| 1. |
- Adner, Mikael, et al.
(författare)
-
Budesonide Prevents Cytokine-Induced Decrease of the Relaxant Responses to Formoterol and Terbutaline, but Not to Salmeterol, in Mouse Trachea
- 2010
-
Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0103 .- 0022-3565. ; 333:1, s. 273-280
-
Tidskriftsartikel (refereegranskat)abstract
- During asthma exacerbations, increased airway inflammation may impair the effects of beta(2)-adrenoceptor (beta(2)AR) agonists. It is unclear whether this impairment is prevented by inhaled glucocorticoids (GCs). We have investigated the relaxation of carbachol-contracted mouse tracheal segments to the beta(2)AR agonists formoterol, terbutaline, and salmeterol. The segments were pre-exposed for 4 days to the proinflammatory cytokines tumor necrosis factor alpha (100 ng/ml) and interleukin-1 beta (10 ng/ml) with or without the GC, budesonide (1 mu M). Formoterol and terbutaline induced greater maximal relaxation (R-max)than salmeterol. The cytokines decreased R-max of all beta(2)AR agonists, whereas budesonide had no effect. However, after concomitant treatment with cytokines and budesonide, the R-max values of formoterol and terbutaline were not impaired, whereas budesonide did not prevent the decrease in the R-max of salmeterol. A similar pattern was observed for cAMP production by the agonists. In tracheal smooth muscle, beta(2)AR mRNA was not affected by the cytokines but increased with budesonide. However, the cytokines markedly increased cyclooxygenase (COX)-2 mRNA expression, which may lead to heterologous desensitization of beta(2)AR. It is noteworthy that the cytokine-induced increase of COX-2 was blocked by concomitant budesonide suggesting that heterologous desensitization of beta(2)AR by the cytokines may be prevented by budesonide treatment. Budesonide prevented cytokine-induced impairment of the tracheal relaxation and beta(2)AR/cAMP signaling for formoterol but not for salmeterol. This suggests that differences exist between formoterol and salmeterol in beta(2)AR coupling/activation and/or signal transduction upstream of cAMP. These results imply that maximal bronchodilator effects of formoterol, but not of salmeterol, are maintained by budesonide treatment during periods with increased inflammation, such as asthma exacerbations.
|
|
| 2. |
- Ammoun, Sylwia, et al.
(författare)
-
Distinct Recognition of OX1 and OX2 Receptors by Orexin Peptides
- 2003
-
Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0022-3565 .- 1521-0103. ; 305:2, s. 507-514
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, we have compared the abilities of orexin-A and orexin-B and variants of orexin-A to activate different Ca(2+) responses (influx and release) in human OX(1) and OX(2) receptor- expressing Chinese hamster ovary cells. Responses mediated by activation of both receptor subtypes with either orexin-A or -B were primarily dependent on extracellular Ca(2+), suggesting similar activation of Ca(2+) influx as we have previously shown for orexin-A and OX(1) receptors. Amino acid-wise truncation of orexin-A reduced its ability to activate OX(1) and OX(2) receptors, but the response mediated by the OX(2) receptor was more resistant to truncation than the response mediated by the OX(1) receptor. We also performed a sequential replacement of amino acids 14 to 26 with alanine in the truncated orexin-A variant orexin-A(14-33). Replacement of the same amino acids produced a fall in the potency for each receptor subtype, but the reduction was less prominent for the OX(2) receptor. The most marked reduction was produced by the replacement of Leu20, Asp25, and His26 with alanine. Interestingly, extracellular Ca(2+) dependence of responses to some of the mutated peptides was different from those of orexin-A and -B. The mutagenesis also suggests that although the determinants required from orexin-A for binding to and activation of the receptor are highly conserved between the orexin receptor subtypes, the OX(2) receptor requires fewer determinants. This might in part explain why orexin-B has the affinity and potency equal to orexin-A for this subtype, although it has 10- to 100-fold lower affinity and potency for the OX(1) receptor.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Boger, Elin, et al.
