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Anesthesiology Feb 1989Protamine given to neutralize heparin after extracorporeal circulation can trigger a catastrophic reaction in some patients. While searching for a biochemical basis for...
Protamine given to neutralize heparin after extracorporeal circulation can trigger a catastrophic reaction in some patients. While searching for a biochemical basis for this reaction, protamine was tested as an inhibitor of human plasma carboxypeptidase N (CPN) or kininase I, the inactivator of anaphylatoxins and kinins. Human plasma and CPN purified from human plasma, (Mr = 280 K) or its isolated active subunit (Mr = 48 K) were the sources of enzyme. The hydrolysis of furylacryloyl (FA)-Ala-Lys was measured in a UV spectrophotometer and that of bradykinin and the synthetic C-terminal octapeptide of anaphylatoxin C3a (C3a8) by high performance liquid chromatography. Protamine inhibited the hydrolysis of FA-Ala-Lys by CPN, (IC50 = 3.2 X 10(-7) M); added human serum albumin (30 mg/ml) increased the IC50 to 7 X 10(-6) M. When plasma was the source of CPN, the IC50 was 2 X 10(-6) M. Protamine more effectively inhibited the hydrolysis of bradykinin and C3a8. The IC50 for protamine was 5 X 10(-8) M with CPN and bradykinin, 7 X 10(-8) M with CPN and C3a8 and with the 48 K subunit and bradykinin it was 7 X 10(-8) M of protamine. Heparin competes with CPN for protamine, because in high concentration (18 U/ml) it reverses the inhibition by protamine. Protamine did not inhibit angiotensin I converting enzyme (kininase II) or the endopeptidase 24.11 (enkephalinase). Kinetic studies showed the mechanism of protamine inhibition to be partially competitive; about 10-20% of the hydrolysis of bradykinin by CPN was not inhibited by protamine. Thus, by blocking the inactivation of mediators released in shock, protamine inhibition of CPN may be partially responsible for the catastrophic reaction observed to occur in some patients.
Topics: Anaphylatoxins; Carboxypeptidases; Heparin; Humans; In Vitro Techniques; Kinins; Lysine Carboxypeptidase; Peptides; Protamines
PubMed: 2913861
DOI: 10.1097/00000542-198902000-00015 -
Journal of Translational Medicine Feb 2015Unfractionated heparin (UFH) is widely used as a reversible anti-coagulant in cardiopulmonary bypass (CPB). However, the pharmacokinetic characteristics of UFH in CPB... (Observational Study)
Observational Study
BACKGROUND
Unfractionated heparin (UFH) is widely used as a reversible anti-coagulant in cardiopulmonary bypass (CPB). However, the pharmacokinetic characteristics of UFH in CPB surgeries remain unknown because of the lack of means to directly determine plasma UFH concentrations. The aim of this study was to establish a pharmacokinetic model to predict plasma UFH concentrations at the end of CPB for optimal neutralization with protamine sulfate.
METHODS
Forty-one patients undergoing CPB during cardiac surgery were enrolled in this observational clinical study of UFH pharmacokinetics. Patients received intravenous injections of UFH, and plasma anti-FIIa activity was measured with commercial anti-FIIa assay kits. A population pharmacokinetic model was established by using nonlinear mixed-effects modeling (NONMEM) software and validated by visual predictive check and Bootstrap analyses. Estimated parameters in the final model were used to simulate additional protamine administration after cardiac surgery in order to eliminate heparin rebound. Plans for postoperative protamine intravenous injections and infusions were quantitatively compared and evaluated during the simulation.
RESULTS
A two-compartment pharmacokinetic model with first-order elimination provided the best fit. Subsequent simulation of postoperative protamine administration suggested that a lower-dose protamine infusion over 24 h may provide better elimination and prevent heparin rebound than bolus injection and other infusion regimens that have higher infusion rates and shorter duration.
CONCLUSION
A two-compartment model accurately reflects the pharmacokinetics of UFH in Chinese patients during CPB and can be used to explain postoperative heparin rebound after protamine neutralization. Simulations suggest a 24-h protamine infusion is more effective for heparin rebound prevention than a 6-h protamine infusion.
Topics: Adolescent; Adult; Aged; Cardiac Surgical Procedures; Cardiopulmonary Bypass; Computer Simulation; Female; Heparin; Humans; Male; Middle Aged; Models, Biological; Protamines; Young Adult
PubMed: 25638272
DOI: 10.1186/s12967-015-0404-5 -
British Journal of Haematology Mar 2018Heparin anticoagulation followed by protamine reversal is commonly used in cardiopulmonary bypass (CPB). As an alternative to protamine, a recombinant inactive...
Heparin anticoagulation followed by protamine reversal is commonly used in cardiopulmonary bypass (CPB). As an alternative to protamine, a recombinant inactive antithrombin (riAT) was designed as an antidote to heparin and was previously shown to be as potent as protamine in-vitro. In the present study, riAT was assessed for its ability to neutralize heparin after CPB in a rat model. After 60 min of CPB under heparin, rats received 5 mg/kg protamine, 37.5 mg/kg riAT or phosphate buffered saline (PBS) as placebo. Residual anticoagulant activity was assessed using the activated partial thromboplastin time assay before, and 10-30 min after reversion. Haemodynamic monitoring was performed and plasma histamine concentration was also measured. In this model, riAT appeared to be as efficient as protamine in neutralizing heparin. Ten minutes after injection, riAT and protamine both decreased heparin activity, to 1.8 ± 1.3 and 4.5 ± 1.4 u/ml, respectively (23.1 ± 5.1 u/ml in placebo group). Furthermore, evolution of mean carotid arterial pressure, heart rate and plasma histamine levels was comparable in rats treated with PBS or riAT, while protamine exhibited haemodynamic side effects and increased histamine plasma concentration. Thus, riAT could represent an advantage over protamine in CPB because it efficiently reverses heparin activity without negative effects on haemodynamic parameters and plasma histamine level.
Topics: Animals; Anticoagulants; Antithrombins; Cardiopulmonary Bypass; Hemodynamics; Heparin; Heparin Antagonists; Histamine; Male; Protamines; Rats, Wistar
PubMed: 29363751
DOI: 10.1111/bjh.15091 -
Anesthesiology Aug 1991Heparin, currently used in extracorporeal blood circulation procedures, may lead to hemorrhagic complications. Protamine, used for reversal of heparin-induced...
Heparin, currently used in extracorporeal blood circulation procedures, may lead to hemorrhagic complications. Protamine, used for reversal of heparin-induced anticoagulation at the end of such procedures, can cause adverse hemodynamic responses. To prevent both types of complications, we have developed a reactor device containing immobilized protamine (i.e., a protamine bio-reactor) that can be placed at the distal end of the circuit, thus providing simultaneous extracorporeal heparin removal and protamine treatment. In preliminary in vivo studies involving dogs at a blood flow of 100 ml/min, the bio-reactor removed about 50% of the administered dose of heparin (i.e., 100 units/kg) in 10 min. While rapid injection of protamine in dogs anticoagulated with heparin produced a transient and significant (P less than 0.005) decreases in systemic arterial blood pressure (-39.5 +/- 9.2 mmHg), cardiac output (-1.59 +/- 0.23 L/min), and mixed venous oxygen saturation (-7.5 +/- 1.3%) and increases in pulmonary artery systolic (+12.7 +/- 4.4 mmHg) and diastolic pressures (+10.0 +/- 3.6 mmHg), the use of the protamine bio-reactor did not elicit any statistically significant change in any of the variables measured. Hemolysis was not significant, as reflected by a statistically insignificant change of the animals' red blood cell counts, hematocrits, and total hemoglobin values. In addition, hemolytic complement was found to be reduced only by 10% in animals with the protamine bio-reactor, whereas it was reduced rapidly by 20% in animals receiving intravenous protamine administration and progressively by 20% in control animals with a sham reactor that contained no protamine. Furthermore, the use of the protamine bio-reactor also significantly reduced the protamine-induced transient thrombocytopenic and granulocytopenic responses. The white blood cell counts and platelet counts decreased to 87.7 +/- 7.5 and 83.3 +/- 5.0% of baseline, respectively, in dogs with the protamine bio-reactor compared to 35.5 +/- 14.3 and 32.1 +/- 8.1% of baseline in dogs receiving intravenous protamine. The protamine bio-reactor may provide a unique means to simultaneously control both heparin- and protamine-induced complications.
