With advances in research techniques involving molecular biology, the need for precision in the determination of surface area is even greater than previously. This study sets out to determine the most accurate Meeh constant, k, for a commonly used weight range of experimental rats. The importance of a narrow weight range is appreciated and planometric data is presented from a series of adolescent mts that allow a new k value to be calculated. The figures presented here represent the largest number of animals, of a commonly used rat strain, in the most widely used weight range yet described. Pelts were removed from 16 anaesthetized male Sprague-Dawley rats after cervical dislocation. For each animal total body surface area (TBSA) was determined planometrically, along with premarked areas on the dorsal and ventral surfaces. Entering the planometrically measured data along with the animal's weight into the Meeh formula, a k value was obtained for each rat. Surface areas were then calculated for each animal using the mean k, 9.46, and compared against figures obtained by using historical values for the Meeh constant. Using the new k value a method is described for the accurate determination of total body surface area and premarked surface areas, in experimental rats of a specific weight range. Copyright (C) 1996 Elsevier Science Ltd for ISBI.
