Podcast
Questions and Answers
Which of the following best defines autacoids?
Which of the following best defines autacoids?
- Endogenous substances with no biological activity
- Endogenous substances with biological activity (correct)
- Synthetic substances with biological activity
- Exogenous substances with biological activity
What is the main characteristic of autacoids known as 'local hormones'?
What is the main characteristic of autacoids known as 'local hormones'?
- Circulated in blood
- Not released or stored in glands (correct)
- Produce systemic action
- Formed at the site of action
Which chemical classification do histamine and serotonin belong to?
Which chemical classification do histamine and serotonin belong to?
- Steroids
- Vasoactive Peptides
- Amino Acid derivatives (correct)
- Eicosanoids
Which autacoid is known as 5-Hydroxytryptamine or 5-HT?
Which autacoid is known as 5-Hydroxytryptamine or 5-HT?
What is the source of histamine?
What is the source of histamine?
Which autacoid is derived from tryptophan?
Which autacoid is derived from tryptophan?
What is the main characteristic of autacoids known as 'local hormones'?
What is the main characteristic of autacoids known as 'local hormones'?
Which autacoid has very short t1/2?
Which autacoid has very short t1/2?
Which autacoid is classified as an amino acid derivative?
Which autacoid is classified as an amino acid derivative?
What is the characteristic of autacoids as 'locally-acting hormones'?
What is the characteristic of autacoids as 'locally-acting hormones'?
Study Notes
Definitions and Characteristics
- Autacoids are biologically active substances that act as local hormones, influencing physiological functions at their site of synthesis.
- They exhibit properties similar to hormones but primarily function locally rather than systemically.
Local Hormones
- Known as 'local hormones', autacoids operate in close proximity to their site of release, affecting nearby tissues and cells.
- Their action is typically rapid and short-lived, making them integral to local signaling processes.
Chemical Classifications
- Histamine and serotonin belong to the classification of biogenic amines, which are derived from amino acids.
- They play significant roles in various biological processes, including immune response and neurotransmission.
Specific Autacoids
- 5-Hydroxytryptamine, commonly known as 5-HT, is another name for serotonin and is crucial in mood regulation and gastrointestinal function.
- Histamine is primarily sourced from mast cells and basophils, where it is stored and released during allergic reactions and inflammatory responses.
Derivatives and Half-Life
- Serotonin (5-HT) is derived from the amino acid tryptophan, which serves as a precursor in its biosynthesis.
- Autacoids like histamine have a very short half-life (t1/2), indicating rapid degradation and limiting the duration of their effects.
Amino Acid Derivative
- The classification of autacoids such as histamine includes amino acid derivatives, which are important in various physiological and pathological processes.
Locally-Acting Hormones
- Autacoids function as 'locally-acting hormones' by mediating responses to stimuli in a localized area, ensuring swift and targeted action in bodily systems.
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Description
Test your knowledge of autacoids and their pharmacology in this quiz. Challenge yourself to define and classify autacoids, list drugs affecting their synthesis, and identify drugs that block their action.