Adrenomedullary and glycemic alterations following diverse stress in soft-shelled turtles Lissemys punctata punctata Bonnoterre.

The objective of the current investigation was to study adrenomedullary and glycemic responses to stress in soft-shelled turtles, Lissemys p. punctata. Dehydration (7 days) and formalin (formaldehyde 1%, 0.1 mL/100 g body wt. daily for 7 days) stress-stimulated adrenomedullary activity at histological (by increasing the nuclear diameter and degranulation of chromaffin cells) and hormonal levels (by elevations of norepinephrine and epinephrine concentrations) with hyperglycemia in turtles. But salt loading (NaCl: 1%, 1 mL/100 g body wt. daily for 7 days) had no significant effect on adrenomedullary activity or glycemia presumably owing to the nonresponsiveness of adrenocortical activity to salt stress in turtles. It is suggested that dehydration and formalin stresses might have exerted their actions through the hypothalamo (CRF)-hypophysial (ACTH)-adrenocortical axis in turtles.

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

Adrenomedullary and glycemic responses to ACTH, corticosterone, aldosterone, epinephrine and norepinephrine administrations in the soft-shelled turtle.

The aim of the current investigation was to ascertain the role of ACTH and adrenal hormones on adrenomedullary and glycemic functions in soft-shelled turtles, Lissemys punctata punctata. All the experiments were carried out on sexually immature animals. Findings revealed that: (1) ACTH administration (0.5 IU/1.0 IU/2.0 IU per 100 g body wt. daily for 10 days) in all doses stimulated adrenomedullary function by increasing medullary cell nuclear diameter with elevations of norepinephrine, epinephrine and blood sugar levels. Only moderate and higher doses (50 microg/100 microg per 100 g body wt. daily for 10 days) of dexamethasone suppressed adrenomedullary activity and blood sugar level by reversing the changes to those of ACTH; the responses were dose-dependent. But these changes were no longer observed after ACTH treatment in dexamethasone (DMS) recipients (DMS: 100 microg/ 100 g body wt daily for the first 10 days and ACTH: 0.5 IU / 100 g body wt daily for the next 10 days); (2) Only moderate and higher doses (50 microg/100 microg per 100 g body wt daily for 10 days) of corticosterone increased adrenomedullary activity and blood sugar level and the responses were also dose-dependent. But aldosterone treatment in all doses (same as for corticosterone) had no significant effect on the adrenal medulla or blood sugar level; (3) Only moderate and higher doses of norepinephrine or epinephrine (same as for corticosterone) caused adrenomedullary atrophy with depletions of norepinephrine and epinephrine levels but elevated the glycemic level. The findings are briefly discussed.

Ray PP ，Chaudhuri-Sengupta S ，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》

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》

Thyroidal inhibition following diverse stress in soft-shelled turtle, Lissemys punctata punctata bonnoterre.

The current study was undertaken to ascertain the effects of diverse stress on thyroid activity in soft-shelled turtles, Lissemys punctata punctata. The findings revealed that starvation (10 days), dehydration (10 days) or exposure to electric shock (12 volts for 15 seconds at an interval of 30 min for 3 h) caused significant decrease in the body weight (except in electric shock), relative weight, peripheral and central epithelial heights of the follicles and peroxidase activity of the thyroid gland of turtles. The degree of change in the values of these parameters was nearly same in all the stress experiments, indicating that there is not much difference in the degree of thyroid responses to diverse stress in turtles. It is suggested that these stressors might have exerted their actions on thyroid activity presumably indirectly via adrenal medulla and/or substance in metabolic stress (starvation and dehydration) and via hypothalamo-hypophysial-adrenocortical axis in non-metabolic stress (electric shock) in Lissemys turtles.

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