Venkatachalam M A, Kreisberg J I
Am J Physiol. 1985 Jul;249(1 Pt 1):C48-55. doi: 10.1152/ajpcell.1985.249.1.C48.
Contractile cells under conditions of prolonged culture lose their ability to contract in the usual manner (i.e., isotonically). One explanation for this may be that contraction is prevented by tight cell-to-substrate adhesion. Two models in which substrate adhesiveness was expected to be diminished were used to test this hypothesis. In one, cells were seeded onto collagen-coated dishes and used within 40 min of plating. In the other, cells were plated onto dishes coated with poly-2-hydroxyethyl methacrylate (poly-HEMA) and used, depending on thickness of the poly-HEMA substrate, up to periods of 1 wk. Cells plated onto such substrates contracted when challenged with either PGE2 (2 X 10(-6) and 2 X 10(-9) M), arginine vasopressin (AVP, 10(-6)-10(-9) ), or the calcium ionophore A23187 (5 micrograms/ml). Contraction took place within 5-15 min at 37 degrees C. The contraction seen with AVP was due to its pressor action because 1-desamino-8-D-arginine vasopressin (dDAVP), the antidiuretic analogue, did not cause contraction and the anti-pressor analogue [1-(beta-mercapto-beta beta-cyclopentamethylene propionic acid)-4-valine 8-D-arginine]-vasopressin [d(CH2)5-VDAVP] blocked contraction by AVP. The contraction seen with AVP was dependent on extracellular calcium, whereas that observed with prostaglandin E2 (PGE2) was not.(ABSTRACT TRUNCATED AT 250 WORDS)
在长期培养条件下，收缩性细胞会丧失以常规方式（即等张收缩）收缩的能力。对此的一种解释可能是紧密的细胞与底物黏附阻止了收缩。使用了两种预期底物黏附性会降低的模型来检验这一假设。一种模型中，将细胞接种到包被有胶原蛋白的培养皿上，并在接种后40分钟内使用。另一种模型中，将细胞接种到包被有聚甲基丙烯酸2-羟乙酯（poly-HEMA）的培养皿上，根据poly-HEMA底物的厚度，可使用长达1周的时间。接种到此类底物上的细胞在用前列腺素E2（PGE2，2×10⁻⁶和2×10⁻⁹ M）、精氨酸加压素（AVP，10⁻⁶ - 10⁻⁹）或钙离子载体A23187（5微克/毫升）刺激时会收缩。在37℃下，收缩在5 - 15分钟内发生。AVP引起的收缩是由于其升压作用，因为抗利尿类似物1-去氨基-8-D-精氨酸加压素（dDAVP）不会引起收缩，而抗升压类似物[1-(β-巯基-β-β-环戊亚甲基丙酸)-4-缬氨酸8-D-精氨酸]-加压素[d(CH₂)₅-VDAVP]可阻断AVP引起的收缩。AVP引起的收缩依赖于细胞外钙，而前列腺素E2（PGE2）引起的收缩则不依赖。（摘要截短至250字）
