Ro5-4864: What It Does, How It Works, and Where It’s Used

Ro5-4864, also called 4′-chlorodiazepam, is a chemical researchers use in labs. It attaches to the Translocator Protein (TSPO) found in the mitochondria, which are the energy centers in our cells. This is different from more familiar drugs like diazepam (Valium), which target GABA_A receptors and cause calming effects. Ro5-4864 doesn’t do that, it doesn’t make you sleepy or less anxious. Instead, it’s mainly for studying how TSPO works in making certain hormones, dealing with the immune system, and protecting nerves. If someone uses it without proper supervision, it can actually make anxiety or seizures worse.

• Ro5-4864 comes from diazepam but works on TSPO, not GABA_A.
• It’s not meant for treating people; just for lab tests.
• In animals, it can sometimes cause seizures or anxiety.

Getting to Know Ro5-4864

Ro5-4864 is part of the 1,4-benzodiazepin-2-one family of chemicals. Roche, the pharmaceutical company, created it. The “Ro” comes from their name. There are no approved uses for people, and you won’t find it in regular medical trials.

Unlike diazepam or clonazepam, Ro5-4864 doesn’t bind to GABA_A receptors much at all. A change in where a chlorine atom is placed makes it act differently, focusing on TSPO.

The Chemical Basics

How Ro5-4864 is Built

Ro5-4864 is a white powder with a specific structure, including a chlorine atom that directs it to TSPO. The molecule doesn’t have handedness (achiral).

• Scientific Name: 7-chloro-5-(4-chlorophenyl)-1-methyl-3H-1,4-benzodiazepin-2-one
• Also Known As: 4′-chlorodiazepam
• Chemical Formula: C₁₆H₁₂Cl₂N₂O
• Weight: 319.19 g/mol

Physical Qualities and How to Dissolve It

Ro5-4864 is a solid powder. It doesn’t dissolve well in water but does dissolve in DMSO at concentrations up to 100 mg/mL. For lab use, DMSO should be very pure, over 99.9%.

To prepare it for experiments:

1. Dissolve in DMSO up to 100 mg/mL.
2. Split into small containers and keep at -20°C (good for three months) or in the fridge after opening.
3. Don’t freeze and thaw it repeatedly.
4. Use DMSO-safe nylon filters if filtering is needed.
5. For cell tests, keep DMSO below 0.5% of the total; dilute before use.

Its logP is about 3.8, making it easy to cross cell membranes and reach the mitochondria.

How Ro5-4864 Works

Binding to TSPO, Not GABA_A

TSPO is a protein on the outside of mitochondria. Ro5-4864 binds very strongly to it. It barely affects GABA_A receptors at all.

What Does That Change in the Cell?

TSPO helps move cholesterol into the mitochondria, which is needed to make certain hormones. Ro5-4864 boosts this process, increasing things like pregnenolone and hormones such as testosterone and progesterone. This can affect brain activity, immune function, and how cells survive.

• Steroid Building: Helps make neurosteroids.
• Energy and Cell Health: Changes how much energy cells make and their stability.
• Cell Survival: Sometimes helps cells survive, sometimes makes them die, depending on the dose.

What We See in Cell Studies

Ro5-4864 makes cells change how much energy they produce and can increase mitochondrial activity. It slows down T-cell growth and stops certain immune responses from mast cells. Low amounts can help cells grow, but high amounts can be toxic.

What Happens in Animal Studies?

Brain and Behavior Effects

Ro5-4864 doesn’t calm animals, unlike classic benzodiazepines. It can actually make them more anxious or cause seizures.

• In mice, doses of 1–15 mg/kg increase seizure risk from loud noises.
• In baboons, 1–3 mg/kg given by IV changes how they react to light; 10 mg/kg causes convulsions.

Protection for Nerves and Pain

Examples from research:

For nerve pain, at low doses, Ro5-4864 helps nerves recover and can encourage repair cells to grow.

Body-Wide Effects

In animal models of lung injury:

It can also limit how T-cells react to certain allergens.

Why Scientists Use Ro5-4864

A Common Chemical for TSPO Research

Researchers use Ro5-4864 to understand TSPO’s job, often comparing it to other TSPO ligands like PK11195. It’s used to study brain disorders, pain, immune diseases, and cancer.

For Brain Imaging: [11C]Ro5-4864 and PET

To make [¹¹C]Ro5-4864:

1. Start with a special chemical base.
2. Add the radioactive [¹¹C]CH₃I plus base and solvent in a cooled container.
3. Heat it to attach the radioactive carbon.
4. Clean up with automated machines and a series of washes and filters.

Outcome: The yield is about a third of the starting amount. It helps scan TSPO in inflamed areas or tumors, although it’s not the best choice for every brain tumor.

How Ro5-4864 Compares to Classic Benzodiazepines

Could Ro5-4864 Have Medical Uses One Day?

Right now, TSPO research is mostly about understanding things like hormone production, inflammation, and nerve cell health. Ro5-4864 serves as a test tool, there’s no plan to use it as a medicine itself.

Safety: It can be dangerous if taken; causes anxiety and seizures. There’s no human safety data, just studies in animals and cells. It doesn’t bind as well to human brain tumors as some other chemicals.

Buying and Legal Considerations

Buying advice: If buying for research, suppliers label it “not for human use.” It’s often restricted in the USA and UK. Always check purity, local rules, and make sure you have the right lab setup.

If you’re looking at Buy Ro5-4864, wear protective gear and use it safely.

Lab Safety Tips

Always use gloves, a lab coat, and goggles in a fume hood. Store safely and securely. Keep records. Dispose according to local safety rules.

Ro5-4864: What to Remember

1. What is this? A chemical for studying TSPO, not a tranquilizer.
2. Why do labs care? It helps show how the body makes steroids and responds to injury or inflammation.
3. Any dangers? It can cause anxiety and seizures; for lab use only.

Common Questions

1. Is Ro5-4864 basically the same as Valium?
No. They work differently and do opposite things.

2. Can Ro5-4864 treat anxiety?
No. In fact, it often causes anxiety in animal studies.

3. Is it legal to buy Ro5-4864?
Depends on where you live; for research only, check your local laws.

4. Why is TSPO important?
TSPO helps move cholesterol into the mitochondria to make hormones, produce energy, and fight inflammation.