Allometric scaling relationship between frequency of intestinal contraction and body size in rodents and rabbits.

ABSTRACT

This study aimed to establish an allometric scaling relationship between the frequency of intestinal contractions and body mass of different mammalian species. The frequency of intestinal contractions of rabbit, guinea pig, rat and mouse were measured using an isolated organ system. The isolated rings were prepared from proximal segments of jejunums and the frequency of contractions was recorded by an isometric force procedure. The coefficients of the obtained allometric equation were ascertained by computation of least squares after logarithmic transformation of both body mass and frequency. Significant differences (p<0.001) were shown in the frequency of contractions between different species. The highest frequency that corresponded to the mice was 57.7 min−1 and the 95% confidence interval (CI) ranged from 45.4 to 70, while rabbits showed the lowest frequency (12.71 min−1, CI 8.6–16.8). Logarithms of frequency were statistically proportional to logarithms of body mass (r00.99; p<0.001). The data fitted an equation F ¼ 1851B 031 and the 95% confidence interval of the exponent ranged from −0.30 to −0.32. The results of this study suggest that it is probably possible to extrapolate the intestinal contraction frequency of other mammalian species by the means of allometry scaling.