Thyroid Hormone Transport into Cellular Tissue

Thyroid Hormone Transport into Cellular Tissue

Thyroid Hormone Transport into Cellular Tissue | Lomita CompoundingLatest research indicates that thyroid hormone transport across cellular membranes has a key role to play in tissue thyroid levels. It is important for physicians to be aware of the new developments and the increasing understanding of the thyroid hormone transport.

Overdependence on the sole use of standard thyroid blood tests to determine the presence or absence of hyperthyroidism can result in misdiagnosis of many hypothyroid patients. Overconfidence in the diagnostic accuracy of standard thyroid tests may create problems in the wake of a range of common co-morbid conditions present in a large part of the population.

Compounding pharmacy presents effective solutions to treat thyroid related conditions where commercially produced drugs may not prove to be useful or may not be available. American Integrative Pharmacy receives patients from Long Beach, Torrance, Los Angeles, South Bay Orange County, Southern California areas and nationwide for various compounding treatments.

Importance of Transport Processes

Serum thyroid levels are commonly used as an indicator of tissue thyroid activity. But to have biological activity, T3 and T4 must cross the cellular membrane from the serum into the target cells. Therefore, it follows that the activity of these transport processes would have a key influence on the regulation of biological activity of these hormones.

For nearly 25 years, it has been assumed that the extent and rate of uptake of thyroid hormone into the cells takes place through simple diffusion, which is driven by the concentration gradient of the free hormones in the serum. This diffusion hypothesis came about over half a century ago and it assumes that the serum concentration of free T3 and free T4 will eventually determine intracellular thyroid hormone concentrations.

However, recent research has questioned this diffusion mechanism hypothesis, showing that the transport of T3 and T4 across the cellular membrane into the cell requires active transport and not passive diffusion. The challenge is that even when new evidence to the contrary is accumulating, the misconceived diffusion hypothesis continues to be perpetuated.


The intra cellular level of T3 is the most significant determinant of thyroid activity, and a key determinant of this intra cellular T3 level is the activity of the cellular thyroid transporters.

A wide variety of common conditions such as insulin resistance, diabetes, depression, bipolar disorder, hyperlipidemia (high cholesterol and triglycerides), chronic fatigue syndrome, fibromyalgia, neurodegenerative diseases (Alzheimer’s, Parkinson’s and multiple sclerosis), migraines, stress, anxiety, chronic dieting and aging are associated with reduced thyroid transport into the cell.

Standard thyroid tests are a weak indicator of cellular thyroid levels in these patient populations because of the high incidence of reduced cellular thyroid transport seen with these conditions. The transporters in the pituitary are different than every other tissue in the body. Secondly, the thyroid transporters in the body are highly energy dependent and are impacted by various conditions while the pituitary is minimally impacted.

As the pituitary remains largely unaffected, there is no elevation in TSH levels despite widespread tissue hypothyroidism. Therefore, TSH is an inaccurate marker for tissue T3 levels for various patients. AIP provides a comprehensive range of services, including online prescription refills, to patients in Long Beach, Torrance, Los Angeles, South Bay Orange County, Southern California areas, and nationwide.

For more information on compound medications available or to make an online prescription purchase, please click here or call Toll Free 1-855-247-7948.

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American Integrative Pharmacy is located in Lomita, CA serving residents in and around Orange County, Los Angeles, Long Beach, Torrance and surrounding areas. Online prescription sales are available across the US.

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