The binding of ketamine to plasma proteins: Emphasis on human plasma

Dayton, P. G. ; Stiller, R. L. ; Cook, D. R. ; Perel, J. M.
Springer
Published 1983
ISSN:
1432-1041
Keywords:
ketamine ; binding to plasma proteins ; alpha1-acid glycoprotein ; albumin ; pH change
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Medicine
Notes:
Summary We report for the first time that ketamine (K) is bound as much as 47% to human plasma. It was shown that binding of K to plasma and albumin is dependent on pH; binding is decreased at pH lower than 7.4 and increased at higher pH. This is in concordance with the pKa of K being 7.5; the partition coefficient between an organic phase and buffer was found to be sensitive to small pH changes. Binding of K is also influenced by albumin concentration and the affinity of K for human α1-acid glycoprotein (AAG) is much higher than for human albumin (HSA). The major metabolite nor-K does not appreciably displace K from binding sites on HSA. These findings may explain in part the variability of binding of K observed with different human samples. Human cord plasma exhibits a lower binding of K than adult plasma. This is probably the result of much lower AAG concentration in cord compared to adult plasma; cord and adult plasma albumin levels are known to be only slightly different. Since K has 2 optically active isomers, one of which is more potent than the other, experiments on the binding of racemic and the 2 isomers of K were performed; no differences in binding to AAG were found. We were, however, able to show that tris (butoxyethyl) phosphate (TBEP) can abolish binding of K to AAG. Thus the presence of TBEP would interfere in determining plasma levels and distribution of K. An example would be in the measurement of the partition of K between human red cells and plasma. We determined this ratio in human blood in the absence of TBEP and found it to be similar to that reported for dog red blood cells and plasma.
Type of Medium:
Electronic Resource
URL:
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autor Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
autorsonst Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
book_url http://dx.doi.org/10.1007/BF00607095
datenlieferant nat_lic_papers
hauptsatz hsatz_simple
identnr NLM202439968
issn 1432-1041
journal_name European journal of clinical pharmacology
materialart 1
notes Summary We report for the first time that ketamine (K) is bound as much as 47% to human plasma. It was shown that binding of K to plasma and albumin is dependent on pH; binding is decreased at pH lower than 7.4 and increased at higher pH. This is in concordance with the pKa of K being 7.5; the partition coefficient between an organic phase and buffer was found to be sensitive to small pH changes. Binding of K is also influenced by albumin concentration and the affinity of K for human α1-acid glycoprotein (AAG) is much higher than for human albumin (HSA). The major metabolite nor-K does not appreciably displace K from binding sites on HSA. These findings may explain in part the variability of binding of K observed with different human samples. Human cord plasma exhibits a lower binding of K than adult plasma. This is probably the result of much lower AAG concentration in cord compared to adult plasma; cord and adult plasma albumin levels are known to be only slightly different. Since K has 2 optically active isomers, one of which is more potent than the other, experiments on the binding of racemic and the 2 isomers of K were performed; no differences in binding to AAG were found. We were, however, able to show that tris (butoxyethyl) phosphate (TBEP) can abolish binding of K to AAG. Thus the presence of TBEP would interfere in determining plasma levels and distribution of K. An example would be in the measurement of the partition of K between human red cells and plasma. We determined this ratio in human blood in the absence of TBEP and found it to be similar to that reported for dog red blood cells and plasma.
package_name Springer
publikationsjahr_anzeige 1983
publikationsjahr_facette 1983
publikationsjahr_intervall 8019:1980-1984
publikationsjahr_sort 1983
publisher Springer
reference 24 (1983), S. 825-831
schlagwort ketamine
binding to plasma proteins
alpha1-acid glycoprotein
albumin
pH change
search_space articles
shingle_author_1 Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
shingle_author_2 Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
shingle_author_3 Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
shingle_author_4 Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
shingle_catch_all_1 Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
The binding of ketamine to plasma proteins: Emphasis on human plasma
ketamine
binding to plasma proteins
alpha1-acid glycoprotein
albumin
pH change
ketamine
binding to plasma proteins
alpha1-acid glycoprotein
albumin
pH change
Summary We report for the first time that ketamine (K) is bound as much as 47% to human plasma. It was shown that binding of K to plasma and albumin is dependent on pH; binding is decreased at pH lower than 7.4 and increased at higher pH. This is in concordance with the pKa of K being 7.5; the partition coefficient between an organic phase and buffer was found to be sensitive to small pH changes. Binding of K is also influenced by albumin concentration and the affinity of K for human α1-acid glycoprotein (AAG) is much higher than for human albumin (HSA). The major metabolite nor-K does not appreciably displace K from binding sites on HSA. These findings may explain in part the variability of binding of K observed with different human samples. Human cord plasma exhibits a lower binding of K than adult plasma. This is probably the result of much lower AAG concentration in cord compared to adult plasma; cord and adult plasma albumin levels are known to be only slightly different. Since K has 2 optically active isomers, one of which is more potent than the other, experiments on the binding of racemic and the 2 isomers of K were performed; no differences in binding to AAG were found. We were, however, able to show that tris (butoxyethyl) phosphate (TBEP) can abolish binding of K to AAG. Thus the presence of TBEP would interfere in determining plasma levels and distribution of K. An example would be in the measurement of the partition of K between human red cells and plasma. We determined this ratio in human blood in the absence of TBEP and found it to be similar to that reported for dog red blood cells and plasma.
