endocrine exam 2

GH is made by?

Somatopes

Somatopes are?

Acidophilic

How many amino acids in GH?

191

Secretion Pattern of GH?

Pulses, stronger when asleep, fasting, and excersising - lower with age

How many amino acids in GHRH?

44

What does GHRH do?

Stimulates and makes pulses

How many amino acids in Somatostatin?

14

What does Somatostatin do?

Inhibits GH, keeps low between pulses

Where does Gherelin come from?

Stomach

What does Gherelin do?

Stimulates GH as well as makes you hungrier

Galanin, GABA, α2-adrenergic and dopamine signals do what?

Stimulate GHRH

Acetylcholine and serotonin do what?

Inhibit Somatostatin

β2-adrenergic signals and CRH do what?

Stimulate Somatostatin

What creates negative feedback?

Liver IGF-I and free fatty acids

Direct actions of GH?

Lipolysis, protein anabolic, diabetogenic (anti-insulin) METABOLIC!

Indirect actions of GH?

growth and chondrogenesis ANABOLIC!!

Where do the indirect actions of GH actually occur?

Epiphyseal plate

Gigantism?

Too much GH in kids

Acromegaly?

Too much GH in adults

Short Stature?

Too little GH in kids

What does GH do for fish?

Promotes seawater adaptation, and parr-smolt transformation

What receptor is GH? TEXTBOOK

Cytokine-type, JAK/STAT

What is Prolactin?

Acidophillic, Lactotropes

How many actions of Prolactin?

Over 300

Pattern of Prolactin secretion?

Episodic and more in sleep

Mammal actions of Prolactin?

Mammary development, lactogenesis (casein), maintains corpus luteum in some mammals

Other vertebrate actions of Prolactin?

Crop sac milk and brood patch (birds), discus milk, Na+ retention in freshwater fish, water drive in newts, anti-metamorphic in tadpoles, nesting and maternal behavior, reptile skin sloughing and tail regeneration.

Prolactin is held back constantly by what?

Hypothalamic dopamine

Dopamine neurons are stimulated by

Glutamate, acetylcholine

Dopamine neurons are inhibited by

Histamines and Opioids

What are the releasing factors of Dopamine?

Oxytocin, VIP, TRH, estradiol

What are the releasing factors activated by?

Serotonin

Where does the Estrogen act?

The pituitary

Suckling does what?

Releases prolactin through a reflex

What is Hyperprolactinemia?

Most common pituitary tumor

What does Hyperprolactinemia cause in women?

Galactorrhea and amenorrhea (women)

What does Hyperprolactinemia cause in men?

Hypogonadism, infertility and erectile dysfunction

What is Hyperprolactinemia caused by?

Lowered GnRH, FSH and LH

What drugs raise prolactin?

Reserpine, clozapine, olanzapine, opiates

What drug can treat raised prolactin?

Bromocriptine (dopamine agonist) or other Alkaloid

What does prohormone mean?

Big hormone can split into smaller hormones

POMC can split into what?

ACTH and a-MSH

What is the latin term associated with Corticotropes?

Pars Distalis

What is the latin term associated with Melanotropes?

Pars Intermedia

What Prohormone Convertases are in Corticotropes?

PC1/PC3

What Prohormone Convertases are in Melanotropes?

PC2 (or PC1/PC3 plus PC2)

PC1/PC3 cut POMC into what?

ACTH and β-LPH

PC2, or PC1/PC3 plus PC2, cut POMC into what?

α-MSH, β-endorphin, CLIP (corticotropin-like peptide) and γ-LPH

Which products by Melanotropes have unknown functions?

β-MSH and γ-MSH

How many amino acids in α-MSH?

13

Human tanning comes from UV and what?

Skin-made MSH or ACTH

Where are Melanophores located?

Dermis

What is inside Melanophores?

Melanosomes

What is inside Melanosomes?

Melanin (Black, Brown, Yellow, Red)

What are pigment cells called?

Chromatophores

Xanthophores

Yellow

Erythrophores

Red

Iridophores

Reflective, Iridescent

Leucophores

White

Cyanophores

Blue

What does α-MSH do?

Disperses melanin, darkening the skin, can change color in seconds

How many melanocortin receptors and what are they coupled with?

5

MC1R binds what?

MSH

MC2R binds what?

ACTH

MC1R raises what?

cAMP

What are melanocortin receptors coupled with?

G-proteins

How fast does color change in cold-blooded animals?

Seconds to minutes

How fast does color change in warm-blooded animals usually?

Seasonal

MC1R loss of function does what?

Red or yellow hair, light skin

MC1R gain of function does what?

Black hair

How is color regulated?

Tonic inhibition by dopamine and background color