biology

Histidine-tryptophan-ketoglutarate

Histidine-tryptophan-ketoglutarate is a biology 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 Histidine-tryptophan-ketoglutarate rather than just read about it. In short: Histidine-tryptophan-ketoglutarate (HTK) is a high-flow, low-potassium preservation solution used for organ transplantation. The solution was initially developed by Hans-Jürgen Bretschneider.

Key takeaways

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

Reference excerpt

Histidine-tryptophan-ketoglutarate (HTK) is a high-flow, low-potassium preservation solution used for organ transplantation. The solution was initially developed by Hans-Jürgen Bretschneider. Currently, HTK Solution is sold under the SERVATOR H or Custodial trademarks. HTK solution is intended for perfusion and flushing of donor liver, kidney, heart, lung and pancreas prior to removal from the donor and for preserving these organs during hypothermic storage and transport to the recipient. HTK solution is based on the principle of inactivating organ function by withdrawal of extracellular sodium and calcium, together with intensive buffering of the extracellular space by means of histidine/histidine hydrochloride, so as to prolong the period during which the organs will tolerate interruption of oxygenated blood. The composition of HTK is similar to that of intracellular fluid. All of the components of HTK occur naturally in the body. The osmolarity of HTK is 310 mOsm/L.

Composition Sodium: 15 mmol/L Potassium: 9 mmol/L Magnesium: 4 mmol/L Calcium: 0.015 mmol/L Ketoglutarate/glutamic acid: 1 mmol/L Histidine: 198 mmol/L Mannitol: 30 mmol/L Tryptophan: 2 mmol/L

Clinical Application HTK (branded as SERVATOR H by Global Transplant Solutions, Inc.), has been presented by industry to surgeons as an alternative solution that exceeds other cardioplegias in myocardial protection during cardiac surgery. This claim relies on the single-dose administration of HTK compared with other multidose cardioplegias (MDC), sparing time in the adjustment of equipment during cardioplegia re-administration, allowing greater time to operate and thus a decreased CPB duration. Other benefits include a lower concentration of sodium, calcium, and potassium compared with other cardioplegias with cardiac arrest arising from the deprivation of sodium. Finally, histidine is thought to aid buffering, mannitol and tryptophan to improve membrane stability, and ketoglutarate to help ATP production during reperfusion. A 2021 meta-analysis demonstrated no statistical advantage of HTK over blood or other crystalloid cardioplegias during adult cardiac surgery. The only practical advantage of HTK, therefore, is the single-dose administration compared to multi-dose requirements of blood and other crystalloid cardioplegia.

See also Viaspan (UW Solution) Biostasis Organ transplant

References 1. 510(k) Summary. Custodiol HTK Solution Common/Classification Name: Isolated Kidney Perfusion and Transport System and Accessories, 21 CFR 876.5880; Franz Kohler. Prepared December 14, 2004. https://www.fda.gov/cdrh/pdf4/K043461.pdf 2. Ringe B., et al. Safety and efficacy of living donor liver preservation with HTK solution. Transplant Proc. 2005;37:316–319. 3. Agarawal A., et al. Follow-up experience using histidine-tryptophan-ketoglutarate solution in clinical pancreas transplantation Transplant Proc. 2005;37:3523–3526. 4. Pokorny H., et al.: Histidine-tryptophan-ketoglutarate solution for organ preservation in human liver transplantation — a prospective multi-centre observation study. Transpl Int. 2004;17:256-60. 5. de Boer J., et al.: Eurotransplant randomized multicenter kidney graft preservation study comparing HTK with UW and Euro-Collins. Transpl lnt. 1999;12:447-453. 6. Hesse U.J., et al.: Organ preservation with HTK and UW solution. Pabst Sci. Publishers, D-49525 Lengerich, 1999. 7. Hatano E., et al.: Hepatic preservation with histidine-tryptophan-ketoglutarate solution in living related and cadaveric liver transplantation. Clin Sci. 1997;93:81-88.

Specific

External links Official Custodiol Website Custodiol HTK Canadian Website

Worked examples

Example 1 — a first encounter with Histidine-tryptophan-ketoglutarate

Start with the simplest possible case. Write down what Histidine-tryptophan-ketoglutarate claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, 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 Histidine-tryptophan-ketoglutarate 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 Histidine-tryptophan-ketoglutarate 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 Histidine-tryptophan-ketoglutarate

In research: Histidine-tryptophan-ketoglutarate appears in biology 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 Histidine-tryptophan-ketoglutarate 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: Histidine-tryptophan-ketoglutarate is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cryobiology, Transplantation medicine, so understanding it makes those chapters shorter.
In everyday life: Look for Histidine-tryptophan-ketoglutarate 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Histidine-tryptophan-ketoglutarate” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Histidine-tryptophan-ketoglutarate in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Histidine-tryptophan-ketoglutarate 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 Histidine-tryptophan-ketoglutarate out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Histidine-tryptophan-ketoglutarate in simple terms?

Histidine-tryptophan-ketoglutarate (HTK) is a high-flow, low-potassium preservation solution used for organ transplantation. The solution was initially developed by Hans-Jürgen Bretschneider.

Why does Histidine-tryptophan-ketoglutarate matter?

Because it connects several biology 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 Histidine-tryptophan-ketoglutarate?

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 Histidine-tryptophan-ketoglutarate.