The Rate of Bone Mineralization in Birds Is Directly Related to Alkaline Phosphatase Activity

Abstract

Recent studies have suggested that a biochemical marker, plasma alkaline phosphatase (ALP), can be used as a general indicator of skeletal development in vertebrate animals. In birds, age-related variation in ALP activity, presumably due to bone formation processes, has been demonstrated, but to date, a direct connection between bone mineralization and enzyme activity has been elusive. In this study, we show that the activity of a bone isoform of ALP (bone ALP) is closely related to the overall rate of skeletal mineralization in nestlings of a small passerine bird, the great tit (Parus major L). Moreover, bone ALP activity predicted the rate of mineralization of leg and wing bones but not that of the skull. Liver isoform of ALP was only marginally related to the overall rate of skeletal mineralization, while no association with the mineralization of long bones was found. We conclude that bone ALP activity in the blood plasma is a reliable biomarker for skeletal mineralization in birds. This marker enables detection of subtle developmental differences between chicks of similar structural size, potentially facilitating the prediction of offspring mid- and long-term survival.

Titanium dioxide nanoparticles enhance production of superoxide anion and alter the antioxidant system in human osteoblast cells

“…Figure S4), an enzyme participating in bone-tissue mineralization and commonly used as a marker of osteoblastic differentiation in in vitro studies. 30,31 These results are consistent with those of Hou et al 32 who showed that ALP activity was decreased in mesenchymal stem cells incubated with TiO 2 NPs.…”

Plasma alkaline phosphatase as a sensitive indicator of age and skeletal development in wild coscoroba swans

“…We expect T-ALP activity in this species to be more reflective of the longitudinal growth of bones than that in altricial and semi-precocial birds (e.g. Tilgar et al 2008a).…”

“…Recent studies have suggested that ALP may have useful applications for conservation measures (e.g. Dobado-Berrios and Ferrer 1997;Gambin et al 1999;Kuz'mina et al 2003;Grewal and Mahmood 2004;Tilgar et al 2008a).…”

“…Takenaka et al 1988;Price 1993;Hoffmann et al 1999;Allen et al 2000;de Behr et al 2003) and birds (e.g. Viñuela et al 1991;Cubo et al 2000;Tilgar et al 2004bTilgar et al , 2008a. For instance, Tilgar et al (2008b) demonstrated that, in passerine birds, bone ALP was a better indicator of nestling maturity than traditionally used morphological measures.…”

“…Viñuela et al 1991;Viñuela and Ferrer 1997;DobadoBerrios et al 1998;Seiser et al 2000;Villegas et al 2002;Tilgar et al 2004a). Further, a recent study with passerines indicated that T-ALP activity mostly reflects rapid mineralisation of long bones rather than delayed mineralisation of flat bones such as the skull (Tilgar et al 2008a). However, no comparative studies are available for precocial birds.…”