Lecture 11

derived from the (cholesterol framework) Move across membranes and bind inside the cell Thyroid hormones is an example

Too large/polar to cross membranes Act on protein receptors at the cell surface which triggers signals to the cell

are inactive forms of hormones Converted to active form by enzymes

Hormones are found at much lower concentrations than other clinical analytes Radioimmunoassay developed in the 1960s are the reference method though being replaced by ELISA Assays

Both “Fight or flight” hormones Stimulate lipolysis/glycogenesis, increase heart rate -> making more energy available both Catecholamine hormones secreted by Adrenal Medulla

Epinephrine it is also more abundant

Growth Hormone (GH), Follicle Stimulating Hormone (FSH), and Luteinizing Hormone (LH)

Peptide Hormones

Growth and fertility -especially during puberty

Ovulation

stimulates glycogenesis/lipolysis making more energy available

T3 and T4 (aka thyroxine) are thyroid hormones affects metabolism, growth and activity of other hormones

A prohormone converted to T3 by Thyroglobulin

Steroid hormones Able to cross cell membrane due to them being non polar

Thyroid stimulating hormone elevated when T3/T4 is low and needs to produce more

Grave’s disease

Hashimoto’s thyroiditis

steroid hormones that affect glucose metabolism

major glucocorticoid Stimulates glycogenesis/lipolysis and reduces inflammation

the stress hormone b/c stress = elevated levels

Steroid hormones that affect mineral (electrolyte) absorption are called Mineralocorticoids

Aldosterone

Adrenal Cortex

the precursor for both M and F hormones the most abundant, though not the most potent, steroid hormone