This provides a biological basis for considering whether pharmacological GLP-1 therapies, which achieve much higher systemic levels, could also reach the joint and potentially have local effects. Additionally, scientists found that the level of GLP-1 hormone in the synovial fluid is directly tied to the levels in the blood of arthritis patients
Since its identification in the 1990s by the research group of Sikiric et al., it has become one of the most extensively studied peptides in tissue repair research, with published data spanning tendon healing, angiogenesis, nitric oxide regulation, and gastrointestinal cytoprotection
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Similarly, histamine is synthesized in numerous tissues by the decarboxylation of histidine catalyzed by histidine decarboxylase which is a pyridoxal phosphate-requiring (B6) enzyme
Viruses like SARS-CoV-2 preferentially infect cells with high ACE2 expression, such as thyroid and parathyroid cells, enabling rapid viral replication in these tissues