes in the liver and kidneys and haemosiderosis of the liver were observed in both adult females and their young. In the liver of exposed pups the presence of numerous large foci of extramedullary erythropoiesis was also detected. In the kidneys of exposed adult females non-specific chronic inflammatory changes were seen. In the group of recovered females, after discontinuation of oral exposure to lead, histopathological findings indicated the reversibility of morphological changes. In their “recovered” pups the findings were also almost normal. It may be concluded that young rats are more susceptible to adverse action of lead than their mothers. The histopathological changes observed in their livers and kidneys were analogous to those seen in adult females, although they had been exposed to lead for a much shorter period and to only a small fraction of the total mother\u27s lead intake