recent posts

04. Anterior Pituitary Hormones (Hypothalamus & Pituitary) III

 

Anterior Pituitary Hormones-Pharmacological use

image

 

 

FSH

LH

  • Stimulates oogenesis & spermatogenesis
  • Prepare from urine post menopausal women
  • Lack, due to pituitary GnRH↓ lead to  infertility
 
   

  • Secret by placenta & taken from urine of pregnant mother

Lack due to pituitary ↓GNRH,lead to Infertility(both sexes)

Use to treat

  • Crypto-orchidism [unsdesend testes]
  • Precipitate puberty in males when delayed In hypogonatropic hypogonadism (↓Testosterone due to ↓Gonadotropin → 2nd ry sexual characteristics)

HCG has similar  action to LH

  •         In female (+ )→Progesterone
  •         Male (+ )→ Testosterone

ACTH

  1. From ant.pit
  2. Synthetics are available -non allergic/dis advantage IM injection pain
  3. Similar to steroids
  4. Use in, diagnosis
  5. Therapy- myochronic epilepsy , RhD arthritis

GH  ( separate lecture ) ( click here )

Posterior Pituitary Hormones

 

image

 

  • They are produced in the hypothalamus, and carried by axo-plasmic flow
    1. ADH (Vasopressin)
    2. Oxytosin

ADH

  • Mainly acts on V2 receptors in CD and insert Aquaporin II water channels to P cells
  • Regulates blood pressure
  • Decrease hemorrhages
  • Increase glycogenolysis in liver
  • Increase ACTH secretion from anterior pituitary

image

 

Factors affecting ADH secretion

 

Increase ADH secretion

Decrease ADH secretion

  1. Elevated plasma osmotic pressure
  2. Decreased ECF volume
  3. Pain, emotion, stress exercise
  4. Nausea, vomiting
  5. Standing
  6. AT II
  1. Decreased plasma osmotic pressure
  2. Increased ECF volume
  3. Alcohol

 

Complications

ADH excess

ADH insufficient

SIADH

  • Water retention

Stimulate Aldosteron secretion

  • Loss of salt in urine

Poly urea(DI)

Cranial DI

    • Problem at brain level,
    • Lack of ADH

Nephrogenic DI

  • ADH level is normal, but insensitive to kidney

 

 

 

ADH Preparations

1.ADH(Vasopressin) For cranial DI

2.Lypressin

3.Desmopressin(DDAVP) No vasoconstriction,Longer duration of action,can give SC,orally & intra-nasally

  • DDAVP is better than ADH

Use for ,

1) Cranial DI

2) Haemophilic-factor 7

3) Nocturnal enuresis in children

4) Bleeding –Oesophegeal varices

5) Vasoconstrictor in local anesthesia

 

Side effect

 

Coronary vessels –angina

Abdominal vessels –Cramps

 

Oxitosin (Syntosinon)

 

 

↑Uterine contraction

 

Use for

  • Induce labour ,when uterine contraction is not adequate
  • Combine with ergometrine (syntometrine )→to be use in PPH(post partum hemorrhage)

 

Pituitary  insufficiency causes

  1. Adrenal gland hypotrophy
  2. Reduced FSH & LH
  3. Reduced ACTH (absent of stress induced Aldosteron secretion)
  4. Stress sensitive
  5. Reduced growth
  6. Reduced thyroid function
  7. Reduced ADH
  8. Hypoglycemia
    • Isolated GH deficiency is rare in adults

profile editor"It will take only 2 sec to say thanks and will take only 10 sec to write a comment it will be a nice encouragement for uploaders "

04. Anterior Pituitary Hormones (Hypothalamus & Pituitary) III 04. Anterior Pituitary Hormones (Hypothalamus & Pituitary) III Reviewed by Radiology Madeeasy on April 10, 2010 Rating: 5
Powered by Blogger.