1. Endocrinology: Cortisol
Biology 304 Lab
Gina Neonakis & Michelle McPherson
March 6, 2013

2. 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

3. Cortisol Secretion Glucocorticoid
Brain perceives stress ↓ Hypothalamus- CRH ↓ Pituitary Gland- ACTH ↓ Adrenal Gland- Cortisol
Figure 1. Hormonal pathway caused by stress (Talbott & Kraemer, 2007).

4. 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).

5. Figure 3. Normal stress response (Talbott & Kraemer, 2007).
Figure 4. Modern human stress response (Talbott & Kraemer, 2007).

6. 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

7. 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

8. 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

9. Results TRH TSH ACTH Cortisol Testosterone normal
Testosterone castrate
LH norm
LH castrate
Pituitary + -
Adrenal
Thyroid
Thymus
Testes
Prostate
Seminal Vesicles
Body weight

10. 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

11. Questions?