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Parecoxib is neuroprotective in spontaneously hypertensive rats after transient middle cerebral artery occlusion: a divided treatment response?

Kelsen J, Kjaer K, Chen G, Pedersen M, Røhl L, Frøkiaer J, Nielsen S, Nyengaard JR, Rønn LC - J Neuroinflammation (2006)

Bottom Line: We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03).We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected.IP parecoxib administration during tMCAo was neuroprotective, as evidenced by a large reduction in mean infarct volume and a lower cortical ADC increment.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Water and Salt Research Centre, University of Aarhus, DK-8000 Aarhus C, Denmark. jesper.kelsen@ki.au.dk

ABSTRACT

Background: Anti-inflammatory treatment affects ischemic damage and neurogenesis in rodent models of cerebral ischemia. We investigated the potential benefit of COX-2 inhibition with parecoxib in spontaneously hypertensive rats (SHRs) subjected to transient middle cerebral artery occlusion (tMCAo).

Methods: Sixty-four male SHRs were randomized to 90 min of intraluminal tMCAo or sham surgery. Parecoxib (10 mg/kg) or isotonic saline was administered intraperitoneally (IP) during the procedure, and twice daily thereafter. Nineteen animals were euthanized after 24 hours, and each hemisphere was examined for mRNA expression of pro-inflammatory cytokines and COX enzymes by quantitative RT-PCR. Twenty-three tMCAo animals were studied with diffusion and T2 weighted MRI within the first 24 hours, and ten of the SHRs underwent follow-up MRI six days later. Thirty-three SHRs were given 5-bromo-2'-deoxy-uridine (BrdU) twice daily on Day 4 to 7 after tMCAo. Animals were euthanized on Day 8 and the brains were studied with free-floating immunohistochemistry for activated microglia (ED-1), hippocampal granule cell BrdU incorporation, and neuronal nuclei (NeuN). Infarct volume estimation was done using the 2D nucleator and Cavalieri principle on NeuN-stained coronal brain sections. The total number of BrdU+ cells in the dentate gyrus (DG) of the hippocampus was estimated using the optical fractionator.

Results: We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03). Cortical ADC values in the parecoxib group were markedly less increased on Day 8 (p < 0.01). Interestingly, the parecoxib treated rats were segregated into two subgroups, suggesting a responder vs. non-responder phenomenon. We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected. Hippocampal granule cell BrdU incorporation was not affected by parecoxib treatment. Presence of ED-1+ activated microglia in the hippocampus was related to an increase in BrdU uptake in the DG.

Conclusion: IP parecoxib administration during tMCAo was neuroprotective, as evidenced by a large reduction in mean infarct volume and a lower cortical ADC increment. Increased pro-inflammatory cytokine mRNA levels and hippocampal granule cell BrdU incorporation remained unaffected.

No MeSH data available.


Related in: MedlinePlus

Schematic maps of animal experiments. The course of tMCAo and sham surgery is shown in 1A. Note that all animals were anesthetized nearly 160 minutes while they underwent surgery. Parecoxib (10 mg/kg BW) or isotonic saline was administered IP within the first five minutes after the start of tMCAo or sham. 1B illustrates steps in the qRT-PCR part of the study. Only half of the animals subjected to tMCAo underwent MRI prior to euthanasia. 1C shows complete drug administration plan in the neurogenesis part. Buprenorphine (0.03 mg/kg BW) was given IM as a pain killer for the first two days twice daily. Parecoxib (10 mg/kg BW) or isotonic saline was injected IP twice daily throughout the investigation period. Finally, BrdU (50 mg/kg BW) was administered IP at 7 am and 3 pm on Day 4 to Day 7. Six tMCAo animals randomized to parecoxib treatment and four SHRs receiving isotonic saline commenced MRI on both Day 2 and Day 8.
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Figure 1: Schematic maps of animal experiments. The course of tMCAo and sham surgery is shown in 1A. Note that all animals were anesthetized nearly 160 minutes while they underwent surgery. Parecoxib (10 mg/kg BW) or isotonic saline was administered IP within the first five minutes after the start of tMCAo or sham. 1B illustrates steps in the qRT-PCR part of the study. Only half of the animals subjected to tMCAo underwent MRI prior to euthanasia. 1C shows complete drug administration plan in the neurogenesis part. Buprenorphine (0.03 mg/kg BW) was given IM as a pain killer for the first two days twice daily. Parecoxib (10 mg/kg BW) or isotonic saline was injected IP twice daily throughout the investigation period. Finally, BrdU (50 mg/kg BW) was administered IP at 7 am and 3 pm on Day 4 to Day 7. Six tMCAo animals randomized to parecoxib treatment and four SHRs receiving isotonic saline commenced MRI on both Day 2 and Day 8.

