Ge. Bentley et Rhc. Bonser, LONG-TERM HYPOTHYROIDISM CAUSES DECREASED BONE COMPETENCE IN MALE EUROPEAN STARLINGS, STURNUS-VULGARIS, The Journal of experimental zoology, 281(6), 1998, pp. 602-607
Male European starlings were thyroidectomised and held on either short
or long day photoperiods. Intact euthyroid control birds were also he
ld on either short or long days to control for differences in reproduc
tive condition. Femora of birds from each group were sampled following
plasma thyroxine measurement. Hypothyroidism caused decreased bone me
chanical competence in starlings, as determined by Vickers microhardne
ss testing. It was also found that transfer from short to long dayleng
ths caused increased plasma thyroxine concentration, but that this did
not affect bone mechanical competence. The finding that hypothyroidis
m causes decreased bone mechanical competence agrees with another anim
al study and a number of human studies, and we conclude that bone qual
ity and mechanical competence can be adversely affected by abnormal th
yroxine concentrations. (C) 1998 Wiley-Liss, Inc.