Topics: Animals; Blood Coagulation; Dogs; Extracorporeal Circulation; Female; Hemodynamics; Hemolysis; Heparin; Protamines
PubMed: 1859016
DOI: 10.1097/00000542-199108000-00017 -
The Journal of Surgical Research Jul 1991Protamine reversal of heparin anticoagulation is associated with adverse hemodynamic effects that may be attenuated with protamine pretreatment (PP). This study assesses... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
Protamine reversal of heparin anticoagulation is associated with adverse hemodynamic effects that may be attenuated with protamine pretreatment (PP). This study assesses the role of complement activation during these phenomena in adult cardiac surgery patients. Sixteen individuals undergoing cardiopulmonary bypass were given intravenous normal saline or protamine (2 mg/kg) as a randomized pretreatment prior to undergoing heparin anticoagulation (400 IU/kg), coronary artery revascularization, and subsequent reversal of the anticoagulated state with protamine (4 mg/kg). Blood pressure, pulmonary artery diastolic pressure (PAD), heart rate, and cardiac output (CO) were measured during and after pretreatment, prior to heparin reversal by protamine, and for 10 min after reversal. Total hemolytic complement (CH50), C3 conversion to C3b, C3a/C5a, platelet count, and white blood cell count (WBC) were also measured at the same time periods. No significant correlation existed between complement activation and hemodynamic events, as might have been evident by decreased CH50, increased C3 conversion to C3b, or elevations in C3a/C5a levels. PP significantly prevented the CO decrease occurring at 1 and 3 min following heparin reversal by protamine (-0.8 and -1.4 liters/min vs 0.1 and -0.2 liters/min, P less than 0.05 and P less than 0.01, respectively). Reversal hypotension was less with PP, although PAD fell equally in both groups. WBC decreases after heparin reversal were less after PP (-25% vs -7%, P = 0.06). These data support the conclusion that, contrary to earlier reports, adverse hemodynamic and hematologic responses accompanying protamine reversal of heparin anticoagulation do not appear to be correlated with activation of complement. In fact, those patients having the greatest C3a generation exhibited the least hemodynamic changes.
Topics: Adult; Aged; Anticoagulants; Cardiac Output; Cardiopulmonary Bypass; Complement Activation; Complement C3; Complement C3b; Complement System Proteins; Hemodynamics; Heparin Antagonists; Humans; Male; Middle Aged; Protamines
PubMed: 2067362
DOI: 10.1016/0022-4804(91)90072-t -
Journal of the American College of... Mar 1995This project tested two fundamental hypotheses: 1) Protamine sulfate has a direct and negative effect on myocyte contractile processes; 2) the negative effects of...
OBJECTIVES
This project tested two fundamental hypotheses: 1) Protamine sulfate has a direct and negative effect on myocyte contractile processes; 2) the negative effects of protamine on myocyte contractility will be enhanced in the setting of chronic left ventricular dysfunction.
BACKGROUND
An increasing number of patients undergoing cardiac and vascular surgical procedures have underlying chronic left ventricular dysfunction. Protamine sulfate is commonly required during these surgical procedures but has been associated with left ventricular dysfunction. However, it is not known whether protamine may have a direct and selective effect on myocyte contractility in the setting of chronic left ventricular dysfunction.
METHODS
This study examined the direct effects of protamine on isolated myocyte contractile function in 10 control pigs and 10 pigs with dilated cardiomyopathy induced by supraventricular tachycardia (rapid atrial pacing at 240 beats/min for 3 weeks). Myocyte contractile function was measured by videomicroscopy at baseline and with 10, 20, 40 or 80 micrograms/ml of protamine. In a second series of experiments, myocytes were preincubated with protamine and then stimulated with the beta-adrenergic agonist isoproterenol (25 nmol/liter).
RESULTS
In the presence of 20 micrograms/ml of protamine, myocyte contractile function was unaffected in the control group but decreased by 40% from baseline values in the supraventricular tachycardia group. With 10 micrograms/ml of protamine, myocyte beta-adrenergic responsiveness was reduced by 25% in the supraventricular tachycardia group with no change in the control group. In the presence of 40 and 80 micrograms/ml of protamine, myocyte contractile function decreased in both groups. However, 40 micrograms/ml of protamine caused a more pronounced decline in myocyte function and beta-adrenergic responsiveness in the supraventricular tachycardia group.
CONCLUSIONS
An increased sensitivity to the depressive effects of protamine on myocyte contractile function and beta-adrenergic responsiveness occurred in this model of chronic left ventricular dysfunction. These results suggest that patients with underlying cardiac disease may have an increased susceptibility to a sudden compromise of left ventricular contractile performance after protamine administration.
Topics: Animals; Cardiomyopathy, Dilated; Heparin; In Vitro Techniques; Myocardial Contraction; Myocardium; Protamines; Receptors, Adrenergic, beta; Swine; Ventricular Dysfunction, Left
PubMed: 7860928
DOI: 10.1016/0735-1097(94)00429-T -
Scandinavian Cardiovascular Journal :... Dec 2019Protamine reduces platelet aggregation after cardiopulmonary bypass (CPB). We studied the inhibitory effect of a reduced protamine dose, the duration of impaired...
Protamine reduces platelet aggregation after cardiopulmonary bypass (CPB). We studied the inhibitory effect of a reduced protamine dose, the duration of impaired platelet function and the possible correlation to postoperative bleeding. Platelet function was assessed by impedance aggregometry in 30 patients undergoing cardiac surgery with CPB at baseline, before protamine administration, after 70% and 100% of the calculated protamine dose, after 20 minutes and at arrival to the intensive care unit. Adenosine diphosphate (ADP), thrombin receptor activating peptide-6 (TRAP), arachidonic acid (AA) and collagen (COL) were used as activators. Blood loss was measured during operation and three hours after surgery. Results are presented as median (25th-75th percentile). Platelet aggregation decreased markedly after the initial dose of protamine (70%) with all activators; ADP 89 (71-110) to 54 (35-78), TRAP 143 (116-167) to 109 (77-136), both < .01; AA 25 (16-49) to 17 (12-24) and COL 92 (47-103) to 60 (38-81) U, both < .05. No further decrease was seen after 100% protamine. The effect was transient and after twenty minutes platelet aggregation had started to recover; ADP 76 (54-106), TRAP 138 (95-158), AA 20 (10-35), COL 70 (51-93) U. Blood loss during operation correlated to aggregometry measured at baseline and after protaminization. Protamine after CPB induces a marked decrease in platelet aggregation already at a protamine-heparin ratio of 0.7:1. The impairment seems to be transient and recovery had started after 20 minutes.
Topics: Aged; Blood Loss, Surgical; Cardiopulmonary Bypass; Coronary Artery Bypass; Dose-Response Relationship, Drug; Erythrocyte Transfusion; Female; Heart Valve Prosthesis Implantation; Heparin Antagonists; Humans; Male; Middle Aged; Platelet Aggregation; Platelet Function Tests; Postoperative Hemorrhage; Protamines; Time Factors; Treatment Outcome
PubMed: 31476919
DOI: 10.1080/14017431.2019.1659396 -
Scientific Reports Oct 2015Several studies have investigated the association between polymorphisms in protamine 1 and 2 genes and male infertility risk, with inconsistent results to date. This... (Meta-Analysis)
Meta-Analysis
Several studies have investigated the association between polymorphisms in protamine 1 and 2 genes and male infertility risk, with inconsistent results to date. This meta-analysis based on the 13 published case-control studies, including 7350 cases and 6167 controls, was performed to further establish the potential association between the 6 common single nucleotide polymorphisms (rs35576928, rs737008, rs35262993, rs2301365, rs1646022, rs2070923) in protamines 1 and 2 and male infertility. The -190C > A (rs2301365) polymorphism was identified as a risk factor for male infertility under all models. Interestingly, rs1646022 and rs737008 polymorphisms exerted protective effects against male sterility in Asian and population-based under some models. No associations between the remaining SNPs and male sterility were observed.
