Kwok L S, Klyce S D
Department of Ophthalmology, Louisiana State University Medical Center School of Medicine, New Orleans 70112-2234.
Biophys J. 1990 Mar;57(3):657-62. doi: 10.1016/S0006-3495(90)82584-4.
In the rabbit corneal stroma, the swelling pressure, P, has been reported to have an anomalous (negative) temperature coefficient, alpha P, contradicting traditional Donnan swelling theory. A parallel-plate, diffuse double layer Gouy-Chapman model was used to resolve this discrepancy. The present model incorporates the possibility that surface charge, sigma, is temperature dependent. It is shown that negative, zero, or positive coefficients of swelling pressure change with temperature are not mutually exclusive conditions, but can be attributed to the same underlying mechanism. For likely values of alpha P(range -7 x 10(-3) K-1 to +3.2 x 10(-3)K-1), the effective stromal charge has a negative temperature dependency, or dln sigma/dT less than 0. The present formalism is robust against variation in assumed alpha P, and is able to simultaneously satisfy the known values of swelling pressure, its thermal dependency, and stromal charge. These results implicate significant coulombic forces behind P. Predicted stromal surface charge is approximately 0.01 Cm-2. The predictions were confirmed with macrocontinuum Donnan swelling theory, suggesting that Donnan osmotic swelling is the principal macroscopic component of P.
在兔角膜基质中，据报道肿胀压力P具有反常（负）温度系数αP，这与传统的唐南肿胀理论相矛盾。采用平行板、扩散双层古伊-查普曼模型来解决这一差异。本模型考虑了表面电荷σ随温度变化的可能性。结果表明，肿胀压力随温度变化的负、零或正系数并非相互排斥的条件，而是可归因于相同的潜在机制。对于αP的可能值（范围为-7×10⁻³K⁻¹至+3.2×10⁻³K⁻¹），有效基质电荷具有负温度依赖性，即dlnσ/dT＜0。本形式体系对假设的αP变化具有鲁棒性，并且能够同时满足已知的肿胀压力值、其热依赖性和基质电荷。这些结果表明P背后存在显著的库仑力。预测的基质表面电荷约为0.01 Cm⁻²。用宏观连续体唐南肿胀理论证实了这些预测，表明唐南渗透肿胀是P的主要宏观组成部分。
