science

Pentylenetetrazol

Pentylenetetrazol is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Pentylenetetrazol rather than just read about it. In short: Pentylenetetrazol (PTZ), or pentylenetetrazole, also known as pentetrazol (INNTooltip International Nonproprietary Name) and sold under the brand name Metrazol, is a drug formerly used as a circulatory and respiratory stimulant. High doses cause convulsions, as discovered by Hungarian-American neurologist and psychiatrist Ladislas J.

Key takeaways

Pentylenetetrazol belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Pentylenetetrazol to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Pentylenetetrazol from memory before moving on to harder problems.

Reference excerpt

Pentylenetetrazol (PTZ), or pentylenetetrazole, also known as pentetrazol (INNTooltip International Nonproprietary Name) and sold under the brand name Metrazol, is a drug formerly used as a circulatory and respiratory stimulant. High doses cause convulsions, as discovered by Hungarian-American neurologist and psychiatrist Ladislas J. Meduna in 1934. It has been used in convulsive therapy, and was found to be effective in treating depression, but side effects, such as uncontrolled seizures, were difficult to avoid. In 1939, pentylenetetrazol was replaced by electroconvulsive therapy (ECT), which is easier to administer, as the preferred method for inducing seizures in England's mental hospitals. In the US, pentylenetetrazol's approval by the Food and Drug Administration (FDA) was revoked in 1982. It is used in Italy as a cardio-respiratory stimulant in combination with dihydrocodeine in a cough suppressant drug.

Side effects Pentylenetetrazol is anxiogenic and has been known to induce severe anxiety in humans.

Pharmacology

Mechanism of action The mechanism of pentylenetetrazol is not well-understood, and it may have multiple actions. In 1984, Squires et al. published a report analyzing pentylenetetrazol and several structurally related convulsant drugs. They found that in-vivo convulsant potency was strongly correlated to in-vitro affinity to the picrotoxin binding site on the GABAA receptor. Many GABAA receptor ligands, such as diazepam and phenobarbital, are effective anticonvulsants, but pentylenetetrazol presumably has the opposite effect when it binds to the GABAA receptor. Several studies have focused on the way pentylenetetrazol influences neuronal ion channels. A 1987 study found that pentylenetetrazol increases calcium influx and sodium influx, both of which depolarize the neuron. Because these effects were antagonized by calcium channel blockers, pentylenetetrazol apparently acts at calcium channels, and it causes them to lose selectivity and conduct sodium ions, as well.

Research Pentylenetetrazol has been used experimentally to study seizure phenomena and to identify pharmaceuticals that may control seizure susceptibility. Recent preclinical work has used pentylenetetrazol to evaluate experimental antiseizure compounds. For example, the synthetic molecule BICS01 showed no protective effect against PTZ induced seizures in mice despite suppressing epileptiform activity in hippocampal slice models For instance, researchers can induce status epilepticus in animal models. Pentylenetetrazol is also a prototypical anxiogenic drug and has been extensively used in animal models of anxiety. Pentylenetetrazol produces a reliable discriminative stimulus, which is largely mediated by the GABAA receptor. Several classes of compounds can modulate the pentylenetetrazol discriminative stimulus, including 5-HT1A, 5-HT3, NMDA, glycine, and L-type calcium channel ligands. Pentylenetetrazol is being studied as a wakefulness-promoting agent in the treatment of idiopathic hypersomnia and narcolepsy.

See also List of investigational narcolepsy and hypersomnia drugs GABAA receptor negative allosteric modulator GABAA receptor § Ligands

References

Illustrations

Worked examples

Example 1 — a first encounter with Pentylenetetrazol

Start with the simplest possible case. Write down what Pentylenetetrazol claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Pentylenetetrazol before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Pentylenetetrazol ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Pentylenetetrazol

In research: Pentylenetetrazol appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Pentylenetetrazol in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Pentylenetetrazol is common in secondary-school and first-year university syllabi. It links to neighbouring topics Antidepressants, Anxiogenics, Calcium channel openers, so understanding it makes those chapters shorter.
In everyday life: Look for Pentylenetetrazol outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Pentylenetetrazol in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Pentylenetetrazol means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Pentylenetetrazol out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Pentylenetetrazol in simple terms?

Why does Pentylenetetrazol matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Pentylenetetrazol?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Pentylenetetrazol.