Identification and properties of sex steroid binding proteins in nesting Chelonia mydas plasma

Ikonomopoulou, M. P., Bradley, A. J., Whittier J. M. and Ibrahim, K. (2005). Identification and properties of sex steroid binding proteins in nesting Chelonia mydas plasma. In: ANZSCPB Proceedings. ANZSCPB 2005: 22nd Annual Meeting of the Australian and New Zealand Society for Comparative Physiology and Biochemistry, Dunedin, Otago, N.Z., (). 9-11 December 2005.


Author Ikonomopoulou, M. P.
Bradley, A. J.
Whittier J. M.
Ibrahim, K.
Title of paper Identification and properties of sex steroid binding proteins in nesting Chelonia mydas plasma
Formatted title
Identification and properties of sex steroid binding proteins in nesting Chelonia mydas plasma
Conference name ANZSCPB 2005: 22nd Annual Meeting of the Australian and New Zealand Society for Comparative Physiology and Biochemistry
Conference location Dunedin, Otago, N.Z.
Conference dates 9-11 December 2005
Proceedings title ANZSCPB Proceedings
Place of Publication Dunedin, NZ
Publisher Australian & New Zealand Society for Comparative Physiology & Biochemistry
Publication Year 2005
Sub-type Poster
ISBN 9780473107192
0473107198
Volume 22
Language eng
Formatted Abstract/Summary
The presence of a sex steroid binding protein in the plasma of sea turtles has not previously been studied. The information presented on steroid-protein interactions in this study provides an insight into the reproductive status of sea turtles. A sex high-affinity, low-capacity sex hormone steroid binding protein was identified in nesting Chelonia mydas and its thermal profile was established. At 4°C testosterone and oestradiol bind in nesting Chelonia mydas with high affinity (Kd = 1.39 x 10-8 M; 1.89 x 10-7 M) and low binding capacity (Bmax = 4.08 x 10-5 M; 3.90 x 10-5 M), respectively. At 23°C the binding affinity and capacity of testosterone and oestradiol were similar with those determined at 4°C (Kd = 1.8 x 10-8 M; 1.9 x 10-7 M) and (Bmax = 1.9 x 10-5 M; 8.3 X 10-5 M), respectively. At 36°C testosterone maintained its binding affinity and capacity with those of at 4°C and 23°C (Kd = 1.2 x 10-8 M) and (Bmax = 4.9 x 10-5 M), respectively however, oestradiol showed no binding activity at 36°C. The results of this study indicate that temperature has minimal effect on the high affinity binding of testosterone to sex steroid binding protein but the high affinity binding of oestradiol to sex steroid binding protein is abolished at a hypothetical high (36°C) body temperature. This suggests that at high core body temperatures most of the oestradiol would become biologically available to the tissues rather than a large percentage of the total hormone remaining inactive in the plasma.
Subjects 1199 Other Medical and Health Sciences
Q-Index Code EX
Q-Index Status Provisional Code
Institutional Status Unknown
Additional Notes Presented during Session 8: "Global Science Poster Session" as Abstract 36.

 
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Created: Wed, 05 May 2010, 15:12:18 EST by Jon Swabey on behalf of Faculty Of Health Sciences