1432-1041
14321041
Springer
shingle_catch_all_2 Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
The binding of ketamine to plasma proteins: Emphasis on human plasma
ketamine
binding to plasma proteins
alpha1-acid glycoprotein
albumin
pH change
ketamine
binding to plasma proteins
alpha1-acid glycoprotein
albumin
pH change
Summary We report for the first time that ketamine (K) is bound as much as 47% to human plasma. It was shown that binding of K to plasma and albumin is dependent on pH; binding is decreased at pH lower than 7.4 and increased at higher pH. This is in concordance with the pKa of K being 7.5; the partition coefficient between an organic phase and buffer was found to be sensitive to small pH changes. Binding of K is also influenced by albumin concentration and the affinity of K for human α1-acid glycoprotein (AAG) is much higher than for human albumin (HSA). The major metabolite nor-K does not appreciably displace K from binding sites on HSA. These findings may explain in part the variability of binding of K observed with different human samples. Human cord plasma exhibits a lower binding of K than adult plasma. This is probably the result of much lower AAG concentration in cord compared to adult plasma; cord and adult plasma albumin levels are known to be only slightly different. Since K has 2 optically active isomers, one of which is more potent than the other, experiments on the binding of racemic and the 2 isomers of K were performed; no differences in binding to AAG were found. We were, however, able to show that tris (butoxyethyl) phosphate (TBEP) can abolish binding of K to AAG. Thus the presence of TBEP would interfere in determining plasma levels and distribution of K. An example would be in the measurement of the partition of K between human red cells and plasma. We determined this ratio in human blood in the absence of TBEP and found it to be similar to that reported for dog red blood cells and plasma.
1432-1041
14321041
Springer
shingle_catch_all_3 Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
The binding of ketamine to plasma proteins: Emphasis on human plasma
ketamine
binding to plasma proteins
alpha1-acid glycoprotein
albumin
pH change
ketamine
binding to plasma proteins
alpha1-acid glycoprotein
albumin
pH change
Summary We report for the first time that ketamine (K) is bound as much as 47% to human plasma. It was shown that binding of K to plasma and albumin is dependent on pH; binding is decreased at pH lower than 7.4 and increased at higher pH. This is in concordance with the pKa of K being 7.5; the partition coefficient between an organic phase and buffer was found to be sensitive to small pH changes. Binding of K is also influenced by albumin concentration and the affinity of K for human α1-acid glycoprotein (AAG) is much higher than for human albumin (HSA). The major metabolite nor-K does not appreciably displace K from binding sites on HSA. These findings may explain in part the variability of binding of K observed with different human samples. Human cord plasma exhibits a lower binding of K than adult plasma. This is probably the result of much lower AAG concentration in cord compared to adult plasma; cord and adult plasma albumin levels are known to be only slightly different. Since K has 2 optically active isomers, one of which is more potent than the other, experiments on the binding of racemic and the 2 isomers of K were performed; no differences in binding to AAG were found. We were, however, able to show that tris (butoxyethyl) phosphate (TBEP) can abolish binding of K to AAG. Thus the presence of TBEP would interfere in determining plasma levels and distribution of K. An example would be in the measurement of the partition of K between human red cells and plasma. We determined this ratio in human blood in the absence of TBEP and found it to be similar to that reported for dog red blood cells and plasma.
1432-1041
14321041
Springer
shingle_catch_all_4 Dayton, P. G.
Stiller, R. L.
Cook, D. R.
Perel, J. M.
The binding of ketamine to plasma proteins: Emphasis on human plasma
ketamine
binding to plasma proteins
alpha1-acid glycoprotein
albumin
pH change
ketamine
binding to plasma proteins
alpha1-acid glycoprotein
albumin
pH change
Summary We report for the first time that ketamine (K) is bound as much as 47% to human plasma. It was shown that binding of K to plasma and albumin is dependent on pH; binding is decreased at pH lower than 7.4 and increased at higher pH. This is in concordance with the pKa of K being 7.5; the partition coefficient between an organic phase and buffer was found to be sensitive to small pH changes. Binding of K is also influenced by albumin concentration and the affinity of K for human α1-acid glycoprotein (AAG) is much higher than for human albumin (HSA). The major metabolite nor-K does not appreciably displace K from binding sites on HSA. These findings may explain in part the variability of binding of K observed with different human samples. Human cord plasma exhibits a lower binding of K than adult plasma. This is probably the result of much lower AAG concentration in cord compared to adult plasma; cord and adult plasma albumin levels are known to be only slightly different. Since K has 2 optically active isomers, one of which is more potent than the other, experiments on the binding of racemic and the 2 isomers of K were performed; no differences in binding to AAG were found. We were, however, able to show that tris (butoxyethyl) phosphate (TBEP) can abolish binding of K to AAG. Thus the presence of TBEP would interfere in determining plasma levels and distribution of K. An example would be in the measurement of the partition of K between human red cells and plasma. We determined this ratio in human blood in the absence of TBEP and found it to be similar to that reported for dog red blood cells and plasma.
1432-1041
14321041
Springer
shingle_title_1 The binding of ketamine to plasma proteins: Emphasis on human plasma
shingle_title_2 The binding of ketamine to plasma proteins: Emphasis on human plasma
shingle_title_3 The binding of ketamine to plasma proteins: Emphasis on human plasma
shingle_title_4 The binding of ketamine to plasma proteins: Emphasis on human plasma
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source_archive Springer Online Journal Archives 1860-2000
timestamp 2024-05-06T09:38:13.876Z
titel The binding of ketamine to plasma proteins: Emphasis on human plasma
titel_suche The binding of ketamine to plasma proteins: Emphasis on human plasma
topic V
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