Ringberg T
Acta Physiol Scand. 1979 Mar;105(3):268-73. doi: 10.1111/j.1748-1716.1979.tb06341.x.
Seasonal changes in serum levels of growth hormone, cortisol and thyroxine in calves and adult Spitzbergen reindeer (Rangifer tarandus platyrynchus) were measured and compared to those previously found in Norwegian reindeer (R.t. tarandus). Cortisol did not differ significantly between summer and winter, or between the subspecies. Growth hormone and thyroxine exhibited highly significant seasonal changes and subspecific differences: winter levels of growth hormone were much higher than summer levels in the Spitzbergen reindeer, while Norwegian reindeer differed very little from season to season. Both Spitzbergen and Norwegian reindeer had markedly reduced thyroxine levels during winter, but the values from the former were much lower than those from the latter. In summer, however, the levels were equal. The high levels of growth hormone and low levels of thyroxine in the Spitzbergen reindeer during winter are indicative of high lipolytic activity and a reduced metabolic rate, respectively.
对小牛和成年斯匹次卑尔根驯鹿（Rangifer tarandus platyrynchus）血清中生长激素、皮质醇和甲状腺素的季节性变化进行了测量，并与之前在挪威驯鹿（R.t. tarandus）中发现的情况进行了比较。皮质醇在夏季和冬季之间，或在两个亚种之间没有显著差异。生长激素和甲状腺素表现出高度显著的季节性变化和亚种间差异：斯匹次卑尔根驯鹿冬季的生长激素水平远高于夏季，而挪威驯鹿的季节差异很小。斯匹次卑尔根驯鹿和挪威驯鹿在冬季的甲状腺素水平均显著降低，但前者的值远低于后者。然而，在夏季，两者水平相当。斯匹次卑尔根驯鹿在冬季生长激素水平高而甲状腺素水平低，分别表明其具有高脂肪分解活性和降低的代谢率。
