Fig. 2: Step changes in parameters cause transient responses and a return to baseline over weeks.

Simulations began at steady state with nominal parameter values, and then at \(t=0\) one parameter was changed as indicated, causing a rapid change followed by recovery to the new steady state level, which in all cases is identical to the pre-change level. Blue horizontal line is no change from the nominal parameter (see schematic in panel a). a−c Class 3 circuit metabolite and hormone dynamics upon changes in: a hormone sensitivity, \(s\). b hormone specific production rate (maximal secretion rate per unit biomass of secreting cell type), \(q\). c rate constant for hormone removal, \(r\). d−f Class 4 hormone or metabolite dynamics upon changes in: d rate constant for hormone removal, \(r\). e metabolite specific production rate (maximal secretion rate per unit biomass of secreting cell type), \(q\). f rate constant for metabolite removal, \(a\). g-l Class 5 circuit dynamics of the three hormones: g hormone 1 dynamics with different values of hormone-specific production rate, \({q}_{1}\). h hormone 1 dynamics with different values of rate constant for hormone removal, \({r}_{1}\). i hormone 2 dynamics with different values of hormone-specific production rate, \({q}_{2}\). j hormone 2 dynamics with different values of rate constant for hormone removal, \({r}_{2}\). k hormone 3 dynamics with different values of hormone-specific production rate, \({q}_{3}\). l hormone 3 dynamics with different values of rate constant for hormone removal, \({r}_{3}\). Parameters not varied in this figure are as in Fig. 1. See Box 1 for model equations.