Age-related neuroinflammation and pathology in the locus coeruleus and hippocampus: beta-adrenergic antagonists exacerbate impairment of learning and memory in aged mice.

The locus coeruleus (LC) provides the primary noradrenergic input to the forebrain and hippocampus, and may be vulnerable to degeneration and contribute to age-related cognitive decline and neuroinflammation. Additionally, inhibition of noradrenergic transmission by brain-permeable beta-blockers could exacerbate cognitive impairment. This study examined effects of age and acute beta-blocker administration on LC and hippocampus pathology, neuroinflammation and learning and memory behavior in mice. Male mice, 3 and 18 months old, were administered propranolol (beta-blocker) or mabuterol (beta-adrenergic agonist) acutely around behavioral assessment. Terminal inflammatory markers in plasma, hippocampus and LC were assessed alongside histopathology. An increase in hippocampal and LC microgliosis and inflammatory proteins in the hippocampus was detected in aged mice. We report pathological hyperphosphorylation of the postsynaptic NMDA receptor subunit 2B (NR2B) in the hippocampus, suggesting neuronal hyperexcitability. Furthermore, the aged proteome revealed an induction in proteins related to energy metabolism, and mitochondria dysfunction in the LC and hippocampus. In a series of hippocampal dependent behavioral assessment tasks acute beta-adrenergic agonist or beta blocker administration altered learning and memory behavior in both aged and young mice. In Y-maze, propranolol and mabuterol differentially altered time spent in novel versus familiar arms in young and aged mice. Propranolol impaired Novel Object Recognition in both young and aged mice. Mabuterol enhanced trace learning in fear conditioning. Aged mice froze more to context and less to cue. Propranolol impaired contextual recall in aged mice. Concluding, aged mice show LC and hippocampus pathology and heightened effects of beta-adrenergic pharmacology on learning and memory.

In situ immobilization of sulfated-ß-cyclodextrin as stationary phase for capillary electrochromatography enantioseparation.

In this work, a novel sulfated-ß-cyclodextrin (S-ß-CD) coated stationary phase was prepared for open-tubular capillary electrochromatography (OT-CEC). The capillary was developed by attaching polydopamine/sulfated-ß-cyclodextrin (PDA/S-ß-CD) onto the gold nanoparticles (AuNPs) coated capillary which was pretreated with polydopamine. The results of scanning electron microscopy (SEM) and energy dispersive X-ray analysis spectroscopy (EDS) indicated that polydopamine/sulfated-ß-cyclodextrin was successfully fixed on the gold nanoparticles coated capillary. To evaluate the performance of the prepared open tubular (OT) column, the enantioseparation was carried out by using ten chiral drugs as model analytes. Under the optimal conditions, salbutamol, terbutaline, trantinterol, tulobuterol, clorprenaline, pheniramine, chlorpheniramine, brompheniramine, isoprenaline and tolterodine were baseline separated with the resolution (Rs) values of 3.25, 1.76, 2.51, 1.89, 3.17, 2.17, 1.99, 1.72, 2.01 and 3.20, respectively. Repeatability of the column was studied, with the relative standard deviations for run-to-run, day-to-day and column-to-column lower than 5.7%.

Inhibitory effect of mabuterol on proliferation of rat ASMCs induced by PDGF-BB via regulating [Ca2+]i and mitochondrial fission/fusion.

This study is aimed to investigate whether Mabuterol (Mab) inhibits proliferation of airway smooth muscle cells (ASMCs) induced by platelet-derived growth factor BB (PDGF-BB) and how far it is related to mitochondrial fission/fusion and intracellular calcium if it comes into play. To explore the mechanism of Mab's antagonizing the proliferation, Mdivi-1, DRP1 inhibitor, which has an inhibitory effect on mitochondrial fission, is used to compare with Mab. Cell viability was measured by either MTT or CCK-8. The inhibitory effect of Mab on S phase of ASM cell cycle induced by PDGF-BB was analyzed by flow cytometry (FCM). Fluo-3/AM, Ca2+ fluorescent probe, was used to detect Ca2+ fluorescence intensity by inverted microscope and flow cytometry. The gene expression of Drp-1 and Mfn-2 was observed with Real time PCR and the proteins of Drp-1, Mfn-2, PCNA and cyclin D1 were assessed by Western Blot. Mab and Mdivi-1 both suppressed the proliferation induced by PDGF-BB. The results from inverted microscope and flow cytometry showed that Mab inhibited [Ca2+]i in rat ASMCs induced by PDGF-BB. Cell cycle concept map illustrated that Mab significantly controlled the S phase of ASM cell cycle induced by PDGF-BB. As a consequence, Real time PCR and Western blot revealed the fact that Mab decreased the expression of Drp-1 mRNA and protein, and promoted the expression of Mfn-2 mRNA and protein. These findings suggested that Mab placed restrictions on the proliferation of rat ASMCs induced by PDGF-BB and the mechanism might be associated with the intracellular calcium inhibited and the mitochondrial fission/fusion regulated by Mab.

