title: Water self-diffusion in the calf lens.
abstract: Proton pulsed gradient spin echo (PGSE) nuclear magnetic resonance (NMR) spectroscopy was used to explore the free and restricted non-Brownian nature of lens water self-diffusion in calf lens tissue. At all temperatures investigated the water self-diffusion coefficient (Dw) of the cortical homogenate (25% protein) was 1.6-1.7 times greater than that for the nucleus (42% protein), and 0.3-0.5 times the value of Dw for pure water. The nuclear lens homogenate displayed anomalous temperature dependent water diffusion behavior, i.e. a departure from the smooth monotonic decrease in Dw with decreasing temperature, in the temperature range of 3-5 degrees C. By contrast, no such behavior was observed for cortical homogenate. Analysis of water proton echo attenuation data employing a parallel-plate model of restricted diffusion provided values for the parallel-plate barrier separation and self-diffusion coefficient in the limit of free diffusion. Nuclear material showed a smaller spatially average barrier separation and a significantly stronger barrier separation temperature dependence than cortical material.
authors: Department of Chemistry, University of California, Santa Cruz 95064.
authors: R L
authors: RL
authors: Haner
authors: T
authors: T
authors: Schleich
authors: C F
authors: CF
authors: Morgan
authors: J M
authors: JM
authors: Rydzewski
mesh_terms: D000818:Animals; D001834:Body Water / Q000378:metabolism*; D002417:Cattle; D004058:Diffusion; D007904:Lens Cortex, Crystalline / Q000378:metabolism*; D007907:Lens Nucleus, Crystalline / Q000378:metabolism*; D007908:Lens, Crystalline / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy