3. TABLE OF CONTENTS
Classes of
hormones
Synthesis &
processing of
hormones
Degradation of
hormones
1
3
2
4. 1. Amino acid derivatives
Tyrosine
a. Thyroid hormones
b. Dopamine
c. Catecholamine
Tryptophan
a) Serotonin
b) Melatonin
2. Small Neuropeptides
a) GNRH
b) TRH
c) Somatostatin
d) vasopressin
Classes of hormones
5. 3. Large neuropeptides
a) Insulin
b) LH
c) PTH
4. Steroid hormones
Adrenal cortex
a) Mineralocorticoids – aldosterone
b) Glucocorticoids – cortisol
c) Adrenal androgens- androstenedione& hydroepiandrosterone
sulphate
Gonadal
a) Testosterone
b) Oestrogen
c) Progesterone
12. DEGRADATION OF HORMONES
HALF LIFE
• hormones are synthesised in such a way that their half life coincides
with duration of action
Example: Hormone transport and degradation dictate the rapidity with
which a hormone signal decays some hormone signals are evanescent
example somatostatin whereas others are longer lived example TSH
because somatostatin exacts effects in virtually every tissue a short half
Life allows it's concentrations and actions to be controlled locally structural
modifications that impair somatostatin degradation have been useful for
generating long acting therapeutic Analogues such as octreotide in
contrast the actions of TSH are highly specific for the thyroid tissue it's
prolonged half life accounts for relatively constant serum levels even
though TSH is secreted in discrete pulses
13. • Hormone degradation can be an important mechanism for regulating
concentrations locally as noted above 11 beta hydroxy steroid
dehydrogenase inactivate glucocorticoids in renal tubular cells
preventing action through the mineralocorticoid receptor thyroid
hormone deiodinases convert t4 to t3 and can inactivate t3 during
development degradation of retinoic acid by cyp26 b1 prevents
primordial germ cells in the male from entering meiosis as occurs in the
female ovary
16. Receptors for hormones
• Receptors for hormones are divided into two major classes:
membrane and nuclear
• Membrane receptors primarily bind peptide hormones and
catecholamines
• Nuclear receptors bind small molecules that can diffuse across
the cell membrane
• Hormones bind to receptors with specificity and affinity that
generally coincides with the dynamic range of circulating
hormone concentrations
18. GPCRs
• Seven transmembrane GPCR family binds to remarkable array of
hormones including large proteins , small peptides, catecholamines
and even minerals
• The transmembrane spanning regions are composed of hydrophobic
alpha-helical domains that transverse the lipid bilayer .
• Hydrophobic pockets
• Hormone binding causes confirmational change transducing
structural changes to intracellular domain
20. GPCRs - endocrinopathies
• Mutations in the GPCRs result in the alteration of their interaction with
G proteins
• Patient presentations resemble – glandular failure syndromes
21.
22. Tyrosine kinase receptors
• Transduce signals for insulins and variety of growth factors
• Cysteine rich extracellular domains contains binding sites for growth
hormones
• Binding autophosphorylation interacts with intracellular adaptor
proteins
24. Serine kinase receptors
• Actions of activins , TGF, Mullerian inhibiting substance and BMP’s
• This family of receptors consists signals through proteins termed as
SMADs
• Like STAT proteins – serves dual role of signal transducer and
transcripting factor
26. ENDOCRINE SYSTEM Functions
Mercury is the
smallest planet
Metabolic
Mars is a very
cold planet
Growth
Neptune is far
from the Sun
Fertility
Earth is where
we all live
Emotions
Jupiter is the
biggest planet
Sleep
27. CREDITS: This presentation template was created
by Slidesgo, including icons by Flaticon,
infographics & images by Freepik
THANK
YOU!
