Peschle C, Rappaport I A, Magli M C, Marone G, Lettieri F, Cillo C, Gordon A S
Blood. 1978 Jun;51(6):1117-24.
Hypophysectomized or sham-operated male rats were exposed to hypoxia (0.42--0.40 or 0.37--0.35 atm for 6, 12, or 24 hr) applied 2 wk to 7 mo after surgery. Erythropoietin (Ep) levels in rat serum were evaluated on the basis of the exhypoxic polycythemic mouse assay. Ep activity evoked by hypoxia was significantly lower in hypophysectomized rats than in sham-operated controls. Progressive increase of the EP response to hypoxia correlated with extension of the time interval between hypophysectomy and hypoxia from 2 wk to 2--4 mo apparently mediated by the simultaneous inverse decline of red cell mass (RCM) values, i.e., of the "relative plethora" induced by a low O2 demand associated with relatively high RCM values. However, after 3--7 mo hypoxic Ep activity was still lower than in sham-operated controls. In these ablated animals the relative plethora became negligible or absent; accordingly, the Ep response apparently had reached plateau levels. These studies indicate that hypophysis (hypophyseal and target hormones, with the exception of estrogens) modulates Ep production under hypoxic conditions, possibly via a permissive enhancement of renal Ep activity.
将垂体切除或假手术的雄性大鼠在手术后2周~7个月暴露于低氧环境（0.42 - 0.40或0.37 - 0.35个大气压，持续6、12或24小时）。根据低氧后红细胞增多的小鼠试验评估大鼠血清中的促红细胞生成素（Ep）水平。垂体切除的大鼠中，低氧诱发的Ep活性显著低于假手术对照组。对低氧的Ep反应逐渐增加，这与垂体切除和低氧之间的时间间隔从2周延长至2 - 4个月相关，这显然是由红细胞量（RCM）值同时反向下降介导的，即由与相对较高的RCM值相关的低氧需求诱导的“相对多血质”。然而，3 - 7个月后，低氧Ep活性仍低于假手术对照组。在这些切除垂体的动物中，相对多血质变得微不足道或不存在；因此，Ep反应显然已达到平台期水平。这些研究表明，垂体（垂体及靶激素，但雌激素除外）可能通过对肾脏Ep活性的允许性增强，在低氧条件下调节Ep的产生。
