Endocrinesystem

CO Mendivil

Feedback

Types of hormonal communication

Autocrine Paracrine

Endocrine

Intracellularreceptors

Chemical signalsAmines

Peptides, proteins

Lipids

Small molecules - ions

AdrenalineNoradrenaline

InsulinGHFSH

EicosanoidsSteroidsCannabinoids

Ca++

NOADP

Signal transduction

2nd messenger

Intracellularsignalling

Effector response

THE IMPORTANCE OF THE RECEPTORThe final effect depends on the RECEPTOR and the IC signal it raisesNot on the ligand

HO

HO

HC

H2C NH2

OH

Noradrenaline

a1 receptor

a2 receptor

b1 receptor

b2 receptor

b3 receptor

HRCont. strength

Lipólisis

Time matters

Circa dia: “Almost a day”Circadian: Repeated almost every 24 hrs

wikipedia.org

My head

A key locationPosterior pituitary

A key locationAnterior pituitary

TSH

ACTH

GH LHFSH

Prolactin Oxytocin

ADH(vasopressin)

Endocrine axes usually have 3 levels

1

2

3

http://www.ncbi.nlm.nih.gov/books/

Good sleep favours good growth

GH

Tumors of the anterior pituitary are relatively frequent

GH producing adenomas are acause of acromegaly

Symptoms of acromegalymay vary widely

The thyroid gland

Physiological role of iodine

Liquid and electrolyte balance

Basal metabolic rate

Cell turnover

Protein synthesis

Nutrient oxidation

Tissue differentiation

T4T3D1,D2

Physiological role of iodine

I-XXX

Physiological role of iodine

Brain development

Fetal and early postnatal period

Iodine defficiency: 1st cause of mental retardation worldwide

Physiological role of iodine

Recommended dietary intake

0 - 12 months

1 - 6 years

7 - 10 years

Adolescence-adulthood

Pregnancy-lactation

Age group

50 mg/d

90 mg/d

120 mg/d

150 mg/d

200-300 mg/d

RDI

Trace elements in human nutrition and health. Geneva: WHO,1996: 49-71

Advantages of iodine supplementation - USI

Documented reduction in goiter prevalence: China, Iran,Poland, Cameroon, Perú.

Children at risk of mental impairment due to iodine defficiency (worldwide):

1990=40 million1997=28 million

Documented shift upwards in the IQ of school children

Documented increase in yield of production of domesticlivestock

Drug Safety 2000;22:89-95

STRUCTURE OF BONE

Vitamin D

Cholecalciferol

OH

Cholesterol

7-dehydrocholesterolOH

Acetyl-CoA

HMG-CoA

Squalene

Lanosterol

Cholecalciferol

OH

CH2

Vitamin D comes from cholesterol

UV light

Colecalciferol

OH

CH2

OH

CH2

OH

25 OH-Colecalciferol 1,25 diOH-Colecalciferol

OH

OH

CH2

OH

24,25 diOH-Colecalciferol

OH

CH2

OH

OH

25,26 diOH-Colecalciferol

OH

CH2

OH

OH

OH

Vitamin D

Increases calcium ABSORPTION at the gut and REABSORPTION at the kidney

Regulates blood phosphate (reduces absorption)

Stimulates bone deposition

Inhibits bone RESORPTION

OSTEOCLASTS RESORB BONE MINERAL AND PROTEIN

REGULATION OF CALCIUM LEVELS

REGULATION OF CALCIUM LEVELS

VITAMIN D

RicketsConsequence of vitamin D deficiency early in life

Normal spongy bone

Osteoporotic spongy bone

Osteoporosis

The adrenal glandand the stress response

Steroid hormonesare derived

from cholesterol

Circadian Rhythm in ACTH and Cortisol

6am 6pm 6am

ACTH(pg/mL)

Cortisol(mg/dL)

1

15

5

20

Effects of cortisol (and corticosteroid drugs)

1. Increased plasma glucose 2. Inhibits bone deposition, promotes resorption3. Dampens inflammatory and immune responses4. Inhibits collagen formation5. Increases gastric secretions6. Promotes fluid retention

Excess cortisol producesCushing’ s syndrome

NEJM, Jan 31, 2008