
%0 Journal Article
%A Saunders, M. C. 
%A Gemmell, R. T. 
%A Curlewis, J. D. 
%T Plasma concentrations of thyroxine and growth hormone in the developing marsupial bandicoot, <emph type="2">Isoodon macrourus</emph>
%J Reproduction, Fertility and Development
%D 2001/04/27
%V 12
%N 6
%P 263-267
%K 
%R https://doi.org/10.1071/RD00069
%U https://www.publish.csiro.au/paper/RD00069 
%X Plasma concentrations of thyroxine (T 4 ) and growthhormone (GH) were measured in the developing bandicoot from 21 through to 69days post partum. Thyroxine concentrations increased from 7 ng mL&#8211;1 at 21 days post partum to reach a maximum ofaround 40 ng mL &#8211;1 approximately 40 days postpartum. After this time, plasma T 4concentrations decreased until about 50 days post partum, when levels were not different fromthose in the adult (9.2 &#177; 0.7 ng mL &#8211;1 ,n&equals;10). In contrast, GH concentrations weregreatest early in pouch life, with a maximum concentration of 88.2 ng mL&#8211;1 at 24 days post partum, and thereafter declinedto adult levels (4.9 &#177; 0.9 ng mL &#8211;1 ,n= 7) by about 60 days post partum. Thetemporal relationship between T4 and GH in thedeveloping bandicoot is similar to that seen in developing eutherian mammals,but in the latter species, peak plasma T4and the declinein GH occur before or soon after parturition, whereas in the bandicoot theseevents occur more than one month post partum. This comparison betweeneutherian mammals and a marsupial indicates that the timing of these endocrinechanges correlates with key developmental or maturational changes rather thanthe time of parturition. 
