新生大鼠和胎鼠胃钠和氯转运的体外发育情况

Development of sodium and chloride transport across fetal and newborn rat stomach in vitro.

Ducroc R, Garzon B, Geloso J P, Hervatin F, Millet P, Moreau E

Laboratoire de Différenciation Fonctionnelle, Université Paris 7, France.

J Physiol. 1988 Apr;398:543-54. doi: 10.1113/jphysiol.1988.sp017056.

Abstract

Unidirectional and net Na+ and Cl- fluxes were determined across isolated fetal rat stomach 19-21 days post-coitum, and across the stomach of newborn rats aged 5 or 12 days. 2. On fetal day 19, absorption of both Na+ and Cl- was greater than the short-circuit current, Isc (net Na+ flux, JnetNa = 4.7 +/- 1.0 and net Cl- flux, JnetCl = 5.4 +/- 1.4 mu equiv cm-2 h-1 vs. Isc = 0.9 +/- 0.1 mu equiv cm-2 h-1). Mucosal addition of 10 microM-amiloride did not significantly alter JnetNa, JnetCl, Isc or total conductance. 3. However, on fetal day 20, neutral absorption of NaCl was no longer observed but amiloride had inhibited electrogenic absorption of Na+, and significant active secretion of Cl- was observed (JnetCl = -1.3 +/- 0.6 mu equiv cm-2 h-1). On day 21 (i.e. 24 h before birth), values for JnetNa, JnetCl, and Isc were not different from those determined on adult gastric mucosa. 4. After birth, NaCl transport continued to exhibit its prenatal characteristics on day 5 but not on day 12, when Na+ and Cl- were both absorbed; on that day, JnetNa-Isc was equal to both JnetCl and to the amiloride-insensitive component of Isc, indicating that neutral NaCl absorption had resumed. 5. These data show that in rat stomach, NaCl transport differentiates on fetal day 20, when H+ secretion is first observed, and thereafter undergoes biphasic development. 6. The significant Cl- absorption observed on post-natal day 12 was concomitant with the inhibition of net H+ secretion.

摘要

测定了妊娠19 - 21天的离体胎鼠胃以及5日龄或12日龄新生鼠胃的单向和净Na⁺及Cl⁻通量。2. 在胎龄19天时，Na⁺和Cl⁻的吸收均大于短路电流Isc（净Na⁺通量JnetNa = 4.7±1.0，净Cl⁻通量JnetCl = 5.4±1.4μequiv cm⁻² h⁻¹，而Isc = 0.9±0.1μequiv cm⁻² h⁻¹）。向黏膜侧添加10μM氨氯吡咪并未显著改变JnetNa、JnetCl、Isc或总电导。3. 然而，在胎龄20天时，未再观察到NaCl的中性吸收，但氨氯吡咪抑制了Na⁺的电生性吸收，且观察到显著的Cl⁻主动分泌（JnetCl = -1.3±0.6μequiv cm⁻² h⁻¹）。在第21天（即出生前24小时），JnetNa、JnetCl和Isc的值与成年胃黏膜所测定的值无差异。4. 出生后，NaCl转运在第5天继续表现出其产前特征，但在第12天并非如此，此时Na⁺和Cl⁻均被吸收；在那一天，JnetNa - Isc等于JnetCl以及Isc的氨氯吡咪不敏感成分，表明中性NaCl吸收已恢复。5. 这些数据表明，在大鼠胃中，NaCl转运在胎龄20天（首次观察到H⁺分泌时）发生分化，此后经历双相发育。6. 在出生后第12天观察到的显著Cl⁻吸收与净H⁺分泌的抑制同时出现。