HSC Students Appear Tired of Endocrinology Labs

Actually, students are investigating (does not appear to be a very active investigation in the photo) the regulation and action of the hormone cortisol. Cortisol has a variety of effects on the body including carbohydrate, protein and lipid metabolism as well as modulation of immune system function. Many of its effects are designed to prepare the body for stress. Students performed several  labs that involved tracking cortisol levels or its effects. In one lab students demonstrated a change in the percentage of neutrophils and lymphocytes in mice with elevated plasma levels of cortisol resulting from confinement stress.

Another lab involved tracking the plasma levels of cortisol in students under control, stressed and relaxed conditions. It turns out that cortisol levels equilibrate rapidly between the plasma and saliva. Therefore salivary cortisol levels are an accurate indicator of blood cortisol concentration. Saliva samples were collected (drool collection) before and after a 20-minute guided relaxation. Then with the help of Dr. Hargadon and his plate-reader, ELISA was used to measure salivary cortisol levels.  Most of the students exhibited a significant drop in cortisol levels following the guided relaxation.

This was an interesting finding as the half-life of cortisol in the plasma is over 60 minutes. Who says biology labs cannot be relaxing….