title: Allometric cascade as a unifying principle of body mass effects on metabolism.
abstract: The power function of basal metabolic rate scaling is expressed as aM(b), where a corresponds to a scaling constant (intercept), M is body mass, and b is the scaling exponent. The 3/4 power law (the best-fit b value for mammals) was developed from Kleiber's original analysis and, since then, most workers have searched for a single cause to explain the observed allometry. Here we present a multiple-causes model of allometry, where the exponent b is the sum of the influences of multiple contributors to metabolism and control. The relative strength of each contributor, with its own characteristic exponent value, is determined by the control contribution. To illustrate its use, we apply this model to maximum versus basal metabolic rates to explain the differing scaling behaviour of these two biological states in mammals. The main difference in scaling is that, for the basal metabolic rate, the O(2) delivery steps contribute almost nothing to the global b scaling exponent, whereas for the maximum metabolic rate, the O(2) delivery steps significantly increase the global b value.
authors: Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
authors: Charles-A
authors: CA
authors: Darveau
authors: Raul K
authors: RK
authors: Suarez
authors: Russel D
authors: RD
authors: Andrews
authors: Peter W
authors: PW
authors: Hochachka
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001481:Basal Metabolism; D001835:Body Weight; D008322:Mammals / Q000378:metabolism*; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D000255:Adenosine Triphosphate; D000254:Sodium-Potassium-Exchanging ATPase; D010100:Oxygen