Bio 337 Common hormones and their location

Intracrine mediation

Cell moving chemicals around inside itself

autocrine mediation

Cell moves chemicals out, but moves them back in at different point in the cell

paracrine mediation

Cell moves chemicals to another cell, normally they are neighboring cells

endocrine mediation

Sends a hormone through the bloodstream, picked up by another cell receptor

exocrine mediation

sends a chemical into a space into the body not bloodstream

Protein hormones

Peptide hormones

Large

Soluble in blood - no carrier protein necessary

Stored in endocrine cells

Fast acting

Short half-life

Peptide hormones

Small comprised of a cholesterol subunit

Not soluble in blood - must bind to a carrier protein

Not stored - produced on site at the time - can just go through cell membrane

Slow acting - hours to days

Long biological half life

Amine hormones

Derived from a single amino acid

Not soluble in blood - needs carrier protein

Catecholamines - adrenal medulla derived from tyrosine

Indole amines - pineal gland

Steroid hormones examples

Glucocorticoids, Androgens, Estrogens, Progestins

Actions of steroid hormones

Steroid hormones go through the cell wall and can bind to the receptor

This starts its process immediately

Hormones receptor complex transcribes DNA into RNA

mRNA translates to amino acids

Steroid hormones lead to changes in gene express over the course of hours or days

Peptide hormones examples

Hypothalamic hormones, Antuitary pituitary hormones, Posterior pituitary hormones, Pancreatic hormones

Peptide hormone action

Receptors must be in the cell membrane as it can't go through it

Signal transduction

When receptor is bound to, it phosphorylates the g protein

This then releases cAMP converted from ATP

MapK -> MapKK -> MapKKK

This activates phosphorylase which can break apart glycogen into glucose

mapKKK can activate Creb (transcription factor) which makes phosphetase

Amine examples

Catecholamines, Indole amines

Pineal Gland

Secretes melatonin - amine hormone

Thyroid and parathyroid

T3 & T4

Adrenal glands

Cortex (steroid hormones)

• Cortisol

• Corticosterone

• Aldosterone

• Weak androgens - DHEA

Medulla (catecholamines)

• Epinephrine

• Norepinephrine

• Dopamine

Pancreas

glucagon, insulin, somatostatin, pancreatic polypeptide

Testes

DHT, Testosterone

Ovaries

Estradiol, Estriol, Estrone, Progesterone

Hypothalamus

Corticotropin-releasing hormone (CRH)

• Gonadotropin-releasing hormone (GnRH)

• Thyrotropin-releasing hormone (TRH)

• Growth hormone-releasing hormone (GHRH)

• Somatostatin

• Dopamine

Posterior pituitary

Vasopressin, oxytocin

anterior pituitary

Acts on other glands

Adrenocorticotropic hormone (ACTH)

• Gonadotropins (LH, FSH)

• Thyroid-stimulating hormone (TSH)

acts on other targets

• Growth hormone (GH)

• Prolactin