Wednesday, 14 September Chapter 11 The Endocrine System Classes of hormones The adrenal gland Fates of hormones Control of hormone secretion Hormone interactions (permissive effects) Hypothalamus & Pituitary The story of Aunt Dot Endocrine disorders (lab next week)

1QQ # 4 8:30 am 1.What changes in hepatocyte metabolism are produced by glucagon? 2.A) What advise would you give to a person who is a reactive hypoglycemic and B) provide the reasons for your advise. 3.Your patients plasma glucose level is 45 mg/dl. A) What hormone is responsible for her rapid heart rate, pale clammy skin, and irritability? B) Why does she have a headache?

1QQ # 4 9:30 am 1.Explain in some detail how beta cells of the Islets of Langerhans are affected by anticipating an excellent meal. 2.A) Describe a situation that would lead to the activation of the sympathetic nervous system. B) How does sympathetic stimulation affect the secretion from beta cells in the Islets of Langerhans? C) Why is this beneficial for the person in terms of fuel supply? 3.After an overnight fast, a patient arrives for an Oral Glucose Tolerance Test. The first blood sample (even before ingestion of the Tru-Glu cola shows a plasma glucose concentration of 150 mg/dl. A) Do you have the patient drink the Tru-Glu? Why or why not? B) What might you do next to determine what is “wrong” with your patient?

Class activity 24 students were hormones and we classified these hormones as amines, peptides or steroids, considered how they are synthesized and stored (or not) in secretory cells, transported in the plasma, the locations of their receptors in/on target cells, the nature of the response in target cells (latency & duration),

24 Hormones, 24 Students Corticosterone Testosterone Estriol Cortisol Aldosterone Estrone TSH ADH CRH TRH PTH LH Glucagon DA EPI NE T3 Insulin T4 GH ACTH FSH EPO CCK

Endocrine Organs (Table 11-1) Pituitary Gland Thyroid Gland Pancreas Gonads Gastrointestinal Tract Heart Kidney Hypothalamus Liver Etc. Hormone: chemical messengers carried by blood to target cells upon which they act. Only those cells having receptors Can respond to a given hormone Hormone Paracrine agent Autocrine agent Neurotransmitter Neuromodulator

3 Chemical Classes of Hormones 1: Amine hormones (from amino acid tyrosine) –Thyroid hormones –Adrenal medullary hormones (catecholamines) 2: Peptide hormones (peptides & proteins) 3: Steroid Hormones (derivatives of cholesterol)

Fig Catecholamines soluble in plasma Thyroid Hormones Not soluble in plasma, bound & free Amine Hormones Adrenal medulla NT

Fig Steroid hormones not soluble in plasma, not storable in vesicles Target cells have intracellular receptors. Changes is gene expression. Timecourse: longer latency, longer lasting Bound & Free

Fig Peptide Hormones Examples of Peptide Hormones: Insulin, glucagon prolactin, erythropoietin, parathyroid hormone, gastrin, leptin, growth hormone, oxytocin, vasopressin, FSH, LH, GHRH, and many more! Cell surface receptors on target cells Guess peptide! Soluble in plasma e.g. Beta cell

Know Table 11-2 p 319 Hormone class Major form in plasma Location of receptors Signal transduction mechanisms Rate of excretion / metabolism

Fig Adrenal Gland Part of Sympathetic Nervous System Steroids Catecholamines

Hormones of the Adrenal Cortex Glucocorticoids Mineralicorticoid Androgens DHEA “Andro” What regulates the secretion of cortisol and aldosterone?

Fig Gonadal Steroids (not adrenal cortex) King DS, Sharp RL, Vukovich MD, Brown GA, Reifenrath TA, Uhl NL, Parsons KA. Effect of oral androstenedione on serum testosterone and adaptations to resistance training in young men: a randomized controlled trial. JAMA 1999; 281(21): Estrogens

Fast if free Slow if bound Be able to give Examples. T4 to T3 and Testosterone to Estradiol Ex: Renin What happens to hormones once released?

Factors that affect hormone secretion Recall example: beta cells of Islets of Langerhans Secretion is usually pulsative, may be diurnal. Integrator! Na+, K+, Ca++, etc. NE, ACh, etc. TRH, TSH, DA, etc.

Fig Thyroid hormone stimulates production of beta-adrenergic receptors, which increases the target cell’s responsiveness to EPI. Permissive effect