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Updated: Jul 16, 2026

In vivo Characterization of Endocrine Disrupting Chemical Effects via Thyroid Hormone Action Indicator Mouse
Published on: October 6, 2023
Thyroid responses to altered photoperiod in the soft-shelled turtle Lissemys punctata punctata bonnoterre
Supriti Sarkar1, Amita Sengupta, Santasri Chaudhuri-Sengupta
1Histophysiology Laboratory, Department of Zoology, University of Calcutta 35 Ballygunge Circular Road, Calcutta 700 019, India.
Abstract:
The aim of the current investigation was to investigate the effect of photoperiod on thyroid activity in soft-shelled turtles (Lissemys punctata punctata). Thirty days exposure of short photoperiod with 2L:22D increased relative weight, follicular epithelial height and peroxidase activity of the thyroid gland; whereas exposure of long photoperiod with 22L:2D for 30 days showed reversed changes to those of the short photoperiod in adult female turtles. These findings indicate that short photoperiod stimulates thyroid activity and long photoperiod inhibits its activity in soft-shelled turtles. It is suggested that photoperiod exerts its action on thyroid activity presumably via gonads and/or pineal-gonadal axis in turtles.
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