“Chemotherapy” (what does it mean)  Using a variety of specific chemical compounds to treat illnesses  Chemicals are harmful to pathogenic organisms and can be specific towards them, not attack our cells

Early Attempts to Find Medications  Trial and Error  Long Wait Period between finding the active chemical compound and a medication becoming available for use.

General Mechanism of Drug Action  Attach to a cell receptor and prevent it from binding to its normal substrate.  How?  1) Take up receptor site so no other sites are available  2) Change the receptor’s shape so physical structure is different  **Alterations of chemical structure of receptor and chemical compounds

Examples: PenicillinExamples: Penicillin  First antibiotic  1928—Alexander Fleming  Chain and Florey—purification of penicillin  Group of chemical compounds—all similar structures but different “R” groups.

Penicillin StructurePenicillin Structure Penicillin Amoxicillan

How does penicillin work?How does penicillin work?  Enzyme inhibitor  Bacteria contain cell walls and have an enzyme that participates with cell wall synthesis.

Components of the Nervous System  Neurons— nerve cells  location and features dependent on function  3 parts: dendrites, axons, cell body  Myelin sheath— white color, layer of insulation covering nerve cells.  Types:  Motor/efferent— transmit info from CNS to muscles  Sensory/afferent— transmit info from sensory receptors to CNS  Interneurons— located only in CNS

Nerve TransmissionNerve Transmission  Nerve cells MUST have a way of passing information to each other when responding to a stimuli---what is a stimuli?  Membrane potential  Electric charge difference across a membrane  Resting potential  -70mV  Cell is not transmitting a nerve impulse, “resting”  Negative charge inside cell, dependent on ion distribution across membrane (Na + /K + )

Nerve TransmissionNerve Transmission  Action potential  Polarity (charge) change across a membrane in response to a nerve impulse/signal  ALL or NONE !!!

Action Potentials (cont.)Action Potentials (cont.)  Action potentials JUMP from one neuron to another  Axon of nerve cell ends close to dendrites of another neuron  Area called synapse  To get nerve stimuli past this point, neurotransmitters needed  Molecules released by one neuron and travel to receptors on the other neuron to create response  Ex. Endorphins, dopamine, serotonin

Neurotransmitters  Special chemical compounds synthesized within nerve cells  Usually amine compounds  Bind to receptor sites on neighboring nerve cells and cause a chain of chemical reaction to respond.  Each neurotransmitter has a specific function.

Drugs involved with chemicals functioning as neurotransmitters  Some imitate neurotransmitter  Others can impair neurotransmitter function

Example 1: EpinephrineExample 1: Epinephrine  Also known as “adrenaline”  Made in adrenal glands (on top of your kidneys)  “Fight/flight” response

Example 2: SerotoninExample 2: Serotonin  Regulates sleep, body temperature, etc.  Certain drugs (serotonin antagonists) prohibit this chemical neurotransmitter.

Example 3: Norepinephrine (NE)  Neurotransmitter synthesized in brain  High levels---hyperactive, manic  Low levels—depression possible

Beta-Blocker DrugsBeta-Blocker Drugs  Prevent function of epinephrine and NE  Used to treat hypertension and cardiac arrhythmias

NSAID DrugsNSAID Drugs  “Non-steroidal anti-inflammatory” drug  HUGE group of chemical compounds that work on a specific group of compounds in your body— prostaglandins  Prostaglandins— compounds responsible for inflammation/pain Ibuprofen

How do NSAID Drugs work?  Inhibit the synthesize of prostaglandins  NSAIDS prevent the function of an enzyme necessary to produce them, stops reaction.  What are some of these chemical compounds? What role do they play in chronic pain?

Homework  Read pp  Study for quiz—look over how to name organic compounds and draw structures again.