Osmotic regulation of taurine transport via system beta and novel processes in mouse preimplantation conceptuses.
Osmotic regulation of taurine transport via system beta and novel processes in mouse preimplantation conceptuses.
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通过系统β和小鼠植入前概念中的新过程对牛磺酸转运的渗透调节。
DOI：
10.1016/0005-2736(94)90175-9
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Campione,AL
中科院分区：
文献类型：
--
作者：
VanWinkle,LJ;Patel,M;Wasserlauf,HG;Dickinson,HR;Campione,AL
牛磺酸最近被证明可以增加2-细胞小鼠胚胎在体外发育成囊胚的频率。由于这个原因，因为牛磺酸有助于细胞适应外部压力，我们研究了这种和相关的氨基酸的运输植入前小鼠的概念。在1-细胞至胚泡发育阶段，牛磺酸在孕体中转运的最显著成分是Na+和Cl −依赖性的。这种Na +-和Cl −-依赖的转运系统与β-氨基酸而不是α-氨基酸相互作用相对较强。根据这些标准，转运系统β负责植入前小鼠胚胎中Na+依赖的牛磺酸转运。此外，在早期胚胎中检测到编码牛磺酸转运蛋白（TAUT）的mRNA支持了TAUT是系统β的主要组成部分的理论。在低渗培养液中，1-细胞胚胎中β系统转运牛磺酸的速度比高渗培养液慢，而在囊胚中β系统转运牛磺酸的速度则相反。相比之下，低渗刺激的Na +-非依赖性牛磺酸运输，当然，在低渗比在高渗介质中的1-细胞概念和囊胚更迅速。通过这种低渗刺激过程的运输也没有表现出饱和的迹象，高达10 mM的牛磺酸。低渗刺激牛磺酸运输出现短暂的1-细胞概念在低渗条件下，直到他们已经恢复其初始体积。因此，我们认为通过系统β的牛磺酸摄取的减少和通过Na+非依赖性的非饱和转运过程的牛磺酸流出的增加可能有助于在低渗培养基中的1-细胞孕体的调节性体积减少。然而，由于囊胚中β系统对牛磺酸的摄取在低渗培养基中高于高渗培养基，因此囊胚中β系统对牛磺酸的摄取可能会加剧低渗培养基中细胞体积增加的趋势。这种牛磺酸摄取的增加可能进一步有利于与细胞肿胀相关的合成代谢变化。除了有助于调节细胞体积和代谢，低渗刺激的Na +-独立的运输过程中早期胚胎有新的特点。硝氟酯、N-乙基马来酰亚胺和NaN3可抑制低渗刺激的Na+非依赖性牛磺酸转运，但呋塞米、碘乙酸、KCN、哇巴因或α-或β-氨基酸均不抑制。此外，4，4 ′-二异硫氰基芪-2，2 ′-二磺酸盐在1-细胞胚胎中抑制这种转运，但在囊胚中不抑制。因此，不同的低渗刺激的Na +-独立牛磺酸运输过程中出现的1-细胞概念与囊胚。这些和其他情况下的功能发育调控表达的运输过程在植入前的概念仍然在很大程度上有待阐明。此外，无论是低渗刺激Na +-独立牛磺酸运输过程中的概念似乎已被检测到在其他类型的细胞。相反，这些过程可能是唯一的植入前概念。
Taurine was shown recently to increase the frequency at which 2-cell mouse conceptuses develop into blastocysts in vitro. For this reason and because taurine helps cells adapt to external stresses, we studied transport of this and related amino acids by preimplantation mouse conceptuses. The most conspicuous component of taurine transport in conceptuses at the 1-cell through blastocyst stages of development was both Na+-and Cl−-dependent. This Na+-and Cl−-dependent transport system interacted relatively strongly with β-but not α-amino acids. By these criteria, transport system β is responsible for Na+-dependent taurine transport in preimplantation mouse conceptuses. Moreover, detection of mRNA encoding the taurine transport protein (TAUT) in early conceptuses supports the theory that TAUT is a major component of system β. Transport of taurine by system β in 1-cell conceptuses was slower in hypotonic than in hypertonic media, whereas the reverse was true for system β in blastocysts. In contrast, hypotonically stimulated Na+-independent taurine transport was, of course, more rapid in hypotonic than in hypertonic media in both 1-cell conceptuses and blastocysts. Transport via this hypotonically stimulated process also showed no sign of saturation by up to 10 mM taurine. Hypotonically stimulated taurine transport appeared transiently in 1-cell conceptuses under hypotonic conditions until they had recovered their initial volumes. Hence, we suggest that a decrease in taurine uptake via system β and an increase in taurine exodus via the Na+-independent, nonsaturable transport process could contribute to the regulatory volume decrease in 1-cell conceptuses in hypotonic medium. Since taurine uptake by system β in blastocysts is, however, higher in hypotonic than in hypertonic media, taurine uptake by system β in blastocysts might intensify a tendency to increase cell volume in hypotonic medium. Such an increase in taurine uptake could further favor anabolic changes associated with cell swelling. In addition to contributing to regulation of cellular volume and perhaps metabolism, the hypotonically stimulated Na+-independent transport processes in early embryos have novel characteristics. Hypotonically stimulated Na+-independent taurine transport was inhibited by niflumate, N-ethylmaleimide and NaN 3 but not by furosemide, iodoacetate, KCN, ouabain or α-or β-amino acids. Furthermore, 4, 4′-diisothiocyanostilbene-2, 2′-disulfonate inhibited this transport in 1-cell conceptuses but not in blastocysts. Hence, different hypotonically stimulated Na+-independent taurine transport processes appear to be present in 1-cell conceptuses vs. blastocysts. The functions of these and other instances of developmental regulation of expression of transport processes in preimplantation conceptuses remain largely to be elucidated. Moreover, neither of the hypotonically stimulated Na+-independent taurine transport processes in conceptuses appears to have been detected in other types of cells. Instead, these processes may be unique to preimplantation conceptuses.
氟伏沙明和氯米帕明治疗内源性抑郁症。
影响因子：
6.6
作者：
J.E.M. De Wilde;D. Doogan
通讯作者：
D. Doogan
电子捕获气相色谱法测定人血浆中的克洛沙明浓度。
影响因子：
9.3
作者：
H. Hurst;D. Jones;C. Jarboe;H. deBree
通讯作者：
H. deBree