Bsc class creatine
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The document discusses the importance of creatine and its relationship with creatinine in muscle metabolism and energy storage. It explains the biosynthesis and degradation pathways of creatine, the clinical significance of creatinine as an indicator of kidney function, and the role of creatine kinase in energy production during muscle contraction. Additionally, it covers the dietary sources, dietary supplementation, and implications of creatine and creatinine levels in health and disease.
![What is the purpose of assaying for CK over
a period of time?
Isozymes creatine kinase are tissue specific CK is a
dimer of MM, MB, BB isozymes, and only MB is present in
the myocardium (15% TOTAL CK)
MB-CK: myocardial specific injury
- 100% increase in MB-CK within 4 hr
- Peaks at 8-24 hr then decreases, with aminotranserase
change much slower peak ~ 60 hrs , LDH is the best
indicator to follow the MI from third day(To maximize
treatment, prompt recognition essential)
- Usually [CK] cardium & % MB/total CK are constant,
[MB-CK↑] is proportional to degree injury to myo cardium](https://image.slidesharecdn.com/bscclasscreatine-161128133435/85/Bsc-class-creatine-36-320.jpg)
Bsc class creatine
- 1. By BASALINGAPPA B G MSC MEDICAL BIOCHEMISTRY DEPT OF BIOCHEMISTRY JSS MEDICAL COLLEGE
- 2. 1. To study the importance of creatine in muscle as a storage form of energy 2. To understand the biosynthesis of creatine 3. To study the process of creatine degradation and formation of creatinine as an end product 4. To understand the clinical importance of creatinine as a sensitive indicator of kidney function 5. To study different types of creatine kinase (CK) and their clinical importance Objectives
- 3. What’s Creatine and Creatinine • Creatine and creatinine are not the same substance! • Creatine is found in the muscles……. • Creatinine is a break-down product (a waste product) of creatine phosphate. creatine in muscles, and is usually produced at a fairly constant rate by the body depending on muscle mass.
- 4. 1. The creatine is an amino acid that does not found in proteins. 2. Creatine is a nitrogenous organic acid
- 5. Creatine is a naturally occurring amino acid found in the body (primarily muscle tissue) The daily requirement of creatine is about 2-3 grams/day About half of the daily needs are obtained from the diet (primarily meat and fish) The remaining daily need for creatine is synthesized from the amino acids glycine, arginine, and methionine primarily in the liver Where is Creatine Found?
- 6. Distribution of body creatine From liver, transported to other tissues 98% are present in skeletal and heart muscles In Muscle, gets converted to the high energy source creatine phosphate (phosphocreatine) Creatine Creatine phosphate ATP ADP + H+ ATP ADP Creatine Kinase
- 7. Three amino acids are required: Glycine Arginine Methionine (as S-adenosylmethionine) Site of biosynthesis: Step 1: Kidneys Step 2: Liver Creatine Biosynthesis
- 8. METABOLISM OF CREATINE Two closely related nitrogenous compounds which are connected with protein metabolism are: • Creatine and • Creatinine. Structure and relationship of these two compounds are shown in the box: Characteristics of the reaction • Reaction is irreversible • It is non-enzymatic • Creatinine has ring structure.
- 10. A. First step (Guanidoacetic acid): In the first reaction the amidino group of arginine is transferred to glycine to form guanidoacetic acid, catalyzed by amido transferase . It is seen in mitochondria of kidney and pancreas, but not in liver.
- 11. B. Second step (Creatine): Guanido acetic acid is methylated by S-adenosyl methionine (SAM) by methyl transferase to form creatine. This methylation reaction takes place in liver. S-adenosyl methionine (Active methionine) is the “methyl” donor, for methylation. ATP is required for the synthesis which donates the PO4.
- 12. Also O2 is required for the reaction (aerobic). Reaction is irreversible, and also it occurs in liver. Once creatine-(P) is formed in liver, it goes to muscles, and stored. Creatinine is formed from creatine-(P) in muscles by non-enzymatic and irreversible reaction.
- 13. Third step (Creatine phosphate): Creatine is phosphorylated to creatine phosphate by catalyzed The enzyme creatine kinase (CK) is present in muscle, brain and liver. The reaction needs hydrolysis of ATP. The stored creatine phosphate in the muscle serves as an immediate store of energy in the muscle. During muscle contraction, the energy is first derived from ATP hydrolysis. Thereafter, the ATP is regenerated by the hydrolysis of creatine phosphate . This is called the Lohmann’s reaction .
