白斑角鲨（Squalus acanthias）直肠腺小管中氯化钠分泌的机制。II. 抑制剂的作用
Mechanism of NaCl secretion in rectal gland tubules of spiny dogfish (Squalus acanthias). II. Effects of inhibitors.
作者信息
Greger R, Schlatter E
出版信息
Pflugers Arch. 1984 Dec;402(4):364-75. doi: 10.1007/BF00583937.
Rectal gland tubule (RGT) segments of the spiny dogfish (Squalus acanthias) were perfused in vitro. The effects of inhibitors of known mode of action on transepithelial PD (PDte resistance (Rte), the PD across the basolateral membrane (PDbl), the fractional resistance of this membrane (FRbl), and intracellular activities of NA+, Cl-, K+ (apha cell) were examined. Furosemide (5 x 10(-4) mol x 1(-1)) reduced PDte from -12 +/- 0.7 to -2.3 +/- 0.2 mV (n = 63), hyperpolarized PDbl from -71 +/- 1.3 to -79 +/- 0.9 mV (n = 59), FRbl decreased from 0.2 +/- 0.03 to 0.13 +/- 0.01 (n = 21), alpha cell cl- fell from 38 +/- 4 to 11 +/- 2 mmol x 1(-1) (n = 21), alpha cell Na+ fell from 37 +/- 4 to 17 +/- 2 mmol x 1(-1) (n = 12) and alpha cell K+ was constant [113 +/- 14 vs. 117 +/- 15 mmol x 1(-1) (n = 6)]. Furosemide exerted its effects within some 20-40s. Its action was completely reversible. Analysis of the time courses revealed that the furosemide induced initial fall in alpha cell cl- was approximately twice as rapid when compared to that of alpha cell Na+. Ba2+ 0.5 mmol x 1(-1) (bath) reduced PDte from -7.1 +/- 1.2 to -4.1 +/- 0.6 mV (n = 24), increased Rte from 18 +/- 2 to 22 +/- 2.5, omega cm2 (n = 14). PDbl depolarized from -75 +/- 2 to -48 +/- 2 mV (n = 42), FRbl increased from 0.2 +/- 0.02 to 0.34 +/- 0.04 (n = 14) and alpha cell K+ increased from 143 +/-28 to 188 +/- mmol x 1(-1) (n = 4). Ouabain (50 x 10(-6) mol x 1(-1), bath) reduced PDte from -12 +/-2 to -3 +/- 0.5 mV (n = 9), Rte increased from 18 +/- 3 to 21 +/- 3 omega cm2 (n = 5). PDbl depolarized from -67 +/- 4 to -26 + 3 mV (n = 14), FRbl increased from 0.23 +/- 0.04 to 0.45 +/- 0.05 (n = 6), alpha cell K+ fell only slightly from 135 +/- 15 to 112 +/- 30 mmol x 1(-1) (n = 4), but alpha cell cl- increased from 35 +/- 12 to 111 +/- 37 mmol x 1(-1) (n = 3). These effects of ouabain were slow when compared to those exerted by furosemide or Ba2+. The ouabain effects on PDte and PDbl were completely prevented if furosemide was applied first.(ABSTRACT TRUNCATED AT 400 WORDS)
对棘鲨（Squalus acanthias）的直肠腺小管（RGT）节段进行了体外灌注。研究了已知作用模式的抑制剂对跨上皮电位差（PDte）、电阻（Rte）、基底外侧膜两侧的电位差（PDbl）、该膜的分数电阻（FRbl）以及α细胞内Na⁺、Cl⁻、K⁺活性的影响。速尿（5×10⁻⁴ mol·L⁻¹）使PDte从-12±0.7 mV降至-2.3±0.2 mV（n = 63），使PDbl超极化，从-71±1.3 mV降至-79±0.9 mV（n = 59），FRbl从0.2±0.03降至0.13±0.01（n = 21），α细胞Cl⁻从38±4 mmol·L⁻¹降至11±2 mmol·L⁻¹（n = 21），α细胞Na⁺从37±4 mmol·L⁻¹降至17±2 mmol·L⁻¹（n = 12），而α细胞K⁺保持恒定[113±14对比117±15 mmol·L⁻¹（n = 6）]。速尿在约20 - 40秒内发挥作用，其作用完全可逆。对时间进程的分析表明，速尿诱导的α细胞Cl⁻初始下降速度约为α细胞Na⁺下降速度的两倍。0.5 mmol·L⁻¹（浴槽中）的Ba²⁺使PDte从-7.1±1.2 mV降至-4.1±0.6 mV（n = 24），使Rte从18±2增加至22±2.5 Ω·cm²（n = 14）。PDbl去极化，从-75±2 mV变为-48±2 mV（n = 42），FRbl从0.2±0.02增加至0.34±0.04（n = 14），α细胞K⁺从143±28 mmol·L⁻¹增加至188± mmol·L⁻¹（n = 4）。哇巴因（50×10⁻⁶ mol·L⁻¹，浴槽中）使PDte从-12±2 mV降至-3±0.5 mV（n = 9），Rte从18±3增加至21±3 Ω·cm²（n = 5）。PDbl去极化，从-67±4 mV变为-26 + 3 mV（n = 14），FRbl从0.23±0.04增加至0.45±0.05（n = 6），α细胞K⁺仅略有下降，从135±15 mmol·L⁻¹降至112±30 mmol·L⁻¹（n = 4），但α细胞Cl⁻从35±12 mmol·L⁻¹增加至111±37 mmol·L⁻¹（n = 3）。与速尿或Ba²⁺相比哇巴因的这些作用较慢。如果先应用速尿，哇巴因对PDte和PDbl的作用可完全被阻止。（摘要截断于400字）
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