Oxytocin/ADH/AVP

what part of the pituitary is it secreted from

posterior pit

• ADH/AVP too

Neurophysin I or II

Neurophysin II for oxy

Neurophsin I for AVP/ADH

What nuclei are oxytocin + ADH secreted from

supraoptic + paraventricular

What controls the release of oxyocin and AVP/ADH

Calcium (Gq)

How do estrogen and progesterone levels affect oxytocin?

High estrogen

Low progestone

@ end of pregnancy

Effect of oxytocin

milk ejection + uterine contraction

Gq GPCR receptor

Incr Ca

Phospholipase C

IP3 + DAG

PKC

AVP function

Water reabsorption (Incr water reabsorption + incr BP/ blood vol)

What are the types of diabetes insipidus + what causes it

Central DI: defiency in ADH

-pee a lot + thirsty (due to high plasma osmolality)

-polyuria + polydipsia

Nephrogenic DI: LOF of V2 receptors

• ADH levels could be normal or high, but V2 receptors aren’t working = can’t get AQP2 expressed = polyuria + polydipsia

• Insensitive to ADH

Neurogenic DI: head trauma/hypoxia/damage to cells that make ADH

Low ADH levels (head trauma = reduce ADH levels)

What regulated ADH/AVP

• Primarily: High plasma osmolality = (we need to take up more water)

• Others: Significant change in BP/ blood vol (needs to be > 10%)

Hows does ADH Deficiency (Central DI) affect:

plasma osmolality

electrolyte levels

ECF vol (same as ICF)

ECF osmolality (same as ICF)

• incr plasma osmoality

• Incr electrolytes (if plasma osmolality is high, then so is electrolyte)

• Low vol (we are losing water = peeing a lot)

• Incr ECF osmolality