title: Alterations in the skin of Labeo rohita exposed to an azo dye, Eriochrome black T: a histopathological and enzyme biochemical investigation.
abstract: Histopathological changes and alterations in the activity of certain metabolic and antioxidant enzymes were analyzed in the head skin of Labeo rohita, exposed to sublethal test concentrations of the azo dye, Eriochrome black T for 4 days, using 24 h renewal bioassay method. Hypertrophied epithelial cells, increased density of mucous goblet cells, and profuse mucous secretion at the surface were considered to protect the skin from toxic impact of the azo dye. Degenerative changes including vacuolization, shrinkage, decrease in dimension, and density of club cells with simultaneous release of their contents in the intercellular spaces were associated to plug them, preventing indiscriminate entry of foreign matter. On exposure of fish to the dye, significant decline in the activity of enzymes-alkaline phosphatase, acid phosphatase, carboxylesterase, succinate dehydrogenase, catalase, and peroxidase-was associated with the binding of dye to the enzymes. Gradual increase in the activity of lactate dehydrogenase was considered to reflect a shift from aerobic to anaerobic metabolism. On transfer of azo dye exposed fish to freshwater, skin gradually recovers and, by 8 days, density and area of mucous goblet cells, club cells, and activity of the enzymes appear similar to that of controls. Alteration in histopathology and enzyme activity could be considered beneficial tool in monitoring environmental toxicity, valuable in the sustenance of fish populations.
authors.affiliation: Skin Physiology Laboratory, Centre of Advanced Study, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India.
authors.forename: Ayan
authors.initials: A
authors.lastname: Srivastava
authors.affiliation: Skin Physiology Laboratory, Centre of Advanced Study, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Verma
authors.affiliation: Skin Physiology Laboratory, Centre of Advanced Study, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India.
authors.forename: Arup
authors.initials: A
authors.lastname: Mistri
authors.affiliation: Skin Physiology Laboratory, Centre of Advanced Study, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India.
authors.forename: Brijesh
authors.initials: B
authors.lastname: Ranjan
authors.affiliation: Skin Physiology Laboratory, Centre of Advanced Study, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India.
authors.forename: Ashwini Kumar
authors.initials: AK
authors.lastname: Nigam
authors.affiliation: Zoology Section, Mahila Mahavidyalaya, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India.
authors.forename: Usha
authors.initials: U
authors.lastname: Kumari
authors.affiliation: Skin Physiology Laboratory, Centre of Advanced Study, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India. drsmittal73@gmail.com.
authors.forename: Swati
authors.initials: S
authors.lastname: Mittal
authors.affiliation: Department of Zoology, Banaras Hindu University, 9, Mani Nagar, Kandawa, Near Chitaipur Crossing, Varanasi, 221106, Uttar Pradesh, India.
authors.forename: Ajay Kumar
authors.initials: AK
authors.lastname: Mittal
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001391:Azo Compounds / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D004396:Coloring Agents / Q000633:toxicity*; D003530:Cyprinidae / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D012867:Skin / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D013385:Succinate Dehydrogenase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D001391:Azo Compounds; D004396:Coloring Agents; D014874:Water Pollutants, Chemical; D002374:Catalase; D013385:Succinate Dehydrogenase; C014527:Eriochrome Black T
keywords: Eriochrome black T; Histopathology; Labeo rohita; Metabolic and antioxidant enzymes; Skin