Farmer P K, Tyler J M, Stachura M E
Department of Medicine, Medical College of Georgia, Augusta 30912.
Mol Cell Endocrinol. 1989 Apr;62(2):253-62. doi: 10.1016/0303-7207(89)90012-9.
When previous data suggested a growth hormone-releasing factor (GRF)-sensitive branch in intracellular hormone processing, the monensin-sensitive Golgi apparatus seemed a likely candidate. We examined monensin's effect on basal and GRF-stimulated release of newly synthesized and stored rat growth hormone (rGH) and rat prolactin (rPRL). 14C-Pre-labeled, perifused rat pituitary fragments were exposed to [3H]leucine in 0-10 microM monensin; a pulse of 3 nM GRF assessed subsequent secretory responsivity. Monensin dose-dependently reduced basal release of stored [14C]rGH and [14C]rPRL. GRF-stimulated release of stored [14C]hormone was doubled after 0.03 microM and 0.1 microM monensin; higher concentrations diminished stored hormone release. Low concentrations of monensin accelerated basal (0.03 microM and 0.1 microM) and GRF-stimulated (0.03 microM) [3H]rGH and [3H]rPRL release without altering recovery; higher monensin concentrations (greater than or equal to 1 microM) reduced basal, and abolished GRF-stimulated, new hormone release and reduced total [3H]rGH and [3H]rPRL recovery. These data are consistent with a GRF-sensitive and monensin-influenced branch in intracellular hormone processing that regulates the fraction of new hormone exiting the cell without prior immersion in storage compartments.
当先前的数据表明细胞内激素加工存在对生长激素释放因子（GRF）敏感的分支时，对莫能菌素敏感的高尔基体似乎是一个可能的候选者。我们研究了莫能菌素对新合成和储存的大鼠生长激素（rGH）及大鼠催乳素（rPRL）基础分泌和GRF刺激分泌的影响。将预先用14C标记的灌流大鼠垂体碎片暴露于含0 - 10微摩尔莫能菌素的[3H]亮氨酸中；用3纳摩尔GRF脉冲刺激来评估随后的分泌反应性。莫能菌素剂量依赖性地降低了储存的[14C]rGH和[14C]rPRL的基础分泌。在0.03微摩尔和0.1微摩尔莫能菌素作用后，GRF刺激的储存[14C]激素分泌增加了一倍；更高浓度则减少了储存激素的分泌。低浓度的莫能菌素加速了基础（0.03微摩尔和0.1微摩尔）和GRF刺激（0.03微摩尔）的[3H]rGH和[3H]rPRL分泌，且不改变回收率；更高浓度的莫能菌素（大于或等于1微摩尔）降低了基础分泌，消除了GRF刺激的新激素分泌，并降低了总的[3H]rGH和[3H]rPRL回收率。这些数据与细胞内激素加工中一个对GRF敏感且受莫能菌素影响的分支相一致，该分支调节新激素在不预先进入储存区室的情况下离开细胞的比例。
