bimimetik

MOLECULAR EVEN OF OLFACTORY

6. cAMP open ligand-gated (cAMP gated) sodium channels → Na+ influx

7. Na+ influx lower plasma membrane potential (depolarization)

6. When depolarization reaching threshold

7. Action potential proceed

8. Action potential continue and transmitted along the olfactory nerve to the brain

9. Brain respone to the olfactory signal and processed to become smell perception

1. Sensory neurone cillia is submerged in mucus layer. Odorant molecule dissolved in the muccus

and

2. Bound to a 7-pass transmembrane protein receptor within cillia

3. Activate G protein of the receptor (at the sitoplasm site)

4. Active G protein then activate adenylil cyclase at the plasma membrane of cillia

5. Active adenylil cyclase catayze the convertion of ATP to cAMP within cytosol

MOLECULAR EVEN OF OLFACTION/ODORANT

Actions of salty, sour, bitter and sweet substances on their respective receptor systems

• Some tastants simply enter the receptor cell through channels as ions. For example, salty substances often contain sodium ions. These sodium ions can simply enter the receptor cell through sodium or cationic channels. Sour substances are acidic. The hydrogen ions can enter cells through cationic channels.

• Other tastants can compete for use of potassium channels, thereby reducing outward potassium currents (this would result in hypopolarization). For example, bitter substances like quinine can block the potassium channels, leading to hypopolarization

• Still other tastants work through second messengers to close potassium channels, reducing potassium current. Both bitter and sweet substances act in this way.

• A final group of tastants act through second messengers to open chloride or non-specific ion channels

GENERAL TASTE SIGNALING

MHC CLASS I BINDS ENDOGENOUS ANTIGEN

Activation phase

Effector phase

Cytokines

Cytotoxic

T cell

(Killer T

cell)

Cytotoxic T cell divide

Produce perforin Kill infected cell

MHC Class II binds exogenous antigen

It works by stopping a specific enzyme (known as acetylcholinesterase) from breaking down acetylcholine in the brain. Acetylcholine is a chemical that aids in many brain functions, including memory, attention, reason, and language These medications also work by increasing the levels of acetylcholine in the brain which mayhelp reduce the symptoms of dementia in patients with Alzheimer disease.

How Do The Medicines Work?

How the positively charged nitrogen in the acetylcholine molecule is attracted to the ionic site on acetylcholinesterase, and hydrolysis is catalyzed at the esteric site to form choline and acetic acid.

How Acetylcholinesterase Normally Works

Acetylcholine (A) diffuses from presynaptic nerve ending across synaptic cleft to acetylcholine receptor on postsynaptic neuron. Most of the released acetylcholine is hydrolyzed by cholinesterase (C) before it crosses the cleft. Donepezil (D) blocks cholinesterase's ability to hydrolyze acetylcholine, increasing the fraction of released acetylcholine that migrates all the way across the synaptic cleft to acetylcholine receptors. This enhances cholinergic transmission. Tolterodine (T) is a muscarinic receptor antagonist that blocks acetylcholine's actions on muscarinic cholinergic receptors and decreases cholinergic transmission.

ANTIANDROGEN

• Androgen merangsang produksi sebum. Untuk menghilangkan acne, wanita

harus menggunakan antiandrogen;

• Pil KB bekerja dengan meregulasi hormon, menghambat efek dari androgen

sehingga mengurangi produksi sebum.

Source: Pharmacological profiles of progesterone, drospirenone and other synthetic progestogens.

Foldert et al. Eur J Contracept Reprod Health Care 2000; 5: 124-34

Brand name: Diane

CYPROTERON ACETATE (CPA)

Rumus Molekul : C24H30Cl2O4

Rumus Molekul : C21H30O2

PROGESTERON

CARA KERJA CPA

CPA Merupakan Hormon Sintetis

secara kompetitif

Menurunkan Kadar Androgen Bebas

Menduduki Reseptor Androgen

Mengurangi Produksi Sebum Pada Kulit

Mencegah Acne

Mekanisme Kerja CPA

Basic nerve cell (neurone) structure

Sensory neurones

Carries impulses from

receptors e.g pain receptors

in skin to the CNS( brain or

spinal cord)

Relay neurones

Carries impulses from sensory

nerves to motor nerves.

