Carbofuran-induced histophysiological changes in thyroid of the teleost fish, Channa punctatus (Bloch)
The long-term toxic effects of continuous exposure for 6 months, from January to June, to a safe dose (4.5 ppm) of a commercial carbamate pesticide, carbofuran, on the histophysiology of thyroid in adult and young (yearling) Channa punctatus, are described in this investigation. In both the experimental groups, thyroid histology exhibited various abnormalities, including hypertrophy, hyperplasia and degeneration of follicular epithelial cells, and reduction in colloid content. Apart from this, in young experimentals, fibrosis of thyroid components, formation of cystic cellular masses, and rupture of blood vessels resulting in hemorrhage can also be seen and suggest direct action of this pesticide on the thyroid. On the other hand, in both treated groups, retardation of thyroid function was also evidenced by significantly reduced thyroidal radioiodine (/sup 131/I) uptake and CR (conversion ratio of PB/sup 131/I in blood serum in relation to total serum /sup 131/I uptake) values. Apparently, these histopathological and physiological changes were markedly pronounced in young experimentals, suggesting greater susceptibility of this group to chronic toxicity of carbofuran than that of adults. Thus, on the basis of these results, it can be inferred that carbofuran pesticide, which is washed into water systems in small quantities, induces adverse histophysiological alterations in thyroid, in an age- and size-dependent manner, possibly by acting directly on thyroid and/or through the hypothalamo-pituitary-thyroid axis, in this species.
- Research Organization:
- Banaras Hindu Univ., Varanasi (India)
- OSTI ID:
- 6145932
- Journal Information:
- Ecotoxicol. Environ. Saf.; (United States), Vol. 16:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
FURANS
TOXICITY
THYROID
PATHOLOGICAL CHANGES
AGE DEPENDENCE
CARBAMATES
FISHES
IODINE 131
PESTICIDES
TRACER TECHNIQUES
UPTAKE
ANIMALS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBONIC ACID DERIVATIVES
CARBOXYLIC ACID SALTS
DAYS LIVING RADIOISOTOPES
ENDOCRINE GLANDS
GLANDS
HETEROCYCLIC COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
RADIOISOTOPES
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology
550501 - Metabolism- Tracer Techniques