Meeting Abstract
P3.86 Saturday, Jan. 5 Isolated fish gills as a model for teaching osmotic permeability to undergraduate physiology students. FURIMSKY, M.*; ROBERTSON, J.; Westminster College, Pennsylvania; Westminster College, Pennsylvania furimsmm@westminster.edu
The fish gill represents an important interface between the organism and its external aquatic environment and is an excellent model that undergraduate physiology students can use for examining barrier epithelia and membrane structure and function. Lab exercises using this model system require access to fish (many common freshwater species are appropriate), simple aeration devices, milligram balances, an oven that can maintain a temperature of 100�C, and – depending on the activity being investigated – various chemical compounds. A protocol for preparing isolated gill arches, setting up permeation incubations and performing simple gravimetric measures of gill osmotic water weight gain is presented. Use of fish gills to study gradient-dependent osmotic permeability is described. Also presented is a method for examining paracellular versus transcellular osmotic permeability, based on calcium-dependent tight junction properties of the fish gill epithelium. Additionally, the effects of antibiotics that interact with membrane structural components to form pores and increase cell permeability can be readily observed with this system. All of the experimental treatments described show consistent concentration-dependent differences in osmotic permeability. This system is also highly amenable to inquiry-based pedagogical approaches. Advantages and drawbacks of the fish gill model and other common teaching laboratory models for investigating permeability are summarized and compared.