Detection of ß-agonists in pork tissue with novel electrospun nanofibers-based solid-phase extraction followed ultra-high performance liquid chromatography/tandem mass spectrometry.

A selective analytical method based on packed-fiber solid-phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry (PFSPE-UPLC-MS/MS) has been developed for determination of six ß-agonists (clorprenaline, bambuterol, clenbuterol, brombuterol, mabuterol, and penbuterol) in pork tissue. Polystyrene-polymeric crown ether (PS-PCE) composite nanofibers were fabricated by electrospinning and utilized to prepare the homemade extraction columns. With optimal conditions, all analytes were separated very well and the blank pork did not disturb the determination, and the linearity is good in a range of 5.0µg/kg-25.0µg/kg. The recoveries were 79.3-110.1%. RSDs for intra-day were in the range of 1.5-10.5% and RSDs for inter-day were 4.7-11.8%. Above all, only 5mg of sorbent and 200µL of elution solvent were favorable to directly extract all analytes in a complex matrix. The method is simple and cost-effective, and has the potential to be applied to quantitatively analyze the concentrations of polar species in food samples containing complex matrix.

Synthesis of stable isotope labeled D9 -Mabuterol, D9 -Bambuterol, and D9 -Cimbuterol.

Three stable and simple synthetic routes of labeled D9 -Mabuterol, D9 -Bambuterol, and D9 -Cimbuterol were described with 98.5%, 99.7%, and 98.4% isotopic abundance and good purity. These structures and isotope-abundance were confirmed according to 1 H NMR and liquid chromatography-tandem mass spectrometry.

Efficient synthesis of D6 -clenproperol and D6 -cimaterol using deuterium isopropylamine as labelled precursor.

This report presents an efficient synthesis of D6 -clenproperol and D6 -cimaterol with 99.5% and 99.7% isotopic abundance in acceptable yields and excellent chemical purities with deuterium isopropylamine as labelled precursor. Their structures and the isotope-abundance were confirmed by proton nuclear magnetic resonance and liquid chromatography-mass spectrometry.

Quantification of trantinterol, its two metabolites and their primary conjugated metabolites in human plasma by ultra-high-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study.

A highly rapid, selective and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to simultaneously determine trantinterol, its major phase-I metabolites and their primary conjugated metabolites in human plasma. Waters Oasis HLB C18 solid phase extraction cartridges were used in the sample preparation. The separation was carried out on an ACQUITY UPLC™ BEH C18 column with methanol/0.2% formic acid (30:70, v/v) as the mobile phase at a flow rate of 0.25 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer in selective reaction monitoring (SRM) mode with the use of an electrospray ionization (ESI) source. The linear calibration curves for trantinterol, tert-butyl hydroxylated trantinterol (tert-OH-trantinterol) and 1-carbonyl trantinterol (trantinterol-COOH) were obtained in the concentration ranges of 0.200-250, 0.108-4.00 and 0.0840-5.02 ng/mL, respectively (r(2)≥0.99). The intra- and inter-day precision (relative standard deviation, RSD) values were less than 13%, and the accuracy (relative error, RE) was within ±9.9%, as determined from quality control (QC) samples for the analytes. The concentrations of conjugated forms of trantinterol and tert-OH- trantinterol in plasma were determined using selective enzyme hydrolysis. The method described herein was fully validated and successfully applied for the pharmacokinetic study of trantinterol in healthy volunteers after oral administration.

Pharmacokinetics of trantinterol and its metabolite in healthy elderly and young subjects.

