Interrenal responses to high ambient temperature in soft-shelled turtle, Lissemys punctata punctata.

An exposure to ambient temperature of 25 degrees C had no perceptible effect on interrenal function but further increase of temperature to 35 degrees C caused nuclear hypertrophy with increase of nuclear diameter, RNA concentration, acid phosphatase and alkaline phosphatase activities, accompanied by quantitative depletions of cholesterol (free, esterified and total) and ascorbic acid levels in the interrenal gland of the soft-shelled turtle Lissemys p. punctata. Similar manifestations of stimulation, except in the nucleus, were marked after exposure to 38 degrees C, but the degree of response in respect of esterified and free cholesterol levels was higher at 38 degrees C than at 35 degrees C. Moreover, withdrawal of 38 degrees C temperature and subsequently maintaining at 25 degrees C for 15 days showed reverse manifestations to those of 35 degrees C/38 degrees C, leading to a tendency towards normalcy. It is suggested that high a ambient temperature of 35 degrees C significantly stimulates interrenal function of Lissemys turtles, but further increase of 38 degrees C does not cause further overall stimulation, and withdrawal of higher temperature (38 degrees C) shows a tendency towards normalcy. It is also suggested that (a) high ambient temperature causes thermal stress, (b) it is reversible and (c) it acts on interrenal activity presumably via CRF-ACTH-axis in turtles.

Ray PP ，Maiti BR 《INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY》

Gonadotropins and sex hormones modulate interrenal function in soft-shelled turtle.

Ray PP ，Maiti BR 《FOLIA BIOLOGICA-KRAKOW》

Adrenomedullary hormonal and glycemic responses to high ambient temperature in the soft-shelled turtle, Lissemys punctata punctata.

The aim of the investigation was to study the influence of high ambient temperature on adrenomedullary activity and blood glucose levels in adult female soft-shelled turtles (Lissemys punctata punctata). Experiments were carried out at 25 degrees, 35 degrees, and 38 degrees, and one group was exposed to 38 degrees for 15 days and then maintained at 25 degrees for another 15 days. Exposure to a low ambient temperature of 25 degrees had no clear effect on adrenomedullary function with respect to histology (nuclear diameter), epinephrine and norepinephrine concentrations, and blood glucose level of turtles, but higher temperatures of 35 degrees and 38 degrees stimulated adrenomedullary activity as well as blood glucose level in turtles compared with controls (30 degrees ). The extent of these changes was greater at 38 degrees than that at 35 degrees, and withdrawal from high ambient temperature reversed the effect in turtles.

Ray PP ，Maiti BR 《GENERAL AND COMPARATIVE ENDOCRINOLOGY》

Thyroidal modulation following hypo- and hyper-thermia in the soft-shelled turtle Lissemys punctata punctata Bonnoterre.

The aim of the current study was to investigate the effects of ambient temperature on thyroid activity of the soft-shelled turtle (Lissemys punctata pucntata). Turtles exposed to low ambient temperature (10 degrees C for 15 days) showed a significant decrease in relative thyroid weight, follicular cell size (cell became squamous from cuboidal type) and epithelial height in both the peripheral and central follicles of the gland, with the appearance of homogeneous colloid materials in the follicular lumen. Thyroid peroxidase activity declined significantly. In contrast, high ambient temperatures (32/34 degrees C for 15 days) caused reverse changes to those observed after exposure with low ambient temperature. No significant difference was marked in thyroid activity between 32 and 34 degrees C temperature treatments. The findings provide evidence that low ambient temperature inhibits thyroid activity and high ambient temperature stimulates the gland activity in soft-shelled turtles. Ambient temperature acts presumably via the hypothalamo-hypophysial (TRF-TSH) axis which in turn alters thyroid function in turtles.

Sengupta A ，Ray PP ，Chaudhuri-Sengupta S ，Maiti BR ... -  《-》

Adrenocortical involvement during diverse stress in soft-shelled turtle Lissemys p. punctata Bonnoterre.

Ray PP ，Chaudhuri-Sengupta S ，Maiti BR 《INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY》