Evaluation of platelet thromboxane radioimmunoassay method to measure platelet life-span: Comparison with /sup 111/indium-platelet method
The platelet activation during radiolabeling in vitro with Cr-51 and In-111 may affect the platelet life-span (PLS) in vivo. A new RIA method to measure PLS is being evaluated. Aspirin inhibits platelet thromboxane (TxA/sub 2/) by acetylating cyclooxygenase. The time required for the TxA/sub 2/ levels to return towards control values depends on the rate of new platelets entering circulation and is a measure of PLS. A single dose of aspirin (150mg) was given to 5 normal human subjects. Blood samples were collected for 2 days before aspirin and daily for 10 days. TxA/sub 2/ production in response to endogenous thrombin was studied by allowing 1 ml blood sample to clot at 37/sup 0/C for 90 min. Serum TxB/sub 2/ (stable breakdown product of Tx-A/sub 2/) levels determined by RIA technique. The plot of TxB/sub 2/ levels (% control) against time showed a gradual increase. The PLS calculated by linear regression analysis assuming a 2-day lag period before cyclooxygenase recovery is 9.7 +- 2.37. In the same 5 subjects, platelets from a 50ml blood sample were labeled with /sup 111/In-tropolone in 2 ml autologous plasma. Starting at 1 hr after injection of labeled platelets, 10 blood samples were obtained over a 8 day period. The PLS calculated based on a linear regression analysis is 10.2 +. 1.4. The PLS measured from the rate of platelet disappearance from circulation and the rate of platelet regeneration into circulation are quite comparable in normal subjects. TxA/sub 2/ regeneration RIA may provide a method to measure PLS without administering radioactivity to patient.
- Research Organization:
- Mt. Sinai Medical Center, New York, NY
- OSTI ID:
- 6856658
- Report Number(s):
- CONF-850611-; TRN: 87-010617
- Journal Information:
- J. Nucl. Med.; (United States), Vol. 26:5; Conference: 32. annual meeting of the Society of Nuclear Medicine, Houston, TX, USA, 2 Jun 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACETYLSALICYLIC ACID
BIOLOGICAL EFFECTS
BLOOD PLATELETS
LABELLING
PROSTAGLANDINS
CHEMICAL PREPARATION
RETENTION FUNCTIONS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL HALF-LIFE
CHROMIUM 51
DATA ANALYSIS
EVALUATION
IN VIVO
INDIUM 111
RADIOIMMUNOASSAY
ANALGESICS
ANTIPYRETICS
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
CHROMIUM ISOTOPES
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
FUNCTIONS
HYDROXY ACIDS
IMMUNOASSAY
IMMUNOLOGY
INDIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MATERIALS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
RADIOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
REACTION KINETICS
SYNTHESIS
TRACER TECHNIQUES
550601* - Medicine- Unsealed Radionuclides in Diagnostics