|Project's title||Study on the effects of lead and cadmium on endocrine system and detoxification mechanism of these metals in Climbing Perch (Anabas testudineus)|
|Research hosting institution||Ho Chi Minh City Institute of Resources Geography|
|Project leader’s name||Nguyen Thi Kim Phuong|
|Project duration||01/01/2020 - 31/12/2021|
|Project’s budget||900 million VND|
|Goal and objectives of the project||
Evaluation of the accumulation of Cd, Pb and their impact on the endocrine system as well as the detoxification mechanism of these metals in Climbing Perch (Anabas testudineus)
|Main results|| |
Theoretical results: The 96 h LC50 values of Pb and Cd for A. testudineus were found to be approximately 120 and 38 mg/L, respectively. To study the accumulation of Pb and Cd in the body and assess the effects of these metals on the endocrine system, healthy A. testudineus were exposed to Pb (20, 30, and 40 mg/L) and Cd (3, 5, and 10 mg/L) for seven, 14, 21, and 28 days. The order of Pb accumulation in the tissues after exposure was gill >> liver > muscle whereas the order of Cd accumulation was liver >> gill > muscle. Endocrine dysfunction was characterized by varying the levels of cortisol, glucose, insulin plasma and liver glycogen levels. Exposure to both Pb and Cd caused a significantly increase levels of cortisol in plasma (p < 0.05), while plasma glucose levels slightly increased at the beginning and then decreased sharply. Glucose in the blood is generated from the breakdown of carbohydrates from food in the small intestine and the breakdown of stored glycogen in the liver. Liver glycogen levels in fish exposed to Pb and Cd were significantly decreased as time proceeds. Since glucose in the blood is used to provide energy for the whole body, to maintain normal plasma glucose levels during starvation, the liver acts an important role in the production of glucose through glycogenolysis and gluconeogenesis. In addition, plasma insulin levels in fish exposed to Pb and Cd were significantly reduced to depletion. Insulin depletion interferes with glycogen storage in the liver and muscle of fish. K+/Na+-ATPase is a membrane bound enzyme located mostly in osmoregulatory tissues such as gill and intestine where it maintains ionic and electrical gradients necessary for transepithelial salt movements. The decrease in K+/Na+-ATPase enzyme activity on gills of fish living in Pb and Cd could be related to high affinity of these metals to –SH groups on the enzyme molecule, membrane rupture, osmoregulation dysfunctions, or disturbance of the ion homeostasis, leading to affect some important metabolism in the organism. Organic Pb compounds are more toxic than inorganic Pb, the conversion from inorganic Pb to organic Pb in the liver and muscle of A. testudineus was relatively low. About 55% Cd in liver and 80% Cd in muscle of A. testudineus is bound to metallothionein as a protective mechanism for the body from the toxicity of Cd.
|Novelty and actuality and scientific meaningfulness of the results|| |
It has been found the order of accumulation of Pb and Cd as well as the effects of these metals on the endocrine system (pancreas, adrenal gland) of climbing perch.
|Products of the project|| |
- Scientific papers in referred journals (list): 01 on SCI-E and 01 on national journal
|Research area|| |
Aquatic and Water Quality Regulatory Authority, Aquatic Toxicologists.
|Images of project|| |