Endocrinology: Cortisol Biology 304 Lab Gina Neonakis & Michelle McPherson March 6, 2013
What is Cortisol? Regulates blood pressure, glucose metabolism, insulin release, immune function and inflammatory response. Secreted by the adrenal gland Termed the “Stress Hormone” Hydrocortisone creams
Cortisol Secretion Glucocorticoid Brain perceives stress ↓ Hypothalamus- CRH ↓ Pituitary Gland- ACTH ↓ Adrenal Gland- Cortisol Figure 1. Hormonal pathway caused by stress (Talbott & Kraemer, 2007).
Cortisol Rhythm Follows a circadian rhythm Highest level 6:00am-8:00am Lowest level 12:00am-2:00am Figure 2. A normal cortisol rhythm (Talbott & Kraemer, 2007).
Figure 3. Normal stress response (Talbott & Kraemer, 2007). Figure 4. Modern human stress response (Talbott & Kraemer, 2007).
Materials and Methods 6 hormones ; ACTH, cortisol, LH, TSH, TSR and testosterone Six sets of four adult male rats One experimental set One control set Fed rat chow and were given fresh water Two experimental rats were injected everyday with specified hormone Two control rats injected everyday with saline Two week injection period Euthanized by a intraperitoneal injection
Results Hormone 11 Controls Normal body mass = 172 Castrate body mass = 195 Pituitary 9.6 9.4 Thyroid 212 214 Thymus 364 372 Adrenals 28 26 Seminal Vesicles 484 454 Prostate 431 394 Testes 3201 n/a Normal body mass = 300 g Castrate body mass = 270 g Pituitary 12.9 Thyroid 250 Thymus 475 470 Adrenals 40 Seminal Vesicles 500 460 Prostate 425 392 Testes 3200 n/a
Results When comparing the control rats with the experimental rats these are the size differences we observed: Pituitary: decrease Thyroid: decrease Thymus: decrease Adrenals: decrease Seminal Vesicles: decrease Prostate: no significant change Testes: no change and n/a
Results TRH TSH ACTH Cortisol Testosterone normal Testosterone castrate LH norm LH castrate Pituitary + - Adrenal Thyroid Thymus Testes Prostate Seminal Vesicles Body weight
Results Unknown hormone 11 is Cortisol Effects of high cortisol : fatigue, lowered immunity, increase fat deposits, can cause Cushing’s disease Ways to prevent hyper secretion of cortisol : yoga, exercise, stress relieving activities
Questions?