- 14. Fourth step (Creatinine): The creatine phosphate may be converted to its anhydride, creatinine . It is a non-enzymatic spontaneous reaction. Creatinine is excreted in urine. The blood level of creatine and creatinine, and urinary excretion of creatinine are more or less constant, as long as the muscle mass is not affected.
- 15. Regulation of Creatine Synthesis Dietary creatine has effect on creatine synthesis. In rats, fed a complete diet containing 3 per cent creatine, transamidinase activity of the kidney was markedly lower as compared to control animals. But dietary creatine or a high blood creatine has no effect on rate of synthesis of creatine in liver. It is also shown that hepatic synthesis of creatine is related to the blood glycocyamine levels and that this compound is produced in kidney, suggests that the rate of creatine biosynthesis is actually dependent on kidney transamidinase activity
- 16. What’s the Relationship between Creatine and Creatinephosphate? Creatine and creatine phosphate exist in a reversible equilibrium in skeletal muscle. In skeletal muscle, approximately one-fourth of creatine exists as free creatine and threefourth exists as creatine phosphate.
- 17. Creatine Phosphate Is a high-energy phosphate compound Acts as a storage form of energy in the muscle Provides a small but, ready source of energy during first few minutes of intense muscular contraction The amount of creatine phosphate in the body is proportional to the muscle mass
- 18. 1. Creatine and creatine phosphate spontaneously form creatinine as an end product 2. Creatinine is excreted in the urine 3. Serum creatinine is a sensitive indicator of kidney disease (Kidney function test) 4. Serum creatinine increases with the impairment of kidney function Creatine Degradation
- 19. Creatine Degradation Creatine Creatine phosphate ATP ADP + H+ ATP ADP Creatine Kinase Creatinine H2O Pi Plasma Glomerular filtrationUrine
- 20. Role of Creatine in Muscles Creatine is the reservoir of energy in muscles. When muscles contract, energy is derived from breakdown of ATP to ADP and Pi. ATP must be reformed quickly, to supply the energy, which initially comes from creatine ~ (P), subsequently from glycolysis (contracting muscle).
- 21. From the above reaction, ATP is formed from creatine~ (P). The high energy phosphate is transferred to ADP and ATP is formed. This reaction is called Löhmann reaction and it takes place during activity of the muscles. In the resting condition, creatine ~ (P) is reformed, the enzyme that catalyses the reaction is ATP-creatine transphosphorylase
- 22. A further source of ATP in muscle is by the Myokinase reaction. Two ADP molecules react to produce one molecule of ATP and AMP, the reaction is catalysed by the enzyme myokinase (Adenylate kinase). In this reaction, one high energy phosphate is transferred from one ADP to another ADP molecule to form one ATP.
- 23. Creatine: It is a normal constituent of the body. It is present in muscle, brain, liver, and in blood. Can occur in free form and also as phosphorylated form. The phosphorylated form is called as creatine-PO4 or phosphocreatine or Phosphagen. Total amount in adult human body is approximately 120gm. 98 per cent of total amount is present in muscles, 80 per cent occurs in phosphorylated form, 1.3 per cent in nervous system (brain) and 0.5 to 0.7 per cent in tissues
- 24. Urinary excretion: Urinary excretion in normal health is in the form of creatinine and it is only 2 per cent of the total. In males, it is 1.5 to 2.0 gm in 24 hrs urine, and in females, varies from 0.8 to 1.5 gm. Only vertebrate muscles contain creatine. Creatine concentration is higher in striated muscle as compared to smooth muscle and also in rapidly contracting muscle as compared to pale muscles. Total is 300 to 500 mg/100 gm.
- 25. In invertebrates: Arginine replaces creatine in muscles. Blood and plasma level In whole blood: Creatine level varies from 2 to 7 mg %. In plasma: It is less than 1 mg%. In male: It varies from 0.2 to 0.6 mg%. In females: 0.35 to 0.9 mg%.
- 26. Creatinine: Creatinine is the anhydride of creatine, and it is in this form that creatine is excreted in normal health. Removal of one molecule of H2O is non-enzymatic and irreversible. Total creatinine in muscle is only 0.01 per cent (10 mg).