OBJECTIVE: The aim of this study was to investigate and compare the pharmacokinetics of trantinterol and its active amphoteric carboxylic acid metabolite (1-carbonyl trantinterol) between the healthy elderly and young subjects. METHODS: This was a single-center, open-label, parallel-group study completed by 22 healthy subjects (≥65 years (the elderly group); 18-45 years (the young group); 9 males and 2 females per age group) receiving single oral dose of 50 µg trantinterol tablets. Blood samples were taken at intervals up to 48 hours post-dose. RESULTS: In both groups, maximum plasma concentration of trantinterol was researched at 0.9 hours, while the tmax of 1-carbonyl trantinterol differed slightly. Trantinterol Cmax and AUClast were higher in the elderly group than the young group, by 27% (90% CI, 0.95-1.69) and 77% (90% CI, 1.25-2.51), respectively. For 1-carbonyl trantinterol, Cmax, and AUClast were also higher, by 36% (90% CI, 1.04-1.78) and 71% (90% CI, 1.27-2.30), respectively, in the elderly group. The CL/F and V/F of trantinterol and 1-carbonyl trantinterol were significantly lower in the elderly group, while t1/2 of both did not show significant differences. CL/F of trantinterol and 1-carbonyl trantinterol were found to significantly correlate inversely with age, and positively with the baseline creatinine clearance. CONCLUSIONS: A single dose of 50 µg trantinterol was well tolerated. Significant changes in Cmax and AUC of trantinterol and 1-carbony trantinterol were seen in the elderly and may be clinically important.

An LC-MS/MS method for simultaneous determination of trantinterol and its major metabolite in rat plasma and its application to a comparative pharmacokinetic study.

Trantinterol is a novel ß2-adrenoceptor agonist, currently undergoing clinical trials for the treatment of asthma. We developed and validated an liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of trantinterol and its major metabolite, 1-carbonyl trantinterol (SPFFCOOH), in rat plasma. Aliquots (100µL) of heparinized plasma samples were processed by protein precipitation with acetonitrile. Chromatographic separation used an Acquity UPLC BEH C18 column (2.1mm×50mm, 1.7µm) and acetonitrile-0.1% formic acid (20:80, v/v) as mobile phase, at a flow rate of 0.25mL/min. The detection was performed on a triple-quadrupole tandem mass spectrometer with multiple-reaction monitoring (MRM) mode via electrospray ionization (ESI) source. The precursor-to-product ion transitions m/z 310.9→m/z 237.9 for trantinterol, m/z 324.9→m/z 251.9 for SPFFCOOH and m/z 368.0→m/z 294.0 for bambuterol (internal standard, IS) were used for quantification. The calibration curves were obtained in the concentration of 0.25-100ng/mL for both trantinterol and SPFFCOOH. The intra- and inter-day precision (relative standard deviations, RSD) values were below 15% and accuracy (relative error, RE) was from -4.3% to 6.6% at all quality control (QC) levels. The method was successfully applied to compare the pharmacokinetics of trantinterol and SPFFCOOH in male and female Wistar rats after a single oral administration of trantinterol.

Simultaneous quantification of trantinterol and its metabolites in human urine by ultra performance liquid chromatography-tandem mass spectrometry.

A rapid, selective and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to simultaneously determine trantinterol and its major metabolites in human urine. Waters Oasis HLB C18 solid phase extraction cartridges were used in the urine sample preparation. The separation was carried out on an ACQUITY UPLC™ BEH C18 column with methanol-0.2% formic acid (30:70, v/v) as the mobile phase at a flow rate of 0.25mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. The linear calibration curves for trantinterol, arylhydroxylamine trantinterol (N-OH-trantinterol), the tert-butyl hydroxylated trantinterol (tert-OH-trantinterol) and the 1-carbonyl trantinterol (trantinterol-COOH) were obtained in the concentration range of 0.414-207, 0.578-385, 0.168-84.0, and 0.954-477ng/mL, respectively. The linear correlation coefficients were greater than 0.990. The intra and inter-day precision (relative standard deviation, RSD) values were less than 12% and the accuracy (relative error, RE) was 6.7-11%. The method herein described was superior to previous methods in sample throughput and sensitivity and successfully applied to the human excretion study.