Introduction to Endocrine Focus Series

Extract

The endocrine system is a complex system responsible for regulating many body functions through an elaborate network of hormones. The field of endocrinology enjoys a rather rich history; but it is a young history. Terms such as hormone and endocrinology were introduced in 1905 and 1909, respectively, and the study of endocrine function began in the late nineteenth century (1890 – 1905). The first comprehensive endocrinology textbook was published in 1913 and since that time, growth in the field of endocrinology has been exponential. As a result of the complex nature of the endocrine system, the diagnosis, management, and treatment of endocrine disturbances have always been challenging. Laboratory diagnosis has ranged from a panel of laboratory tests including total and free hormone levels, uptake tests, and stimulation tests to definitive guidelines for diagnosing endocrine disturbance using sometimes fewer than two laboratory tests.

Of the hormone assays performed in clinical chemistry, the most common are those associated with the thyroid gland. Numerous vendors have found ways to incorporate the thyroid hormone testing on automated platforms. Less common but equally called for are the hormone assays associated with the adrenal gland. The foundation of the hormone physiology is the negative feedback mechanism. Both thyroid hormones and adrenal hormones demonstrate this mechanism. Both have hypothalamic and pituitary hormones that respond to the gland-produced hormone in a negative feedback way.

This series of articles examines the physiology and pathology associated with thyroid and adrenal hormones. How these hormones impact our metabolism normally and in…