Journal of Endocrinology and Reproduction

Valsa S. Peter ¹, Elizabeth K. Joshua ¹, M. C. Subhash Peter ¹

Affiliations
1 Department of Zoology, University of Kerala, Kariavattom 695 581, Thiruvananthapuram, Kerala, IN

Abstract

The bark and seed of Derris plant have been used by fishermen to capture fishes, as they contain a toxic compound, rotenone, which can intoxicate fishes. In the present study, the effects of rotenone on the status of thyroid hormone and metabolites were tested in the air-breathing fish Anabas testudineus Bloch. Rotenone (1 and 5 mg L¹) exposure for 48 h produced significant reduction in serum T₃ and T₄ levels. Similarly, rotenone exposure reduced the serum T₃ and T₄ levels in thyroid hormone (TH)-pretreated fish, indicating the disruption of thyroid by rotenone. Rotenone exposure increased the serum glucose, triglycerides, urea and total liver protein in fish. On the contrary, significant reduction in LDH and aspartate aminotransferase activities in the liver and serum was found, though alkaline phosphate activity in the serum and liver, and alanine aminotransferase activity in the liver showed significant decline. A similar pattern of metabolite distribution and thyroid inhibition was also found in the TH-treated fish, ruling out the possibility of involvement of thyroid in rotenone-induced metabolite regulation. Overall, disruption of thyroid by rotenone was evident in this fish.

Keywords

Fish, Metabolism, Thyroid Hormones, Rotenone, Fish Poison.

Full Text

     

M. C. Subhash Peter ¹, Elizabeth K. Joshua ¹, Vijayamma Rejitha ¹, Valsa S. Peter ¹

Affiliations
1 Department of Zoology, University of Kerala, Kariavattom 695581, Thiruvananthapuram, Kerala, IN

Abstract

The action of thyroid hormones on metabolite regulation of nimbecidine-exposed climbing perch was studied to understand the role of these hormones in tolerance mechanisms of fish to nimbecidine exposure. Anabas testudineus, the climbing perch, was treated with nimbecidine, a neem-based biopesticide, at nominated concentrations (60 and 600 μgL^-1) for 48 h, with or without THs, and the levels of triiodothyronine (T₃) and thyroxine (T₄), metabolite and nucleic acid were quantified. The treatment of THs along with nimbecidine produced a different metabolite pattern. A significant rise in serum T₃ occurred in the nimbecidine-treated fish but the serum T₄ level remained unaffected. Nimbecidine exposure increased the serum triglycerides and the serum urea but the serum glucose and liver total protein, RNA and DNA remained unchanged. Significant reduction in the aspartate aminotransferase and alkaline phosphatase activities occurred in the serum and liver of nimbecidine-treated fish but the lactate dehydrogenase and alanine aminotransferase activities remained unaffected. The data indicate that TH modifies the metabolite pattern of climbing perch during its exposure to nimbecidine and, thus, suggest that TH is involved in the mechanism of stress tolerance in fish.

Keywords

Anabas testudineus, Climbing Perch, Fish, Metabolism, Neem, Nimbecidine, Thyroid.

Full Text