Development of a RIA for clonidine and its comparison with the reference methods

Arndts, D.; Stähle, H.; Förster, H.

doi:10.1016/0160-5402(81)90069-3

Cited by 54 publications

(11 citation statements)

References 4 publications

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“…Numerous analytical methods, including radioimmunoassay (Arndts et al, 1981), HPLC (Rosansky et al, 1993), GC (Chu et al, 1979;Edlund, 1980;Nazarali et al, 1986;Velasquez et al, 1983), GC/MS (Arrendale et al, 1988;Girault and Fourtillan, 1988;Murray et al, 1981;Murray and Davies, 1984;Wenzl et al, 2002;Yamahata et al, 1994), LC-MS (Ke et al, 2004) and LC-MS/MS (Muller et al, 2007;Naidong et al, 2002) have been reported in the literature to quantify clonidine in biological fluids. None of these methods could reliably quantify clonidine concentration lower than 50 pg/ mL.…”

Section: Introductionmentioning

confidence: 98%

Liquid chromatography tandem mass spectrometry method for the quantification of clonidine with LLOQ of 10 pg/mL in human plasma

Nirogi

Kandikere

Mudigonda

et al. 2008

Biomedical Chromatography

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A sensitive high-performance liquid chromatography-positive ion electrospray tandem mass spectrometry method was developed and validated for the quantification of clonidine in human plasma. Following liquid-liquid extraction, the analytes were separated using an isocratic mobile phase on a reverse-phase column and analyzed by MS/MS in the multiple reaction monitoring mode using the respective [M + H](+) ions, m/z 230 to 44 for clonidine and m/z 254 to 44 for the internal standard. The assay exhibited a linear dynamic range of 10-2000 pg/mL for clonidine in human plasma. The lower limit of quantification was 10 pg/mL with a relative standard deviation of less than 6.8%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 2.5 min for each sample made it possible to analyze more than 250 human plasma samples per day. The validated method was successfully used to analyze human plasma samples for application in pharmacokinetic studies.

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Section: Introductionmentioning

confidence: 98%

Liquid chromatography tandem mass spectrometry method for the quantification of clonidine with LLOQ of 10 pg/mL in human plasma

Nirogi

Kandikere

Mudigonda

et al. 2008

Biomedical Chromatography

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“…Clonidine was measured by radioimmunoassay as previously described [3]. Plasma sodium was determined by a Model 343 flame photometer (Instrumentation Laboratories).…”

Section: Methodsmentioning

confidence: 99%

Clonidine Decreases Plasma and Cerebrospinal Fluid Arginine Vasopressin but Not Oxytocin in Humans

et al. 1987

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To evaluate the oα-noradrenergic regulation of arginine vasopressin (AVP) and oxytocin (OT) in normal humans, we measured the effect of the α₂-agonist clonidine on concentrations of these neuropeptides in both plasma and cerebrospinal fluid (CSF). Subjects underwent two lumbar puncture studies, one of which was performed 100 min after oral administration of 5 µg/kg clonidine. Plasma AVP and OT were measured at a single time point 10 min before lumbar puncture. Both plasma and CSF AVP were significantly lower in the clonidine condition than in the control (no drug) condition. Neither plasma nor CSF OT differed significantly between conditions. Our data confirm previous reports of α₂-noradrenergic inhibition of neurohypophyseal release of AVP into blood, and extend these findings to healthy human subjects. Our data also suggest that AVP appearance in CSF, presumably from extraneurohypophyseal vasopressinergic neurons, is regulated by an inhibitory oα-noradrenergic mechanism.

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“…(12)(13)(14)(15). Assays with these antibodies were conducted as usually described for drug-specific RIAs: (a) accuracy was determined with biological fluids (serum, urine) with added known levels of drugs; (b) so-called "matrix effects" were abolished in the assays by dilutions of analytical samples in biological fluids identical to those used for calibration curves, except that they were drug free; (c) specificity of RIAs was generally assessed by determining cross-reactivities of drug metabolites; (d) pharmacokinetics in human plasma were studied after oral or intravenous administration of clonidine.…”

Section: Resultsmentioning

confidence: 99%

A circulating substance cross-reacting with antiimidazoline antibodies. Detection in serum in relation to essential hypertension.

Dontenwill

Molines²,

Verdun³

et al. 1993

J. Clin. Invest.

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It has been shown in various mammal species that clonidine, a well known centrally acting hypotensive agent, acts through the activation of imidazoline receptors (IRs) in the nucleus reticularis lateralis (NRL) of the brainstem. Specific binding sites sensitive to imidazolines and insensitive to catecholamines have been detected in rat and bovine, as well as human brains. An endogenous ligand, other than catecholamines, should exist for these IRs. Such a ligand could play a role in the pathophysiology of human essential hypertension. Therefore, we developed two RIAs with polyclonal and monoclonal anticlonidine antibodies. These antibodies presented specificity spectra similar to that of the IRs: they bound imidazolines and not catecholamines at all. These RIAs were used to detect imidazoline-like immunoreactivity in the human serum. Immunoreactive substance was measured in 26 normotensive subjects' sera, and specificity of interaction between antibodies and sera was verified. None of the known endogenous substances tested so far were able to interact with the two antibodies. Immunoreactivity in 32 essential hypertensive patients' sera proved higher in -30% of cases. Values of immunoreactivity positively correlated with the mean arterial pressure values. This study demonstrates the existence of an "imidazoline-like" immunoreactive substance in the human serum with high levels in some hyper-

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Development of a RIA for clonidine and its comparison with the reference methods

Cited by 54 publications

References 4 publications

Liquid chromatography tandem mass spectrometry method for the quantification of clonidine with LLOQ of 10 pg/mL in human plasma

Liquid chromatography tandem mass spectrometry method for the quantification of clonidine with LLOQ of 10 pg/mL in human plasma

Clonidine Decreases Plasma and Cerebrospinal Fluid Arginine Vasopressin but Not Oxytocin in Humans

A circulating substance cross-reacting with antiimidazoline antibodies. Detection in serum in relation to essential hypertension.

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