"Cascade" principle of the control of non-shivering thermogenesis by intravenously infused noradrenaline.

A hypothesis is presented according to which noradrenaline (NA) infused into the blood reaches the biophase of thermogenic cells through three "cascade" steps, namely the blood volume, extravascular space and biophase. The influx rate of the NA entering the system is given by a forcing function and multiplied by cardiac output. Distribution of the NA at each step is identically described by three differential equations.