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Indian Journal of Experimental Biology (IJEB) >
IJEB Vol.50 [2012] >
IJEB Vol.50(06) [June 2012] >
| Title: | Effects of glucocorticoids on plasma levels of thyroid hormones (T4 and T3) and testicular activity in catfish, Clarias gariepinus during different phases of annual breeding cycle |
| Authors: | Suchiang, P
Varkey, S
Gupta, B B P |
| Keywords: | Breeding phase
Corticosteroids
Fish
Testis
Thyroid hormones |
| Issue Date: | Jun-2012 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Effects of short-term administration of
corticosterone and cortisol on plasma levels of thyroid hormones,
gonado-somatic index and testicular histology have been reported in catfish, Clarias gariepinus during different
phases of its breeding cycle. Corticosterone administration had no significant
effect on plasma levels of T4, T3 and T3/T4
ratio, irrespective of doses and phases of breeding cycle. However, 5 µg dose
of cortisol significantly increased plasma levels of T3 and the T3/T4
ratio during quiescent and regressive phases, while it significantly decreased
plasma levels of T4 during progressive phase. During breeding phase,
2 µg and 5 µg doses of cortisol significantly decreased plasma levels of T4
and T3, respectively, while 5 µg dose of cortisol alone reduced T3/T4
ratio. Irrespective of phases of annual breeding cycle and doses, short-term
administration of corticosterone and cortisol had no significant effect either
on GSI or testicular histology. These findings suggest that corticosterone is
ineffective in stimulating plasma levels of thyroid hormones, while cortisol,
depending on dose and phase/season, may differentially increase, decrease or
have no effect on plasma levels of thyroid hormones in
C. gariepinus. |
| Page(s): | 398-403 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-1009 (Online); 0019-5189 (Print) |
| Source: | IJEB Vol.50(06) [June 2012]
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