Thyroid and hypoxic stress in the newt Triturus carnifex

• Published in: Journal of experimental zoology. Part A, Comparative experimental biology Comparative experimental biology, 2006-03, Vol.305A (3), p.225-232
• Main Authors: Frangioni, Giuliano, Atzori, Antonio, Balzi, Manuela, Fuzzi, Giancarlo, Ghinassi, Andrea, Pescosolido, Nicoletta, Bianchi, Stefano, Borgioli, Gianfranco
• Format: Article
• Language: English
• Subjects: Animals; Fatty Liver - blood; Fatty Liver - metabolism; Female; Heart Rate - physiology; Histocytochemistry; Hypoxia - blood; Hypoxia - metabolism; Kidney - metabolism; Male; Melanosis - metabolism; Pituitary Gland - metabolism; Salamandridae; Salamandridae - blood; Salamandridae - metabolism; Stress, Physiological - blood; Stress, Physiological - etiology; Stress, Physiological - metabolism; Thyroid Gland - metabolism; Thyrotropin - blood; Thyroxine - blood; Triiodothyronine - blood; Triturus carnifex
• ISSN: 1548-8969; 1932-5223; 1552-499X; 1932-5231
• DOI: 10.1002/jez.a.268

When specimens of the newt Triturus carnifex, under anaesthesia by submersion in a 0.2% chlorbutol solution for 25 min, are isolated in a respiratory chamber at 18°C containing water with only 1.3 ppm of oxygen, they consume the oxygen completely in about 3 hr, but they can stay alive for many more hours and wake up with no apparent exterior consequences. Hypoxia induces rapid onset of hepatic steatosis and melanosis, as well as a controlled haemolytic process involving a pool of red blood cells of the same order of size as that held as a reserve in the spleen by animals in an aerial habitat. At the origin of the phenomena is an intense response by the hypophysis, histologically detectable 1 hr from the onset of treatment and confirmed 2 hr later by a highly significant increase in the plasma thyroidstimulating hormone (TSH) concentration compared with the controls (41.5±13.7 µU/L vs. 15.5±6.2; P