Once the t-3 goes into the mitochondrion there has to be proper functioning mitochondrion to carry out the thyroid signaling from t3. One needs t3 to make the cellular energy work, but if the mitochondrion is not up to optimal capacity then one would not get the desired response from the thyroid hormone. When you are referring to thyroid signaling you are referring to its effect at the receptor level. If someone had a mitochondrial imbalance and t3 was given with no response, this may result in the doctor giving more t3 resolve the issue. See the real problem is not the thyroid, but rather at the cellular level. Traditional medicine needs to look at giving substrates to help to support mitochondrion function such as ubquinol, acetyl l-carnitine, citrates, iron, and especially NADH to help make the ATP and reduction in ROS. I have come across studies that show those with low thyroid hormones are also low in co-enzyme Q10 and iron, b-12, and many other vital nutrients. If nutrients are low this could affect the cellular signaling of the thyroid medicine not just by mitochondrion imbalance, but also methylation. Proper methylation is needed to boost adequate levels of glutathione for the thyroid to work efficiently at the receptor level.
So to summarize thyroid start to finish:
1. Pituitary signaling to the formation of t4 and t3
2 Thyroid Absorption into to the blood
3. Thyroid conversion t-4 to t3,t2 (liver and kidneys)
4. Thyroid receptor activation by thyroid entering the tissue (cortisol, iron)
5. Ability for mitochondrion to respond to increase thyroid demands
When a person goes to a traditional doctor, the doctor really may be looking at only 15-20% of the equation leaving out the other 80-85%. Unfortunately doctors are not taught in medical school to look at these missing factors. With the introduction of Bio-individualized Medicine we hope to help educate medical professionals to look at things on a different plane to get the best outcome for their patients.=