- 27. Whole blood Muscles • Creatine 2.0 to 7.0 mg% 300 to 500 mg • Creatinine 1.0 to 2.0mg% 0.01% (10 mg) Urinary excretion Creatinine males: 1.5 to 2.0 gm in 24 hr females: 0.8 to 1.5 gm in 24 hr
- 28. Creatinuria Excretion of creatine in urine is called Creatinuria. Creatine excretion occurs: In children: Reason probably lack of ability to convert creatine to creatinine. In adult females in pregnancy and maximum after parturition (2 to 3 weeks). In febrile conditions •In thyrotoxicosis, probably due to associated myopathies
- 29. In muscular dystrophies, myositis, myasthenia gravis. Lack of carbohydrate in diets and in diabetes mellitus. In wasting diseases, e.g. in malignancies. In starvation
- 30. Forms of Creatine Supplements Creatine Monohydrate – Most Common Creatine Phosphate Creatine Citrate Creatine blended w/CHO, Proteins, AA, Caffeine Powders Tablets Gel Liquid
- 31. Documented Side Effects Potential side effects are minor Gastrointestinal (GI) distress No renal or liver dysfunction No cramping in controlled studies Increased Body Mass (water retention in muscle cell due to osmotic changes) Urinary Volume decrease during loading
- 32. Function of Creatine The body only has limited stores of ATP & ADP When a Cr supplement is ingested, & enters the intestines, a majority of Cr is absorbed into the bloodstream. Cr from bloodstream is taken up by skeletal and cardiac muscle through insulin-mediated active transport
- 33. After absorption, a portion of Cr combines with phosphate to form PCr This storage of Cr and PCr allows rapid resynthesis of ATP to meet energy demands via the creatine kinase (CK) reaction Theoretically, Cr supplementation will increase Cr and PCr stores, providing more PCr to be utilized in CK reactions
- 34. Creatine Kinase (CK) CK is responsible for the generation of energy in contractile muscular tissues CK levels are changed in disorders of cardiac and skeletal muscle Creatine Creatine phosphate ATP ADP + H+ ATP ADP Creatine Kinase
- 35. 1. CK is required for conversion of creatine into creatine phosphate 2. CK has 3 isoenzymes: CK-MM mainly in skeletal muscle CK-MB mainly in heart muscle CK-BB mainly in brain 3. Serum total CK is increased in: Crush injuries (Damage of skeletal muscles) Myocardial infarction (Damage of heart muscle) Creatine Kinase (CK)
- 36. What is the purpose of assaying for CK over a period of time? Isozymes creatine kinase are tissue specific CK is a dimer of MM, MB, BB isozymes, and only MB is present in the myocardium (15% TOTAL CK) MB-CK: myocardial specific injury - 100% increase in MB-CK within 4 hr - Peaks at 8-24 hr then decreases, with aminotranserase change much slower peak ~ 60 hrs , LDH is the best indicator to follow the MI from third day(To maximize treatment, prompt recognition essential) - Usually [CK] cardium & % MB/total CK are constant, [MB-CK↑] is proportional to degree injury to myo cardium
- 37. What is the relation of CK activity in the blood to tissue damage? . Diagnostic Value: CK is present in all tissues but only SELECTIVE RELEASE (brain, muscle, but not liver) therefore different from liver damage caused by: Myocardial infarction muscle trauma, muscle dystrophy, severe exertion, IM injections, hypothyroidism, chronic alcoholism (with myopathy
- 38. IS Creatine as an Antioxidant? The mitochondrial isoform of creatine kinase decreases superoxide production by limiting the magnitude of the mitochondrial membrane potential. Meyer et al. J Biol Chem 281: 37361-71, 2006 This is also evident in livers from transgenic mice in which the mitochondrial creatine kinase has been introduced. Hatano et al. Hepatology 24: 663-9, 1996.
- 39. Conclusions Dietary creatine is found in muscle meats and dairy products; however de novo synthesis is responsible for the provision of the greater part of our creatine. The importance of creatine synthesis has recently been underscored by the discovery of the creatine deficiency syndromes. Creatine synthesis makes quite large metabolic demands on amino acid metabolism, particularly that of glycine, arginine and methionine
- 40. References Text book of biochemistry – M N Chatterjia 8th editn Text book of biochemistry - Lehninger Text book of biochemistry - D M Vasudevan 8th editn Text book of biochemistry- A R Aroora 2nd edition Text book of biochemistry – Pankaja Naik 4th edition
- 43. What is the Fate of Creatinine that was Produced from Break Down of Creatine Phosphate during Anaerobic Exercise..? CREATININE EXCRETION The creatinine is a waste product of creatine phosphate and it will be excreted by the kidney in the urine at a rate of 1 to 2 g/day. When creatinine is ingested, most of it is rapidly eliminated in urine. It can be quantitatively recovered. But when creatine is taken, some is retained in the body. It has been seen by giving labelled creatine that 20 to 30 per cent is excreted as creatinine and some is retained in the body whose fate is not known.
