Impact of heavy metals contamination on biology, biochemical, and histology of Eobania vermiculata and Monacha obstructa

Metals and metallothionein evolution in snails: a contribution to the concept of metal-specific functionality from an animal model group

“…Besides a digestive sorting organ (the stomach), all snails have a midgut gland (also called hepatopancreas or digestive gland) as their main absorption and metabolic organ (Salvini-Plawen 1988 ; Haszprunar 2009 ), producing digestive enzymes and absorbing nutrients. Minerals and carbohydrates are also stored in this organ, and especially metallic trace elements are sequestered and detoxified in certain midgut gland cells (Dallinger and Wieser 1984 ; Dallinger 1993 ; Brooks and White 1995 ; Włostowski et al 2014 ; El Mageed et al 2023 ). Interestingly, however, the cellular pathways and biochemical fates of the three metals Zn, Cu and Cd in this organ show remarkable metal-specific differences, with different ratios of their involvement in the composition and metabolism of MT isoforms (Dallinger et al 1997 ; Bebianno et al 2003 ; Höckner et al 2011a , b ; Dvorak et al 2019a , 2019b ).…”

“…Its detoxification in the snail’s tissues occurs mainly in the midgut gland and goes hand in hand with strong metal accumulation in the midgut gland cells. In gastropods, the midgut gland consists mainly of two to three cell types, called digestive cells, basophilic cells or calcium cells, and excretory or thin cells (Triebskorn and Köhler 1996 ; Marigómez et al 1998 ; Dallinger et al 2001a ; Lopes et al 2001 ; Chabicovsky et al 2004 ; Mohammadein et al 2013 ; Mleiki et al 2018 ; El Mageed et al 2023 ). These cells form a monolayer epithelium which delimits the finely branched tubules that run through the midgut gland and open into the alimentary tract via the paired midgut gland ducts (Lobo-da-Cunha 2019 ).…”