Electrophysiological properties of testosterone-secreting cells studied with patch-clamp techniques- a comparison with neurosecretion.

用生理盐水灌流成年小鼠睾丸管间隙，机械分离睾丸间质细胞（Leydig细胞）。灌流液收集在记录室中，并根据其形态特征（直径13-20 <micrn>μ m，明亮的细胞边界，偶尔，成簇）鉴定Leydig细胞。3 -羟类固醇脱氢酶的特异性染色证实了鉴定的可靠<beta>性。保持电位为-80--95 mV，外部盐水含有126 mM NaCl、5 mM KCl和10 mM CaCl_2。去极化超过-40 mV诱发内向电流，在150 msec刺激期间完全衰减。内向电流被鉴定为Ca^&lt;2+&gt;携带电流，因为用Mn^&lt;2 +&gt;替代外部Ca^&lt;2 +&gt;会可逆地减少电流，而Ba^&lt;2+&gt;或Sr^&lt;2+&gt;替代Ca^&lt;2+&gt;。去极化至+40 mV时未诱发可测量的外向电流。Ca^&lt;2+&gt;通道可被膜电位的生理变化激活，导致Ca^&lt;2+&gt;内流。通过将两个贴片电极应用于一对细胞获得的平均耦合比为0.84。还证实了染料（荧光黄）转移或注入相邻细胞。细胞间偶联可能在同步或强化簇内Leydig细胞的内分泌活动中起作用。

The testosterone-secreting cells (Leydig cells) in adult mice were isolated mechanically by perfusing intertubular spaces of testes with physiological saline. Perfusates were collected in recording chamber and the Leydig cells were identified by their morphological characteristics (diameter 13-20 <micrn>m,bright cell-border, occasionally,clustered. Indentification was confirmed reliable by the specific staining of 3<beta>-hydroxysteroid dehydrogenase.The whole-cell membranes of Leydig cells were voltage-clamped with patch-electrodes. The holding potential was -80--95 mV and the external saline contained 126 mM NaCl, 5 mM KCl and 10 mM CaCl_2. Depolarization over -40 mV evoked inward currents which decayed completely during 150 msec stimuli. The inward currents were identified as Ca^<2+>-carried current, since replacement of external Ca^<2+> with Mn^<2+> reversibly diminished the current whereas Ba^<2+> or Sr^<2+> substituted for Ca^<2+> . No measurable outward currents were evoked by the depolarization up to +40 mV. The Ca^<2+> channels may be activated by physiological changes in membrane potential, leading to an influx of Ca^<2+>.Leydig cells within a cluster possessed distinct intercellular couplings. The mean coupling ratio obtained by applying two patch electrodes to a pair of cells was 0.84. Transfer or injected dye (Lucifer Yellow) to adjacent cells was also confirmed. Intercellular coupling may paly a role in synchronizing or intensifying the endocrine activities of Leydig cells located within a cluster.