Topics: Alleles; Asian People; Databases, Factual; Humans; Infertility, Male; Male; Odds Ratio; Polymorphism, Single Nucleotide; Protamines; Risk Factors
PubMed: 26472740
DOI: 10.1038/srep15300 -
Acta Biochimica Polonica 2018Here we report the industrial pollution effects due to cadmium on the reproductive health of Mytilus galloprovincialis. Mussels were removed from the biofouling of a...
Here we report the industrial pollution effects due to cadmium on the reproductive health of Mytilus galloprovincialis. Mussels were removed from the biofouling of a Conatex panel after one year exposition at a polluted site near a disposal metallurgical factory. A high cadmium bioaccumulation was observed in the testis of mussels housed at the polluted site, with respect to a control site, as determined by inductively coupled plasma-mass spectrometry, along with a 10 fold increase in metallothionein 20 kDa gene (mt20) expression levels determined by qPCR. Furthermore, mussels transferred into laboratory tanks from the reference site, and exposed to 1.5, 5 and 10 µM CdCl, revealed a 1.7, 3.2 and 4.5 fold expression increase in the testis mt20, respectively, and a positive correlation with cadmium bioaccumulation was found. To evaluate a potential detrimental risk of such alterations on spermatozoa, we carried out electrophoretic analyses on their protamine-like proteins. As determined by AU-PAGE, after 1.5 µM CdCl exposure, protamine-like proteins also display major alterations with respect to those obtained after 5 and 10 µM CdCl exposure. All protamine-like proteins isolated from the polluted biofouling were in an aggregated form and displayed the same reduced DNA binding affinity of the protamine-like proteins obtained after 1.5 µM CdCl as demonstrated EMSA with sperm genomic DNA. Our results contribute to the studies concerning cadmium induced testis alterations and highlight protamine-like proteins' analysis as an emerging biotechnique for cadmium impact assessment on Mytilus galloprovincialis, for the sensitivity of the in vivo and in vitro changes of protamine-like proteins' state and their DNA binding affinity.
Topics: Animals; Cadmium; DNA; Male; Metallothionein; Mytilus; Protamines; Reproduction; Testis; Water Pollutants, Chemical
PubMed: 29906296
DOI: 10.18388/abp.2017_2533 -
Journal of Healthcare Engineering 2022In this study, we have evaluated and examined various nursing effects of improved administration of protamine sulfate neutralizing heparin after cardiopulmonary bypass....
In this study, we have evaluated and examined various nursing effects of improved administration of protamine sulfate neutralizing heparin after cardiopulmonary bypass. For this purpose, retrospective analysis was made about the nursing records and clinical data of 216 patients who underwent cardiac operation under cardiopulmonary bypass in our hospital from January 2018 to December 2020. Among the enrolled patients, 118 patients were given subinterval administration of protamine sulfate neutralizing heparin via aortic root with the assistance of the scrub nurse at the end of cardiac surgery (improved group). A total of 98 patients were administered by the circulating nurse via the central vein (regular group). The changes of body temperature, blood pressure, oxygen saturation before and after heparin neutralization, and the total volume of thoracic drainage within 24 hours after operation were observed in the two groups, so as to evaluate the application effect of the improved administration of protamine sulfate neutralizing heparin from the perspective of nursing. There was no significant difference in age, gender, and other basic characteristics between the two groups ( > 0.05). The volume of drainage in the improved group and the regular group within 24 hours after surgery was 234 ± 26.3 ml and 307 ± 31.8 ml, respectively, < 0.01, and the difference was statistically significant. The incidence of adverse reactions in the improved group was much lower than that in the regular group, < 0.01. The administration route of the improved group was beneficial to maintain the stability of hemodynamics when using the protamine sulfate to neutralize heparin, which is worthy of clinical nursing promotion.
Topics: Cardiac Surgical Procedures; Cardiopulmonary Bypass; Heparin; Humans; Protamines; Retrospective Studies
PubMed: 35299687
DOI: 10.1155/2022/9334113