Circannual rhythms of plasma testosterone and luteinizing hormone levels in golden-mantled ground squirrels (Spermophilus lateralis).
Circannual rhythms of plasma testosterone and luteinizing hormone levels in golden-mantled ground squirrels (Spermophilus lateralis).
复制标题
金披地松鼠（Spermophilus Lateris）血浆睾酮和黄体生成素水平的周期性节律。
DOI：
10.1095/biolreprod27.2.411
复制
发表时间：
1982
影响因子：
3.6
通讯作者：
Boshes,M
中科院分区：
文献类型：
--
作者：
Licht,P;Zucker,I;Hubbard,G;Boshes,M
雄性松鼠大约在6月1日出生，从出生起就保持在恒定的光周期（每天14小时光照）和温度（23 ± 2°C）条件下，血浆睾酮（T）和黄体生成素（LH）水平表现出昼夜节律。每月采集一次血样，连续22个月，用放射免疫法测定激素水平。在第一年的10月至1月期间，睾酮水平较低或无法检测到（≤0.05 ng/ml），2月开始增加，4月和5月达到峰值（约10 ng/ml）。4.5 ng/ml）。到第二年8月，T已降至低水平，并维持至1月（0.05 ng/ml）。然后重复这个周期，第二年的4月和5月期间T滴度升高。在出生后前8个月的大部分时间内，LH水平不可检测（≤0.7 ng/ml）; 3月至7月期间，个体动物达到LH峰值。有一个密切的对应关系之间的季节性高峰和低谷的睾酮和LH。还记录了一组在类似条件下维持并连续14个月每月流血的的场诱捕雄性动物（≥11月龄）的血浆T和LH的年周期模式。在恒定条件下，血浆T和LH的节律持续11至12个月，因此有资格作为年周期。
Male squirrels, born approximately June 1 and kept under constant conditions of photoperiod (14 h of light per day) and temperature (23 ± 2°C) from birth, manifested circannual rhythms in plasma testosterone (T) and luteinizing hormone (LH) levels. Blood samples were collected once per month for 22 months and hormone levels determined by radioimmunoassay. Testosterone levels were low or undetectable (≤0.05 ng/ml) between October and January of the first year, and began increasing in February and peaked during April and May (approx. 4.5 ng/ml). By August of the second year T had declined to low levels which were maintained through January (0.05 ng/ml). The cycle then repeated, with T titers elevated during April and May of the second year. LH levels were undetectable (≤0.7 ng/ml) throughout most of the first 8 months of life; LH peaks were reached by individual animals between March and July. There was a close correspondence between seasonal peaks and troughs of testosterone and those in LH. The circannual pattern of plasma T and LH also was documented for a group of field-trapped males (≥11 months old) maintained under similar conditions and bled at monthly intervals for 14 consecutive months. Rhythms of plasma T and LH persisted with a period of 11 to 12 months under constant conditions and thus qualify as circannual cycles.