Which GAGs are increased in interstitial tissue during myxedema?

In myxedema, which is often associated with severe hypothyroidism, there is an accumulation of glycosaminoglycans (GAGs) in the interstitial spaces of tissues. This accumulation is primarily due to the effects of thyroid hormone, which normally helps regulate the synthesis and degradation of these substances.

Chondroitin sulfate and hyaluronic acid are the specific GAGs involved in this condition. Chondroitin sulfate is a component of proteoglycans, which help provide structural support in cartilage and connective tissue, and its levels can increase in response to tissue swelling and inflammation. Hyaluronic acid, on the other hand, is a non-sulfated GAG that has a unique ability to attract water, leading to tissue swelling, which is characteristic of myxedema.

The combination of these GAGs contributes to the accumulation of water in the interstitial spaces, resulting in the classic myxedematous swelling. This characteristic finding plays a critical role in the pathophysiology of the condition and helps differentiate it from other forms of edema.