Experiences on measuring of red blood cell deformability in laboratory animals

An important element of hematological measurements is the definition of red blood cell deformability. For the standard measuring technique of philtrometers, used in Hungary, 2,5 ml blood is necessary. Such amount of blood cannot be taken from laboratory animals, especially not in follow-up experiments, when daily blood taking may be necessary. Furthermore, differences between deformability of different species' red blood cells are not clear. Deformability was defined by relative cell transit time (RCTT). The authors summarize their experiences with measurings with Carat-FT-1 philtrometer on different species (mouse, rat, rabbit, dog and pig). As preliminary studies, they used 20 rats, using standard amount (2-2,5 ml) of blood, according to original method and they measured deformability after 1 week. They performed measurings also on cell suspensions of 1, 2, and 4% PCV. Their results showed significant species specificity and deformability values correlating to red blood cell size, characteristic to the given species. In rats, when taking standard amount of blood, RCTT value of the sample taken 1 week later was significantly lower than the basic measure (P<0,01), which indicates that in case of laboratory animals, standard amount of blood is not suitable for follow-up studies, because it may give false negative result. According to their results, comparative studies on experiments in different species may only be performed by taking into account of species specificity.