Four parameters regulate TSH (in the mathematical model (ref.1)):
k21 – (positive feedforward of TRH onto TSH (downstream, activating)),
c2 – (the secretory capacity constant),
k234 -negative feedback of FT4 and FT3 onto TSH (upstream, repressing) and
a2 – (the TSH elimination rate constant.).
Be aware that the colours for the hormones are different in the rows below.
Positive feedforward of TRH onto TSH (downstream, activating)):
Negative feedback of FT4 and FT3 onto TSH (upstream, repressing)
The TSH elimination rate constant.
The secretory capacity constant
Only examples of the effect of the parameter –
- Hoermann R, Pekker MJ, Midgley JEM, Larisch R and Dietrich JW (2022) Principles of Endocrine Regulation: Reconciling Tensions Between Robustness in Performance and Adaptation to Change. Front. Endocrinol. 13:825107. doi: 10.3389/fendo.2022.825107 https://www.frontiersin.org/articles/10.3389/fendo.2022.825107/full