Behavioural Pharmacology Flashcards
Pharmacodynamics –
Pharmacokinetics –
what does the drug do to the organism
what does the organism do to the drug
Drug Effect vs Drug Action
Example: Morphine
Pain relief Constipation Miosis (reduce the size of the pupil) Euphoria Addiction
Stimulation of μ-opioid receptors (metabotropic receptors)
Morphine leads to miosis
Carbachol leads to miosis
Stimulation of μ-opioid receptors
Stimulation of musc. acetylcholine receptors
Drug action can occur via two different mechanisms:
A general action (non specific)
A specific interaction with a protein such as a receptor, an enzyme or a transporter molecule
Drug administration:
In order to get a drug to the target organ, we use blood vessels as a means of transportation, and thus the…
intravenous (i.v.) injection is the most rapid method of delivery
Absorption and Distribution Size of the molecule Lipophilicity Electrical charge Specific transport mechanisms
small is good
fat-loving is good - since the membranes of cells contain high levels of lipids (fats), the more lipid soluble a drug is, the better it will diffuse through the lipid bilayer of the cell membrane.
neutral is good
The blood brain barrier
Small gaps in the walls to allow substances (and immune/white blood cells) to move from within the blood vessels, outside.
Specific vesicles contain substances from within the blood vessels and move to other side and open up and release those substances directly into the surrounding tissue.
Brain capillaries/blood vessels do not have pinocytotic vesicles. The intracellular cleft, the opening between the different cells that form the wall of the blood vessel are gone, the junction is really tight.
Astrocytes form an additional barrier around the blood vessel. As a result, really hard for substances in the blood to be released and work inside the brain. This is beneficial as it stops substances from causing harm to the brain. From a pharmacological view, it is difficult to treat patients with certain drugs. Need drugs that can penetrate all these barriers.
After the drug has entered the blood, it can be transported to the target organ, where it can diffuse out of the small blood vessels (capillaries) into the organs.
Pinocytotic vesicles can transfer large materials through the cells.
The brain is surrounded by the BBB which aims to prevent external substances from entering the CNS.
Cells that form the blood vessels are tightly connected, and pinocytotic vesicles are rare. The blood vessels are surrounded by astrocytes, which form an additional barrier around the blood vessel. Very lipophilic substances can easily penetrate membranes, and therefore reach the brain.
Median Eminence:
part of the…
key role in the hormonal control of the pituitary gland, by releasing neurohormones
These neurohormones are…
A weaker BBB would allow these molecules to…
hypothalamus
relatively large molecules
leave the brain and enter into the blood
Choroid plexus:
a structure in the brain ventricles where…
The CSF will remove….
consists of cells that collect waste material and release it in the CSF inside the ventricles. BBB is weaker, in order to allow waste products to get out, to prevent them from accumulating in the brain and causing potential harm.
the cerebrospinal fluid (CSF) is generated.
metabolic waste products from the brain
Pineal Gland: An area where substances have to be released from the brain... Releases the hormone... This hormone is released in the... Plays an important role in... Because it is highly...
into the periphery melatonin dark sleep-wake regulation. hydrophilic, the release from the pineal gland into the blood stream is made possible by a weak BBB
Drug Binding
Drugs can bind to two different types of receptors:
(1) Silent receptors
- Fat, bones, other tissues
- Plasma proteins
(2) Active receptors
Classical Theory of Clark and Gaddum (1920)
The saturation effect:
with increasing concentrations of a drug, the response… Further increasing the dose does not…
The stereoselectivity effect.
drugs can exist in two conformations that are the same in… only one of the two forms has a….
This suggests that the 3D structure of the molecule determines…
increases as well, until, at a certain concentration a maximal response is obtained.
lead to any increase anymore.
chemical composition and sequence of chemical bonds, but they differ in the three dimensional structure.
biological effect.
its effect
Classical Theory of Clark and Gaddum (1920)
The saturation effect:
with increasing concentrations of a drug, the response… Further increasing the dose does not…
The stereoselectivity effect.
drugs can exist in two conformations that are the same in… only one of the two forms has a….
This suggests that the 3D structure of the molecule determines…
The effect of a drug is proportional to the…
The maximal effect occurs when…
increases as well, until, at a certain concentration a maximal response is obtained.
lead to any increase anymore.
chemical composition and sequence of chemical bonds, but they differ in the 3D structure.
biological effect.
its effect
number of receptors occupied
all receptors are occupied.
Area Postrema an area located in the medulla of the brainstem (vomiting region) function? important... trigger a...
protector of the body
vomiting response when activated by toxic substances.