- 44. Urine of normal healthy adult male contains creatinine but no creatine. Amount of creatinine excreted as discussed above is approximately 1.0 to 1.5 gm/day and this is: Independant of amount of proteins taken in the diet. Excretion is greater in muscular persons and appears to be related to muscular development and muscular activity. After severe exercise, it may increase, but total amount remains constant from day-to-day.
- 45. Estimation of Creatinine Jaffe’s reaction: Serum is treated with alkaline picrate solution when a red colour develops (Jaffe’s reaction). The colour is read against a ‘standard’ similarly treated in a colorimeter. Estimation of Creatine When heated with acid solution, creatine is converted to creatinine, which can be measured in a similar way as stated above. Value after boiling with acid solution –value before boiling = creatine content. 1.0 gm of creatinine is formed from 1.16 gm of creatine. Hence, substract the pre-formed creatinine from the total creatinine × multiply by 1.16.
- 46. “True” Creatinine Serum creatinine estimation by Jaffe’s reaction does not give “true” creatinine. It measures also certain noncreatinine chromogens, upto 20 per cent in blood and up to 5 per cent in urine. For excluding the chromogens and to get ‘true’ creatinine, after precipitating the proteins,creatinine is adsorbed on to Lloyd’s reagent (Fuller’s earth), a hydrated aluminium silicate, and then colour developed with alkaline picrate.
- 47. Urinary Creatinine A typical male excretes about 15 mmol of creatinine per day A decrease in muscle mass due to muscular dystrophy or paralysis leads to decreased level of creatinine in urine The amount of creatinine in urine is used as an indicator for the proper collection of 24 hours urine sample
- 48. Creatinine Co-efficient It is the ratio of mg of creatinine in urine in 24hours Body wt. in kg The value is 20 to 26 for males 14 to 22 in females. Significance It depends on muscular development and remains fairly constant. As the rate is so constant in a given individual the creatinine co-efficient may serve as a reliable index of the adequacy of a 24-hr urine collection.
- 49. Creatinine Clearance Endogenous creatinine clearance is used as renal function test. At normal levels of creatinine in the blood, this metabolite is filtered at the glomerulus but neither secreted nor re-absorbed by the tubules. Hence its clearance measures the glomerular filtrate rate (GFR) (Refer Chapter on Renal Function Tests)
- 51. The Diagnostic Function of Creatinine
- 52. How is Creatinine Used to Monitor Renal Function…?
- 53. Levels of Creatinine in the Blood Depends Mainly on Renal Function….but… Is there other factors may affect creatinine level in the blood…?
- 54. Serum Creatinine may be Affected Partly by…. The amount of muscle tissue you have. Men tend to have higher levels of blood creatinine because they have more skeletal muscle tissues than women. Protein in diet . Vegetarians have been shown to have lower creatinine levels in blood.
- 55. CLINICAL SIGNIFICANCE OF CREATININE The amount of creatinine excreted from the bodyThe amount of creatinine excreted from the body is proportional to the total creatine phosphateis proportional to the total creatine phosphate content of the body, and thuscontent of the body, and thus can be used tocan be used to estimate muscle mass.estimate muscle mass. Serum creatinine is a sensitive indicator of kidneySerum creatinine is a sensitive indicator of kidney disease (Renal function test)disease (Renal function test) Serum creatinine increases with the impairmentSerum creatinine increases with the impairment of kidney functionof kidney function
- 57. Factors reducing serum creatinine: Low muscle mass Malnutrition Factors increasing serum creatinine : Old age Renal diseases Glomerulonephritis Pyelonephritis Renal failure Urinary obstruction Congestive cardiac failure
- 58. URINE CREATININE The normal daily excretion of creatinine ranges from 1-2 gm. A decrease in muscle mass due to muscular dystrophy or paralysis leads to decreased level of creatinine in urine Creatinine clearance test is widely used as a measure of the glomerular filtration rate and is decreased in renal failure
- 59. Let’s all sing from the same hymn book Creatine….cellular molecule, obtained in the diet or produced endogenously. Creatine-phosphate (phosphocreatine) ”High energy”cellular molecule. Creatine Kinase…an enzyme that reversibly phosphorylates creatine to creatine phosphate. Creatinine…formed as a result of the spontaneous breakdown of creatine and creatine-phosphate. Excreted in the urine. Urinary excretion of creatinine often used to normalize the excretion of other substances. Plasma levels related to renal function