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Summary - Geneesmiddelen van het endocrien systeem.
1 College 1: Introduction
Endocrinesystem plays an important role in:Autonomic body functions Communicationbetween cells and organs
Autonomic body functionsFunctions that are aimed at the continued existence of the individual and the species.
Communication between organs and cell systems is important for:- autonomic nervous system (relatively quick)
- hormones (relatively slow)
- interaction between these systems (neuroendocrine cells)
Endocrine regulation examples- metabolic functions (energy homeostasis and growth)
- functioning of the immune system
- regulation of the internal environment (water homeostasis and electrolyte homeostasis: blood circulation, bone homeostasis)
Types of endocrien regulations-Neuronà Quick system (interaction between neuron and target cell, noradrenaline or acetylcholine are the neurotransmitters).
-Neuroendocrine hormone àSlow system
(release in the blood)
Endocrine gland hormones are:A special type of cells.
Pancreases introduce:Insuline and it can work autocrine or paracrine or endocrine.
AutocrineInfluence the own cell
ParacrineInfluence the neighbor cells
EndocrineInfluence the organ
The endocrine system is a system where there is communication between:The hypothalamus and the pituitary gland. These releases or inhibit hormones.
HypothalamusReleasing or inhibiting hormones
PituitaryglandTSH ACTH FSH
Peptide hormones and protein hormones
Membrane receptors-Relatively quick
-G-protein coupeld receptors (adenylyl cyclase, PI metabolism)
Steroidhormones, sterols, thyroxine derivatives
(Intracellular receptors)Adrenal gland
Calcitriol (vit D derivaten)
Intracellular receptors-Relatively slow
-Regulation of protein synthesis (Ligand-gated transcription factors)
Thyroid gland T3 and T4 working via:
Intracellular receptors, but are dependent on G-protein coupled receptors(membrane receptors).
Endocrine Hormones- Oftenanalogues: stable agonists/antagonists
(substituted by analogues)
hormones = Tropic hormonesInfluence a lot of metabolic parameters in our body.
Parentral more stable effector than can be administerd orally.
Low bioavailibility via oral.
Pharmaceuticals can affect:-Hormone synthesis
Bioactive compounds/HormonesMetabolically instable--> And thus stable agonist or antagonists are synthesites
Effector hormonesLike anti-diuretic hormones --> Are administered orally.
Treatment easier by synthetic steroids and thyroxine derivatives.
Hypothalamic-pituitary systemIn the hypothalamus (upper part) are the neuroendocrine cells which synthesise the hormones.
Released to the bloodstream to the pituitary.
Anteriorpituitary (Veins) frontHere are endocrinesystem--> produce hormones
(these are released to the blood and act on a specific target organ)
Hormones from the hypothalamus regulate the release of hormones by the anterior pituitary
Releasing factors (RF) or hormones (RH)
Inhibitin factors (IF) or hormones (IH)
PosteriorPituitary (Arteries) backGreen neuroncells in the hypothalamus synthesing posterior pituitary hormones.
From the left side of the
hypothalamusto the right side of the pituitary.
Here is the production of ADH and oxytocine release. --> directly to the bloodstream.
Hypothalamus and Pituitary regulationHypothalamus and pituitary gland together regulate a major part of the endocrine system.
Hypothalamus functionIt converts nerve impulses from the brain into a hormonal impulse.
Of how many parts is pituitary gland made? And what are they?3 parts
Anterior (anterior lobe)
Pars intermedia (barely present in humans)
Posterior (posterior lobe)
Neuron cells (purple)Neurons synthesing tropic hormones (right of the hyothalamus).
TRHThyroid Releasing Hormone
CRHCorticotropin releasing hormone
GHIHGrowthHormone Releasinh Hormone
GrowthHormone Inhibiting Hormone (Somatostatin)
Released by the hypothalamus--> Act on the interior pituitary --> Force the release of GH in the pituitary.
