Synthesis of Catecholamines: Noradrenaline, Adrenaline, and Dopamine

🧠 Catecholamines are a group of chemicals involved in neurotransmission and are formed by a catechol group and an amine group.

⚡️ The synthesis of catecholamines begins with tyrosine, which is converted into L-DOPA by the enzyme tyrosine hydroxylase.

💪🏽 The conversion of L-DOPA into dopamine, norepinephrine, and epinephrine involves a series of enzymatic reactions.

🧠 Catecholamines, such as noradrenaline, adrenaline, and dopamine, play important roles in the nervous system.

🔬 Dopamine is synthesized from dopa through the action of the enzyme dopa-descarboxilase, while noradrenaline is synthesized from dopamine through the action of the enzyme dopamine beta-hydroxylase.

⚡ In the adrenal medulla, noradrenaline can be further converted into adrenaline through the action of the enzyme phenylethanolamine N-methyltransferase.

🧬 The synthesis of catecholamines involves the conversion of tyrosine to dihydroxyphenylalanine (DOPA), which is then transformed into dopamine.

🔁 Dopamine is transported into vesicles by a vesicular transporter called VMAT, which can transport various monoamines, including noradrenaline, adrenaline, and serotonin.

⚡️ Dopamine is further converted into noradrenaline by the enzyme dopamine beta-hydroxylase, which is found in the vesicles.

🧬 Catecholamines like noradrenaline, adrenaline, and dopamine play a crucial role in the body.

⚡️ The release of noradrenaline and dopamine occurs when calcium enters the neuron terminal.

🎯 Noradrenaline can activate post-synaptic alpha and beta receptors.

🧠 When catecholamines are activated, the neuron that expresses them decreases exocytosis, resulting in a negative regulation of neurotransmitter release.

⬇️ High levels of neurotransmitters in the synaptic cleft bind to presynaptic receptors, leading to a decrease in subsequent neurotransmitter release.

🔄 Approximately 50% of noradrenaline is recaptured by the noradrenaline transporter, contributing to a feedback loop that inhibits neurotransmitter release.

🧠 The video discusses the synthesis of catecholamines, including noradrenaline, adrenaline, and dopamine.

💊 There is a space called the extraneuronal or extrasynaptic space where noradrenaline can be recaptured.

🔬 The enzyme tyrosine hydroxylase plays a crucial role in the synthesis of catecholamines.

🧪 The enzyme tyrosine hydroxylase is crucial for the production of catecholamines.

🚫 Inhibiting tyrosine hydroxylase can be useful in extreme cases of catecholamine overproduction.

💡 The inhibition of dopamine beta-hydroxylase and dopa-decarboxylase does not significantly affect catecholamine production.