Dopamine- an important neurotransmitter in the CNS, regulates various physiological and pathological processes in the body

4. Dopamine (DA)
Tyrosine crosses readily into the
brain through uptake
Tyrosine Hydroxylase
It is abundant in the brain as
well as in the periphery
In Dopaminergic cell the end point of synthesis is Dopamine but at other sites
of NE transmission it is converted to NE by dopamine ß hydroxylase

5. DAT

8. SITE ROLE
Heart and CV System DA is able to activate ß adrenergic receptors to further
increase cardiac contractility
Kidney Renal DA primarily serves to increase natriuresis, though
it can also increase renal blood flow and glomerular
filtration
Pituitary Gland DA is the primary regulator of prolactin secretion from the
pituitary gland.
Catecholamine Release The D2 receptor provides tonic inhibition of epinephrine
release from chromaffin cells of the adrenal medulla, and
of norepinephrine release from sympathetic nerve
terminals.
In contrast, the D1 receptor responds to high-frequency
DA stimulation to promote the release of catecholamines
from the adrenal medulla.
GITract Abundace of Dopamine receptor initate Emesis
CNS

10. The physiological processes under
dopaminergic control include reward,
emotion, cognition, memory, and motor
activity

11. Pathways Activity Dysfunction
The mesolimbic
pathway
Reward and learned
behaviors
schizophrenia, and
psychoses
(including bipolar
depression) and
learning deficits
Mesocortical
pathway
Motivation, reward,
emotion, and
impulse control
Psychoses,
including
schizophrenia, and
in attention-deficit
hyperactivity
disorder
Nigrostriatal
pathway
regulator of
movement
Parkinson disease
Tuberoinfundibular regulates prolactin
secretion.
Hyperprolactinemia

24. Antipsychotic
Typical
Mechanism of action toxicity
Phenothiazines:
-chlorpromazine
-fluphenazine
-thioridazine
Thioxanthenes
Thiothixene
flupenthixol
Blockade of
D2>>5HT2A
Akathisia,Dystonia,
parkinson symptom
,tardive dyskinesia,
hyperprolactinemia
Butyrophenones
Haloperidol
Droperidol
domperidone
Blockade of
D2>>5HT2A
Extrapyrimidal
dysfunction

27. Antipsychotic
Atypical
Mechanism of action toxicity
Aripiprazole
Clozapine
Olanzapine
Quetiapine
Risperidone
Ziprasidone
Blockade of 5HT2A>D2 Agranulocytosis(Clozapine),Weight
gain, low seizure threshold,
cataract, QT prolongation
Atypical Antipsychotics

29. The effects of psychostimulants include
increases in heart rate, body
temperature, and sweating;
improvements in alertness, attention,
and endurance; increases in pleasure
produced by rewarding events; but at
higher doses agitation, anxiety, or
even loss of contact with reality

31. Dose Effect
at low infusion rates (about 2
micrograms/kg per
minute
Dopamine differs from adrenaline and
noradrenaline in dilating renal and
mesenteric blood vessels and increasing
urine output
At slightly higher infusion rates (around 2
to
10 micrograms/kg per minute)
This effect is predominant
it also stimulates beta1-adrenergic
receptors in the myocardium,
Even higher 10 to 20 micrograms/kg per
minute
the effects of alpha adrenergic
stimulation, vasoconstriction
predominate

33. • Metoclopramide & Domperidone
• Butyrophenones(Chlorpromazine and others)