Hormone release schemeGH-->Liver-->Somatomedins
ACTH-->Adrenal cortex-->Glucocorticoids, mineralcorticosteroids, androgens.
LH-->Estrogen, Progesteron, Testosteron
Negative feedback mechanismThe somatomedins released by the liver can have a negative effect on the release of GHRH in the hypothalamus.
In the posterior lobe
Antidiuretic system is the same as vasopressine
Working in the kidney (homeostasis of ion and water.
OxytosineProduction of the--> Milk
Contraction of the-->Uterus
Influence on the-->mooth
ADH and Oxytosine work via:G-Protein Coupled receptors
Hypothalamic hormones-Are peptides (except dopamin)
-Transport to the anterior pituitary is via the bloodstream.
-Neurohormones--> Because their release is regulated by neurons.
Hormones SizeHypothalamic hormones = Small peptides.
Pituitary hormones = Large peptides/proteins
Action between GH and TSHGH down-->
TSHdown-->(Insulin down, Glucagondown)
The hormones have influence on the energy load (
metabolicload) and growth (depending on the amount of glucose).
Influence level of glucose and lipids.
Anterior pituitary hormone groups
Species-selective (amino sequence)
No binding to sugar
LH,FSH, TSH, CG
Bind to sugar 23-33% of the total structure
Complex, alfa and beta chain.
Group3 Derived from precursor protein (pro-opiometianocortin)
ACTH, alfa-MSH, beta-LPH
No sugar like group 1
Molecular weight MW is the lowest of all gruops
Glycoproteins (Group 2)Glycoproteins are made up of an alfa-subunit and a beta-subunit.
alfa-subunits are virtually identical, contain 2 oligosaccharides chains that are boound via asparagine
beta-subunits have the specific biological effect and contain 1 or 2 oligosaccharide chains.
Pro-opiomelanocortin (Group 3)Interesting precursor
Multiple hormones are produced from a large precursor molecule by enzymatic cleavage (proteases) in various tissues.
ACTH and beta-lipotropin are formed in the anterior pituitary
alfa-MSH is split off in the pituitary pars intermedia (pigmentation).
are formed in the brain.
Latest added flashcards
Insuline-like Growth Factor-1 (IGF-1)
ELISION=Shortening the chain by removing an amino acid INTERCALATION=Lenthening the chain by inserting an amino acid. (increase stability of an alfa helix and particullary beta sheets)
- Changing the side chain=Changing an amino acid.
- Replacing an
L-aminoacid by a D-aminoacid (the opposite, for the metabolic activity stability)
- Blocking an end group.
S-Sbridges by ethylene bridges or by CH2bonds.
- Endogenous peptides are often metabolized quickly.
- Knowledge of the amino acid sequence and characteristics of a peptide creates oppertunities to develop new analogues with -Increased stability
- Fewer side effects
- Pharmacological activity of analogues provides insight into the
structure-activity relationship (SAR)
Such a protein is usually made up of two chains (alfa and beta subunit) with cysteine amino acids that are connected via disulfide bridges.
The final dimantional structure of a protein.
Defining the interaction of the hormone and the biological activity.
- Electrostatic or ionic bonds
- Van der Waals force
- Hydrogen bonds
In an a-helix, the C=O group of amino acid n is bound to the N-H group of amine acid n+4 via a hydrogen bond.
Coiled coil structure
Beta-sheets = boundaries between peptides which are characterized by the interaction of hydrophobic course. (give the protein more stabilty and define the biological function of the protein structure and thus hormone structure)
Hydrogen bonds between stretched chains
Ant-parallel and Parallel.
- Primary = Order of amino acids and presence of dissulfide bridges
- Secundary = The spontaneous folding of certain regions during synthesis, leading to the formation of a-helix or B-sheets
- Teritary = Spatial organization of regions located far apart, such as combinations of helices and sheets
(complete chain structure)
The importance of the biological activity
- Quanternary = Spatial organization in proteins with multiple peptide chains
Protein structure is mainly determined by the side chains in the amino acids