(författare)
-
A Novel In Vivo Receptor Occupancy Methodology for the Glucocorticoid Receptor : Toward An Improved Understanding of Lung Pharmacokinetic/Pharmacodynamic Relationships
- 2015
-
Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0022-3565 .- 1521-0103. ; 353:2, s. 279-287
-
Tidskriftsartikel (refereegranskat)abstract
- Investigation of pharmacokinetic/pharmacodynamic (PK/PD) relationships for inhaled drugs is challenging because of the limited possibilities of measuring tissue exposure and target engagement in the lung. The aim of this study was to develop a methodology for measuring receptor occupancy in vivo in the rat for the glucocorticoid receptor (GR) to allow more informative inhalation PK/PD studies. From AstraZeneca's chemical library of GR binders, compound 1 [N-(2-amino-2-oxo-ethyl)-3-[5-[(1R,2S)-2-(2,2-difluoropropanoylamino)-1-(2,3-dihydro-1,4-benzodioxin-6-yl) propoxy] indazol-1-yl]-N-methyl-benzamide] was identified to have properties that are useful as a tracer for GR in vitro. When given at an appropriate dose (30 nmol/kg) to rats, compound 1 functioned as a tracer in the lung and spleen in vivo using liquid chromatography-tandem mass spectrometry bioanalysis. The methodology was successfully used to show the dose-receptor occupancy relationship measured at 1.5 hours after intravenous administration of fluticasone propionate (20, 150, and 750 nmol/kg) as well as to characterize the time profile for receptor occupancy after a dose of 90 nmol/kg i.v. The dose giving 50% occupancy was estimated as 47 nmol/kg. The methodology is novel in terms of measuring occupancy strictly in vivo and by using an unlabeled tracer. This feature confers key advantages, including occupancy estimation not being influenced by drug particle dissolution or binding/dissociation taking place postmortem. In addition, the tracer may be labeled for use in positron emission tomography imaging, thus enabling occupancy estimation in humans as a translatable biomarker of target engagement.
|
|
| 8. |
- Casselbrant, Anna, 1970, et al.
(författare)
-
Luminal Polyethylene Glycol Alleviates Intestinal Preservation Injury Irrespective of Molecular Size
- 2018
-
Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0022-3565 .- 1521-0103. ; 366:1, s. 29-36
-
Tidskriftsartikel (refereegranskat)abstract
- Intestinal preservation injury (IPI) and the resulting mucosa injury raise several serious challenges early after intestinal transplantation. The current clinical approach using only vascular perfusion allows the shortest preservation period among the abdominal organs. The experimental addition of luminal polyethylene glycol (PEG) solutions has been repeatedly suggested to alleviate preservation injury, improve graft quality, and prolong the preservation time. We investigated whether the molecular mass of PEG in solution influences the development of intestinal preservation injury. Small intestines of Sprague-Dawley rats were perfused with University of Wisconsin solution. Group 1 underwent vascular perfusion only (clinical control), group 2 received additional luminal PEG3350 Da, group 3 received luminal PEG10000 Da, and group 4 received luminal PEG20000 Da (n = 8/group). Tissue samples were obtained after 4, 8, and 14 hours. We studied the tissue damage (Chiu/Park score, Goblet cells, apoptosis, tight junctions), activation of c-Jun NH2-terminal kinase (JNK), and p38-mitogen-activated protein kinase (MAPK), and we performed Ussing chamber assessments. Mucosal morphologic and electrophysiologic parameters were significantly improved in the groups receiving luminal PEG. There was significantly less apoptotic activity in groups 2, 3, and 4. Both MAPKs revealed an activation peak after 4 hours with group 3 showing lesser p38-MAPK activation. PEG 20 kDa interfered with protein immunodetection. The results indicate that luminal solutions of PEG of medium and large molecular mass significantly delay the onset and development of IPI, providing further evidence that luminal interventions may allow for longer cold storage intervals of intestinal grafts.
|
|
| 9. |
|
|
| 10. |
|
|
