Chemical Classification of Hormones continued

1
(No Transcript)
2
Chemical Classification of Hormones (continued)

• Glycoproteins
• Long polypeptides (gt100) bound to 1 or more
  carbohydrate (CHO) groups.
• __________________.

3
Hormone receptors
Cells of target organ have specific receptors for
hormones. Hormone binds to receptor and
stimulates a specific cellular response -
protein peptide hormones - receptor is in
____________________ - steroid hormones -
receptor is in ________ - prostaglandin hormones
- receptor is in _______________________
1.___________of receptors on or in cell regulate
degree of cell stimulation and cellular
response to the hormone 2. ______________ can
regulate whether there is a increase or
decrease in the number of receptors
Lack of _____________ receptor in male -
Testicular Feminization
4
Hormone Transport

• Transport mechanism depends on hormone
  ____________
• Protein hormones __________ carried in
  dissolved form
• Steroid Thyroid hormones _____________ have
  limited solubility in aqueous solution (plasma)
• These hormones ______ specific and nonspecific
  carriers
• Hormones must penetrate cell or bind to specific
  receptors ____________) to initiate action
• Are only about 1 of hormones are unbound

5
What is a 2nd messenger

• Some hormones __________ enter the cell
• Bind to receptors on cell membrane
• Hormone messenger
• _______________ relays info from the hormone to
  the inside of the cell

6
Hormones That Use 2nd Messengers

• Hormones that cannot pass through plasma membrane
  use 2nd messengers.
• ____________ __________ and glycoprotein
  hormones bind to receptor proteins on the target
  plasma membrane.
• Actions are mediated by 2nd messengers
  (signal-transduction mechanisms).
• Extracellular hormones are transduced into
  intracellular 2nd messengers.

7
Hormones That Bind to Nuclear Receptor Proteins

• Lipophilic steroid and thyroid hormones are
  attached to __________ carrier proteins.
• dissociate from ___________ and diffuse across
  membrane
• Receptors on nucleus for the lipophilic hormones
  are known as nuclear ______________.
• Complex binds with _____
• Activates genes mRNA Ribosome new or more
  protein (enzymes etc)

8
Steroid Hormones
Steroid Hormones Receptors are mainly in the
nucleus Glucocorticoids receptors are mainly in
the cytoplasm
Capillary
Steroid
Release from blood circulation
Progesterone
Uterine Glandular Epithelial Cell
Diffuses in cytoplasm
DNA
Rough Endoplasmic Reticulum
Steroid
Nucleus
Chromatin
Secretion
Protein Synthesis
mRNA
Receptor
Bilaminar Cell Membrane
9
What is a 2nd messenger

• 1. Adenylate Cyclase- cyclic AMP
• 2. Phospholipase C-Ca
• 3. Tyrosine kinase

10
Adenylate Cyclase-cAMP Table 11.4

• Polypeptide or glycoprotein hormone binds to
  receptor protein causing dissociation of a
  subunit of _______________.
• G-protein subunit binds to and activates
  adenylate cyclase.
• ATP cAMP PPi
• cAMP attaches to inhibitory subunit of protein
  kinase.
• Inhibitory subunit dissociates and activates
  protein kinase.

11
Adenylate Cyclase-cAMP (continued)

• ______________ enzymes within the cell to produce
  hormones effects.
• Modulates activity of enzymes present in the
  cell.
• Alters metabolism of the cell.
• cAMP inactivated by phosphodiesterase.
• Hydrolyzes cAMP to inactive fragments.

12
Ca2 2nd messenger system
2
1
3
6
4
Ca Calmodulin
See Table 11.5 7 Calmodulin activates protein
kinase 8 response to hormone
13
Epi Can Act Through Two 2nd Messenger Systems
14
Tyrosine Kinase

• Insulin receptor consists of 2 units that
  _________ when they bind with insulin.
• Insulin binds to ligandbinding site on plasma
  membrane activating enzymatic site in the
  cytoplasm.
• Autophosphorylation occurs increasing tyrosine
  kinase activity.
• Activates signaling molecules.
• Stimulate_______ _______ and ___________
  synthesis.

