Investigation of the metabolism of substance P at the blood–brain barrier using LC–MS/MS

Chappa, Arvind K.; Cooper, Joshua D.; Audus, Kenneth L.; Lunte, Susan M.

doi:10.1016/j.jpba.2006.10.005

Cited by 17 publications

(8 citation statements)

References 34 publications

(35 reference statements)

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“…Enzymes that cleave SP [1][2][3][4][5][6][7][8][9][10][11] include members of the serine and metalloprotease families: angiotensin I-converting enzyme, aminopeptidase, neutral endopeptidase, dipeptidyl peptidase IV, and postproline cleaving enzyme. 13,14 Enzymes of these classes require inhibitors with specific affinity for their catalytic sites; therefore, protection of SP [1][2][3][4][5][6][7][8][9][10][11] from enzymatic degradation may require at least 2 inhibitor types. Various degradation products are derived from SP [1][2][3][4][5][6][7][8][9][10][11] and are named in accordance with the amino acids they contain.…”

Section: Kiu Kallikrein Inhibitor Units Lc-ms-msmentioning

confidence: 99%

Effects of sample handling methods on substance P concentrations and immunoreactivity in bovine blood samples

Mosher

Coetzee

Allen

et al. 2014

ajvr

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Objective—To determine the effects of protease inhibitors and holding times and temperatures before processing on the stability of substance P in bovine blood samples. Samples—Blood samples obtained from a healthy 6-month-old calf. Procedures—Blood samples were dispensed into tubes containing exogenous substance P and 1 of 6 degradative enzyme inhibitor treatments: heparin, EDTA, EDTA with 1 of 2 concentrations of aprotinin, or EDTA with 1 of 2 concentrations of a commercially available protease inhibitor cocktail. Plasma was harvested immediately following collection or after 1, 3, 6, 12, or 24 hours of holding at ambient (20.3° to 25.4°C) or ice bath temperatures. Total substance P immunoreactivity was determined with an ELISA; concentrations of the substance P parent molecule, a metabolite composed of the 9 terminal amino acids, and a metabolite composed of the 5 terminal amino acids were determined with liquid chromatography–tandem mass spectrometry. Results—Regarding blood samples processed immediately, no significant differences in substance P concentrations or immunoreactivity were detected among enzyme inhibitor treatments. In blood samples processed at 1 hour of holding, substance P parent molecule concentration was significantly lower for ambient temperature versus ice bath temperature holding conditions; aprotinin was the most effective inhibitor of substance P degradation at the ice bath temperature. The ELISA substance P immunoreactivity was typically lower for blood samples with heparin versus samples with other inhibitors processed at 1 hour of holding in either temperature condition. Conclusions and Clinical Relevance—Results suggested that blood samples should be chilled and plasma harvested within 1 hour after collection to prevent substance P degradation.

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Section: Kiu Kallikrein Inhibitor Units Lc-ms-msmentioning

confidence: 99%

Effects of sample handling methods on substance P concentrations and immunoreactivity in bovine blood samples

Mosher

Coetzee

Allen

et al. 2014

ajvr

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“…Special considerations must be made to remove the high salt concentrations of the dialysate sample prior to analysis to minimize ion suppression (62). Microdialysis sampling with LC-MS analysis was used to investigate the metabolism of substance P in the neurovascular space and compare it with the metabolism of the peptide by bovine BMVECs (63). Using LC-MS, researchers can employ deuterated calibrators for more accurate quantitation of brain extracellular concentrations.…”

Section: In Vivo Methods For Studying Transport Of Substances Acromentioning

confidence: 99%

“…Chappa et al (63, 87) investigated substance P transport across a BBMEC monolayer, employing LC-MS/MS for peptide quantitation. One advantage of the LC-MS method over CE-LIF is the ability to investigate the effects of lower substance P concentrations on BBB transport owing to improved limits of detection.…”

Section: In Vitro Models Of the Blood-brain Barriermentioning

confidence: 99%

“…The BBB can also act as a significant metabolic barrier for the delivery of peptides into the brain. The metabolism of substance P by enzymes present at the BBB was also investigated using the BBMEC model and LC-MS analysis (63). Figure 10 shows the products of substance P degradation by the BBB as a function of time.…”

Section: In Vitro Models Of the Blood-brain Barriermentioning

confidence: 99%

“…The time course and appearance of each SP metabolite are shown. Reprinted with permission from Reference 63.…”

Section: Figurementioning

confidence: 99%

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Analytical and Biological Methods for Probing the Blood-Brain Barrier

Sloan

Nandi

Linz³

et al. 2012

Annual Rev. Anal. Chem.

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The blood-brain barrier (BBB) is an important interface between the peripheral and central nervous systems. It protects the brain against the infiltration of harmful substances and regulates the permeation of beneficial endogenous substances from the blood into the extracellular fluid of the brain. It can also present a major obstacle in the development of drugs that are targeted for the central nervous system. Several methods have been developed to investigate the transport and metabolism of drugs, peptides, and endogenous compounds at the BBB. In vivo methods include intravenous injection, brain perfusion, positron emission tomography, and microdialysis sampling. Researchers have also developed in vitro cell-culture models that can be employed to investigate transport and metabolism at the BBB without the complication of systemic involvement. All these methods require sensitive and selective analytical methods to monitor the transport and metabolism of the compounds of interest at the BBB.

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Investigation of the metabolic biotransformation of substance P in liver microsomes by liquid chromatography quadrupole ion trap mass spectrometry

Pailleux

Lemoine

Beaudry

2012

Biomedical Chromatography

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Substance P (SP) belongs to the tachykinin family and plays an essential role in pain transmission and in neurogenic inflammation. It can be detected in the central and peripheral nervous systems. The objectives of this study were to establish SP metabolic stability in liver microsomes in three species (rat, mouse and human), and identify and characterize SP metabolites by LC-MS/MS. Endogenous peptide metabolism is not well documented and this is particularly true for neuropeptides participating in neurogenic inflammation. In vitro, T(1/2) results in pooled liver microsomes were 9.2, 5.6 and 18.6 min for rat, mouse and human liver microsomes, respectively. Five major SP metabolites were identified and quantified, including C-terminal SP fragments SP(3-11) , SP(5-11) , SP(6-11) , SP(8-11) as well as N-terminal fragment SP(1-7) . The results suggest significant differences between species in SP metabolite concentrations. Consequently, the metabolic profile of each species is distinctive and may have a significant impact on biomolecular mechanisms involved in specific pathophysiological changes.

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Investigation of the metabolism of substance P at the blood–brain barrier using LC–MS/MS

Cited by 17 publications

References 34 publications

Effects of sample handling methods on substance P concentrations and immunoreactivity in bovine blood samples

Effects of sample handling methods on substance P concentrations and immunoreactivity in bovine blood samples

Analytical and Biological Methods for Probing the Blood-Brain Barrier

Investigation of the metabolic biotransformation of substance P in liver microsomes by liquid chromatography quadrupole ion trap mass spectrometry

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