Ozaki Y, Wurtman R J, Alonso R, Lynch H J
Proc Natl Acad Sci U S A. 1978 Jan;75(1):531-4. doi: 10.1073/pnas.75.1.531.
Urine was collected from rats during 12 consecutive daily dark periods and assayed for melatonin and norepinephrine; the phase of the vaginal estrous cycle associated with each urine sample was determined from daily vaginal smears. The proestrous phase of the estrous cycle was consistently associated with significant reductions in the excretions of both compounds. The level of melatonin in any urine sample tended to vary as a function of its norepinephrine content; however, the slope of the curve relating these two compounds in metestrous-diestrous samples differed from that for proestrous-estrous specimens. This difference suggests that factors other than the catecholamine (e.g., gonadal hormones) also affect melatonin secretion. Oophorectomy elevated the melatonin concentration of serum but not that of the pineal; this rise was suppressed by the administration of estrogen plus progesterone. The fate of circulating melatonin (as indicated by the proportion of an exogenous dose excreted into the urine) was not affected by the state of the estrous cycle.
在连续12个每日黑暗期内从大鼠收集尿液，并检测褪黑素和去甲肾上腺素；根据每日阴道涂片确定与每个尿液样本相关的阴道发情周期阶段。发情周期的动情前期始终与这两种化合物排泄量的显著减少相关。任何尿液样本中褪黑素的水平往往随其去甲肾上腺素含量而变化；然而，在动情后期-间情期样本中，这两种化合物之间关系曲线的斜率与动情前期-发情期样本的不同。这种差异表明，除儿茶酚胺（如性腺激素）外的其他因素也会影响褪黑素的分泌。卵巢切除提高了血清中褪黑素的浓度，但未提高松果体中的浓度；雌激素加孕酮的给药可抑制这种升高。循环褪黑素的命运（如通过排泄到尿液中的外源性剂量比例所示）不受发情周期状态的影响。