15
Tyrosine Kinase (continued)
16
Hypothalamus Pituitary Glands

• Hypothalamus control center
• Numerous autonomic nervous system control
  functions
• Hypothalamic releasing hormones
• travel to anterior pituitary
• Causes release of other hormones
• http//www.ansi.okstate.edu/resource-room/reprod/a
  ll/animations/ see HP Clip

17
Pituitary Gland

• Hypophysis or hypophysial gland
• Location___________ sella turcia (bone pocket)
• Structurally and functionally divided into
• Neurohypophysis pars nervosa or posterior lobe
• Adenohypohyysis pars distalis anterior lobe
• Communicates with hypothalamus

18
Pituitary Gland (continued)

• Posterior pituitary (neurohypophysis)
• Formed by down growth of the ______ during fetal
  development.
• Composed of axons with neural origin primarily
  from supraoptic and paraventricular nuclei of
  hypothalamus
• Mainly an extension of hypothalamus
• ______________ in hypothalamus
• Axons form stalk to the posterior pit
• Nerve endings in the actual lobe
• Nerve cell bodies in hypothalamus hormone
  source.
• Hormones carried down axoplasm into post pit
  stored until release

19
Pituitary Hormones (continued)

• Posterior pituitary
• Stores and releases 2 hormones that are produced
  in the hypothalamus ADH Oxytocin
• Antidiuretic hormone (ADH/vasopressin)
• Promotes the retention of H20 by the kidneys.
• Alcohol inhibits release of ADH increased
  urination
• Works to maintain blood pressure by regulation of
  water in blood
• Increases blood pressure via contraction of SM
• Stimulates glycogenolysis
• Increases water readsorption kidney nephrons
• Diabetes insipidus lack of ____________
  dilute urine excess amounts of urine (polyuria)
  and large amount of fluid intake (polydispsia)
• Diabetes Mellitus lack of ____________________
• Also large amounts of urine but urine contains
  large amounts of glucose

20
Pituitary Hormones (continued)

• Posterior pituitary
• Antidiuretic hormone (ADH/vasopressin)
• Receptors for ADH response
• _____________ in hypothalamus esophagus and
  stomach
• _____________receptors sense blood volume in
  atria of heart
• _______________ carotid sinus and aortic arch
• Sense pressure

21
Pituitary Hormones (continued)

• Posterior pituitary
• Antidiuretic hormone (ADH/vasopressin)
• Stimuli for ___________ release
• Osmotic pressure
• Decrease in blood volume (hemorrhage)
• Morphine nicotine barbituates
• Pain emotion stress exercise
• Stimuli that inhibit ADH release
• _________________ (both ADH Oxytocin)
• _________________

22
Pituitary Hormones (continued)

• Oxytocin
• Functions promote ____________
• Stimulates contractions of the uterus
  (myometrium) during parturition.
• Stimulates contractions of the mammary gland
  alveoli (myoepithelial cells) .
• _______________________ reflex.
• Prior to parturition ________________ of
  oxytocin receptors via other hormones
• If not would be running around lactating and
  having uterine contractions all the time.

23
Posterior Pituitary Oxytocin
Hypothalamus
Neural Pathway to Hypothalamus
Neuroendocrine Cells Synthesis Oxytocin
Nerve Cells
Spinal Cord

• Oxytocin
• stored in nerve terminal stimulation of nerve
  releases oxytocin in capillary
• contraction of myoepithelial cells for milk
  letdown
• - causes milk from Aveoli to release into
  glands
• Also causes
• - Stimulation of cervix at parturition
• - Clitoral and ejaculation response

Posterior Pituitary (Neurohypophysis)
Capillaries
Oxytocin Release in Blood
Calf Stimulation of Mammary Gland
24
Pituitary Gland (continued)

• Anterior pituitary
• Master gland (adenohypophysis).
• Derived from a pouch of epithelial tissue that
  migrates upward from the mouth.
• Consists of 2 parts
• Pars distalis ________________.
• Pars tuberalis thin extension in contact with
  the infundibulum.
• No neural connection between hypothalamus and ant
  pit.
• Under control of hypothalamic releasing hormones
• Primarily produce peptides (AA) except for
  _______________(catecholamine)

25
Pituitary Gland (continued)

• Anterior pituitary
• Releasing hormones synthesized by hypothalamic
  neurons
• Neurons terminate at the _________________
  (around portal vessles)
• AP down neurons release hormones into
  capillaries carried via portal blood vessels to
  ant pit.
• Hormones can be stimulatory or inhibitory

26
Pituitary Hormones

• Anterior Pituitary
• ____________effects
• High blood hormone causes target organ to
  hypertrophy.
• Low blood hormone causes target organ to atrophy.
• 6 different hormones released but all have
  similar affects

