Fedde M R
J Gen Physiol. 1969 May;53(5):624-37. doi: 10.1085/jgp.53.5.624.
Membrane constants and distribution of acetylcholine (ACh) receptors were determined for multiply innervated fibers of the anterior latissimus dorsi (ALD) and singly innervated fibers of the posterior latissimus dorsi (PLD) muscles of 3-6 month old chickens. The values of the various membrane constants were: length constant, 1.78 mm (mean) in ALD, 0.68 mm in PLD; time constant, 35 msec in ALD, 3.7 msec in PLD; transverse membrane resistance, 4388 ohm cm(2) in ALD, 561 ohm cm(2) in PLD; and membrane capacitance, 8.2 microF/cm(2) in ALD, 7.0 microF/cm(2) in PLD. Peaks of ACh sensitivity occurred at intervals of ca. 740 micro on ALD fibers with a low sensitivity remaining between peaks. Only one peak of ACh sensitivity was detected on PLD fibers. The maximum ACh sensitivity found was 5 +/- 4 mv/ncoul for fibers of the ALD and 77 +/- 60 mv/ncoul for fibers of the PLD. The distance over which this sensitivity fell to 0.1 was ca. 225 micro in the ALD and 140 micro in the PLD. The membranes of these two muscle fiber types differ widely regarding some electrical properties and the disposition of ACh-sensitive receptor sites.
测定了3至6月龄鸡的背阔肌前部（ALD）多重神经支配纤维和背阔肌后部（PLD）单重神经支配纤维的膜常数及乙酰胆碱（ACh）受体分布。各种膜常数的值如下：长度常数，ALD中为1.78毫米（平均值），PLD中为0.68毫米；时间常数，ALD中为35毫秒，PLD中为3.7毫秒；横向膜电阻，ALD中为4388欧姆·厘米²，PLD中为561欧姆·厘米²；膜电容，ALD中为8.2微法/厘米²，PLD中为7.0微法/厘米²。ALD纤维上ACh敏感性峰值间隔约为740微米出现，峰值之间保持低敏感性。在PLD纤维上仅检测到一个ACh敏感性峰值。所发现的最大ACh敏感性，ALD纤维为5±4毫伏/纳库仑，PLD纤维为77±60毫伏/纳库仑。这种敏感性降至0.1时的距离，ALD中约为225微米，PLD中约为140微米。这两种肌纤维类型的膜在一些电特性和ACh敏感受体位点的分布方面差异很大。
