Environmental temperature impact on bone and cartilage growth.

摘要: Environmental temperature can have a surprising impact on extremity growth in homeotherms, but the underlying mechanisms remained elusive for over century. Limbs of animals raised at warm ambient are significantly and permanently longer than those littermates housed cooler temperature. These remarkably consistent lab results closely resemble ecogeographical tenet described by Allen's "extremity size rule," that appendage length correlates with latitude. This phenotypic plasticity could adaptive significance thermal physiology. Shortened extremities help retain body heat cold environments decreasing surface area potential loss. Homeotherms evolved complex to maintain tightly regulated internal temperatures challenging environments, including "facultative heterothermy" which limb parallel ambient. modulation tissue direct immediate consequences cell proliferation, metabolism, matrix production, mineralization cartilage. Temperature also indirectly influence cartilage modulating circulating levels delivery routes essential hormones paracrine regulators. Using an integrated approach, this article synthesizes classic studies new data shed light basis enigmatic phenomenon its relevance treating human bone elongation disorders. Discussion centers vasculature as gateway understanding interconnection between (local) indirect (systemic) temperature-enhanced lengthening. Recent advances imaging modalities enable dynamic study plates vivo will be key elucidating fundamental physiological long regulation.