27
Pituitary Gland (continued)

• Anterior Pituitary
• 1. Growth Hormone (Somatotropin)
• 1. ____________ stimulates growth of body cells
  esp bone and muscle
• 2. Anabolism increases _________ transport
  into the cells
• Insulin like affect because insulin also causes
  not only glucose uptake but AA as well
• _________________ opposite of anabolism breaks
  cells down
• 3. Increases fat metabolism lipolysis
  (anti-insulin)
• Increases FFA levels in blood to provide energy
• Fasting stress
• When should you work out
• 4. Increases blood glucose
• 5. _________________ increases milk production

28
Pituitary Gland (continued)

• Anterior Pituitary GH
• 1.Young Animal Excess GH _________
• Increase in long bones
• Epiphyseal cartilage
• Continue to grow until puberty (how we know if a
  sheep is a lamb or mutton)
• Then no additional linear growth
• 2. After puberty ________ continual growth in
  areas which have responsive cartilage
• Jawbone hands face feet thick coarse skin
  muscle hypertrophy
• Lower GH ___________ decreased development
  no puberty or adult sexual development.

29
Pituitary Gland (continued)

• Anterior Pituitary ____________
• Increases mammogenesis pregnancy lactation
  following birth
• Decrease prolactin no lactation
• Fescue toxicosis cows horse sheep
• Decrease in prolactin especially problematic in
  horses

30
Prolactin

• Secreted from anterior pituitary
• In Mammals mammary gland development and milk
  production
• Receptors are everywhere
• Induces __________ growth in rabbit rodent
  humans. Maintains in dos rodents an skunks
• Chickens- depresses LH FSH causes broodiness
• Blocks GnRH stopping ovulation cycles

Dopamine
Stimulatory factors
(-)
()
Estrogen
()
Prolactin
Target Tissues
31
Pituitary Gland (continued)

• Anterior Pituitary Thyroid Stimulating Hormone
• Regulates size secretory activity of gland
• Cold stress ____________in TSH activity
• Decrease TSH activity __________
• Excess TSH activity hyperthyroidism

32
Pituitary Gland (continued)

• Anterior Pituitary Adrenocorticotropic hormone
  (ACTH)
• Stimulates outer portion of adrenal glands
  (__________)
• Adrenal cortex has 3 principal classes of
  hormones
• 1. _______________ cortisol and corticosterone
• 2. mineralocorticoids ______________________
• 3. androgens sex steroids
• Stress and hypoglycemia (low blood sugar)
  increase in ACTH

33
Pituitary Gland (continued)

• Anterior Pituitary Leutenizing hormone
• Stimulates _________________ ovary
• corpus luteum progesterone
• Follicle estrogen
• Maturation of____________
• Ovulation
• Formation of CL
• Both LH FSA maturation of graafian follicle
• Stimulates __________ secretion in males
  (interstitial cells of testes)

34
Pituitary Gland (continued)

• Anterior Pituitary Follicle stimulating hormone
  (FSH)
• _________ trigger promote development
• Stimulates follicle cells __________
• In males development seminiferous tubules
  maintenance of spermatogenesis
• Deficiency delayed _______ or amenorrhea
• Excess precocious puberty (less than 8 yrs old
  in humans less than 10 in males)

35
Hypothalamus-Anterior Pituitary interrelationship

• ________________ portal system caries
  hypothalamic hormones specifically to the
  anterior pituitary without dilution in the
  systemic blood.
• 1. Allows rapid response
• 2. Little dilution of peptide hormones
• 3. Peptide hormones have short 1/2 life
• Specific hypothalamic nuclei secrete releasing
  or release
• inhibiting factors that control release of
  pituitary hormones.

36
Hypothalamic Control of Posterior Pituitary

• Hypothalamus neuron cell bodies produce
• ADH supraoptic nuclei.
• Oxytocin paraventricular nuclei.
• Transported along the hypothalamo-hypophyseal
  tract.
• Stored in posterior pituitary.
• Release controlled by neuroendocrine reflexes.

37
Hypothalamic Control of the Anterior Pituitary

• Hormonal control rather than neural.
• Hypothalamus neurons synthesize releasing and
  inhibiting hormones.
• Hormones are transported to axon endings of
  median eminence.
• Hormones secreted into the hypothalamo-hypophyseal
  portal system regulate the secretions of the
  anterior pituitary

38
Question

• Does the posterior pituitary produce any
  hormones
• NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

39
Mechanism of Thyroid Hormone Action

• Thyroxine (tetraiodothyronine) T4
• Travels attached to ____________
  (thyroxine-binding globulin)
• Small amount of __________
• Carrier proteins have a ___________affinity for
  T4
• Free T3 is what is physiologically active
• So why do we have T4
• T4 passes into cytoplasm and is converted to T3.
• Receptor proteins located in nucleus.