Download MBBS Hormone 1 Lecture PPT

HORMONES

o Term hormone was introduced by Starling and

--- Content provided by FirstRanker.com ---

Bayliss in 1905.

o Hormones are the chemical messengers produced by

endocrine gland and transported by blood to other

--- Content provided by FirstRanker.com ---

tissue or organ where these stimulate a change in

some metabolic activity.

--- Content provided by FirstRanker.com ---

o They are produced from by one type of cell and have

regulatory effect on the activities of other type of cell

or on itself.

--- Content provided by FirstRanker.com ---

o The tissue or organ stimulated by a specific hormone

are called Target Tissue/ Target organ

--- Content provided by FirstRanker.com ---

o .

Hormones act on specific cells and organs called

--- Content provided by FirstRanker.com ---

target cell or target organ.

o Target cell or organ is that cell which has specific

--- Content provided by FirstRanker.com ---

receptors for the hormone which bind to them

with or without any demonstratable biochemical

or physiological response

--- Content provided by FirstRanker.com ---

o Concentration of hormone is very low in blood

but..

--- Content provided by FirstRanker.com ---

o Presence of receptors on target tissue
Specific binding between hormone and receptor
Very high local concentration
o Makes the target tissue highly specific to

--- Content provided by FirstRanker.com ---

hormones
CLASSIFICATION OF HORMONES BY

MECHANISM OF ACTION

--- Content provided by FirstRanker.com ---

I. Hormones that bind to intracellular receptors

1. Androgens
2. Calcitriol (1,25[OH]2-D3)
3. Estrogens

--- Content provided by FirstRanker.com ---

4. Glucocorticoids
5. Mineralocorticoids
6. Progestins
7. Retinoic acid
8. Thyroid hormones (T3 and T4)

--- Content provided by FirstRanker.com ---

II. HORMONES THAT BIND TO CELL SURFACE

RECEPTOR

A. The second messenger is cAMP

--- Content provided by FirstRanker.com ---

? 2-Adrenergic catecholamines
? -Adrenergic catecholamines
? Adrenocorticotropic hormone (ACTH)
? Antidiuretic hormone (vasopressin)
? Calcitonin

--- Content provided by FirstRanker.com ---

? Human Chorionic gonadotropin, (HCG)
? Corticotropin-releasing hormone
? Follicle-stimulating hormone (FSH)
? Glucagon
? Luteinizing hormone (LH)

--- Content provided by FirstRanker.com ---

? Melanocyte-stimulating hormone (MSH)
? Parathyroid hormone (PTH)
? Somatostatin
? Thyroid-stimulating hormone (TSH
B. The second messenger is cGMP

--- Content provided by FirstRanker.com ---

? Atrial natriuretic factor
? Nitric oxide
C. The second messenger is calcium or

--- Content provided by FirstRanker.com ---

phosphatidylinositols (or both)
? Acetylcholine (muscarinic)
? 1-Adrenergic catecholamines
? Angiotensin II
? Antidiuretic hormone (vasopressin)

--- Content provided by FirstRanker.com ---

? Cholecystokinin
? Gastrin
? Gonadotropin-releasing hormone
? Oxytocin
? Thyrotropin-releasing hormone (TRH

--- Content provided by FirstRanker.com ---

D. The second messenger is a kinase or phosphatase

cascade

? Adiponectin

--- Content provided by FirstRanker.com ---

? Chorionic somatomammotropin
? Epidermal growth factor (EGF)
? Erythropoietin (EPO)
? Fibroblast growth factor (FGF)
? Growth hormone (GH)

--- Content provided by FirstRanker.com ---

? Insulin
? Insulin-like growth factors I and II
? Leptin
? Nerve growth factor (NGF)
? Platelet-derived growth factor

--- Content provided by FirstRanker.com ---

? Prolactin


HORMONES

--- Content provided by FirstRanker.com ---

STIMULUS
PROPERTY

GROUP I

--- Content provided by FirstRanker.com ---

GROUPII

1.HORMONES

Adrenal steroids, thyroid Hypothalamic

--- Content provided by FirstRanker.com ---

hormones,

hormones, sex hormones, pituitary

--- Content provided by FirstRanker.com ---

hormones,

calcitriol ,retinoids

pancreatic

--- Content provided by FirstRanker.com ---

hormones,

Adrenal hormones

--- Content provided by FirstRanker.com ---

2.Chemical nature

Steroids,

iodothyronines, Peptides & polypeptides,

--- Content provided by FirstRanker.com ---

retinoids

proteins,

--- Content provided by FirstRanker.com ---

glycoproteins,

Catecholamines

3.Solubility

--- Content provided by FirstRanker.com ---

Hydrophobic,

Water Hydrophilic Water soluble

--- Content provided by FirstRanker.com ---

insoluble

4.Transport Protein

Required

--- Content provided by FirstRanker.com ---

Not required

5.Receptors location

--- Content provided by FirstRanker.com ---

Cytoplasm and nucleus

Cell membrane

6.Mediators of action

--- Content provided by FirstRanker.com ---

Hormone

-Receptors cAMP

--- Content provided by FirstRanker.com ---

Complex

cGMP
Ca ++
Phosphoinositides,

--- Content provided by FirstRanker.com ---

kinase Cascade etc.
SUBCLASSIFICATION OF GROUP II.A HORMONES

Hormones That Stimulate Hormones

--- Content provided by FirstRanker.com ---

That

Inhibit

--- Content provided by FirstRanker.com ---

Adenylyl Cyclase (HS)

Adenylyl Cyclase (HI)

--- Content provided by FirstRanker.com ---

ACTH

Acetylcholine

--- Content provided by FirstRanker.com ---

ADH

2-Adrenergics

-Adrenergics

--- Content provided by FirstRanker.com ---

Angiotensin II

Calcitonin

--- Content provided by FirstRanker.com ---

Somatostatin

CRH

--- Content provided by FirstRanker.com ---

Glucagon

--- Content provided by FirstRanker.com ---

TSH