Motor neurones

Carries impulses from

CNS to effector e.g.

muscle to bring about

movement or gland to

bring about secretion of

hormone e.g ADH

The functions of various neurones

Impulses from sensory neurones

Impulses to other neurones

Cell body with nucleus

Main relay fibre

Direction flow of nerve impulses

Rec

epto

r

Sensory fibre Axon fibre

Direction flow of nerve impulses


Impulses to CNS

Impuls

es f

rom

CN

S


Axon fibre

Direction flow of nerve impulses Effector (muscle or gland

- - - - - - - - - - - - - - - - - -

+ + + + + + + + + + + + + + + + + +

axon axon

synapse

presynapse postsynapse

- + + + + + + + + + + + + + + + + +

- - - - - - - - - - - - - - - - - +

+ - + + + + + + + + + + + + + + + +

+ - - - - - - - - - - - - - - - - -

+ + - + + + + + + + + + + + + + + +

- + - - - - - - - - - - - - - - - -

+ + + - + + + + + + + + + + + + + +

- - + - - - - - - - - - - - - - - -

Na+

K+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

-

+

outside the cell

inside the cell

+ + + + - + + + + + + + + + + + + +

- - - + - - - - - - - - - - - - - -

Na+, relatively more positive than K+

Normal condition → charges are polarized → resting potential

Signal transfer within axon

Ach receptors are

unoccupied and closed

Ach receptors are

occupied and open

Acetylcholine

SISTEM SYARAF AUTONOM

Symphatethic division

Parasymphatethic division

SH2 domain

The Reception and Transduction of Signals

b

G protein

a g GDP b g

+ Signal

-GDP

+GTP

a

GDP

a

GTP

a

GTP

Adenylate cyclase

+ Signal

b Activation P

Protein Phosphatase

a

Glycogen Synthase

Glycogen Synthase

P

active

Insulin

P P

P P kinase

Glucagon

A

G-protein-linked Receptor

Enzyme-linked Receptor The third group:

Ion-channel-linked Receptor

The fourth group:

Steroid Receptor

Glycogen breakdown

Glycogen

Non polar Pass through the membrane cell Receptor within the cell (Intracellular receptor) Requires carrier molecule Affect gene expression Affect the quantity of active protein

Nucleus

Hormone-receptor complexes

DETECTION OF LIPID SOLUBLE HORMONE BY INTRACELLULAR RECEPTOR

steroid hormone

DNA binding domain

transcription activating domain

inhibitory protein complex

H2N

Cytoplasm

Receptor protein

Steroid hormone molecules enter the cell

H2N

COOH

COOH

Hormone-binding site

DNA-binding site exposed

Hinge region

RNA polymerase

DNA binding domain of various hormones

Cortisol receptor

Estrogen receptor

Progesterone receptor

Vitamine D receptor

Thyroid hormone receptor

Retinoic acid receptor

Activated adenylat cyclase Extracellular

space

Cytosol

Other proteins Cellular responses ( vary with cell type)

Hormone

G-PROTEIN-LINKED RECEPTOR

G protein Adenylate cyclase cAMP (2nd messenger) PKA Other proteins

Receptor

G protein PLC IP3 - DAG (2nd messenger) PKC Other proteins

Receptor

Hormone Phospholipase C

DAG

IP3

PI

PKA PKC 2ATP 2ADP

DAG

IP3

PIP2

PI PIP2

cAMP

DETECTION OF WATER SOLUBLE HORMONE BY G PROTEIN-LINKED RECEPTOR