Mentions: Anesthesia induction was accomplished within two minutes in a chamber filled with 5% isoflurane (Baxter Isoflurane, Baxter Medical) in a 35/65% oxygen (O2) and nitrous oxide (N2O) atmosphere. Following weighing and shaving, the animals were placed in supine position on a heating pad and allowed to breathe spontaneously through a facemask. Isoflurane was decreased to 1.0–1.5% and administered continuously in the O2/N2O mixture at a flow rate of 1 L/min. The depth of anesthesia was assessed with toe pinching and on the basis of arterial blood gas parameters. An intramuscular (IM) injection of atropine (Atropin SAD, 0.05 mg/kg BW) was given to reduce mucus production during anesthesia. The incision sites were infiltrated with a subcutaneous injection of bupivacaine (Bupivacain SAD, 2.5 mg/ml) (Figure 1A).


Parecoxib is neuroprotective in spontaneously hypertensive rats after transient middle cerebral artery occlusion: a divided treatment response?

Kelsen J, Kjaer K, Chen G, Pedersen M, Røhl L, Frøkiaer J, Nielsen S, Nyengaard JR, Rønn LC - J Neuroinflammation (2006)

Schematic maps of animal experiments. The course of tMCAo and sham surgery is shown in 1A. Note that all animals were anesthetized nearly 160 minutes while they underwent surgery. Parecoxib (10 mg/kg BW) or isotonic saline was administered IP within the first five minutes after the start of tMCAo or sham. 1B illustrates steps in the qRT-PCR part of the study. Only half of the animals subjected to tMCAo underwent MRI prior to euthanasia. 1C shows complete drug administration plan in the neurogenesis part. Buprenorphine (0.03 mg/kg BW) was given IM as a pain killer for the first two days twice daily. Parecoxib (10 mg/kg BW) or isotonic saline was injected IP twice daily throughout the investigation period. Finally, BrdU (50 mg/kg BW) was administered IP at 7 am and 3 pm on Day 4 to Day 7. Six tMCAo animals randomized to parecoxib treatment and four SHRs receiving isotonic saline commenced MRI on both Day 2 and Day 8.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1764728&req=5

Figure 1: Schematic maps of animal experiments. The course of tMCAo and sham surgery is shown in 1A. Note that all animals were anesthetized nearly 160 minutes while they underwent surgery. Parecoxib (10 mg/kg BW) or isotonic saline was administered IP within the first five minutes after the start of tMCAo or sham. 1B illustrates steps in the qRT-PCR part of the study. Only half of the animals subjected to tMCAo underwent MRI prior to euthanasia. 1C shows complete drug administration plan in the neurogenesis part. Buprenorphine (0.03 mg/kg BW) was given IM as a pain killer for the first two days twice daily. Parecoxib (10 mg/kg BW) or isotonic saline was injected IP twice daily throughout the investigation period. Finally, BrdU (50 mg/kg BW) was administered IP at 7 am and 3 pm on Day 4 to Day 7. Six tMCAo animals randomized to parecoxib treatment and four SHRs receiving isotonic saline commenced MRI on both Day 2 and Day 8.
Mentions: Anesthesia induction was accomplished within two minutes in a chamber filled with 5% isoflurane (Baxter Isoflurane, Baxter Medical) in a 35/65% oxygen (O2) and nitrous oxide (N2O) atmosphere. Following weighing and shaving, the animals were placed in supine position on a heating pad and allowed to breathe spontaneously through a facemask. Isoflurane was decreased to 1.0–1.5% and administered continuously in the O2/N2O mixture at a flow rate of 1 L/min. The depth of anesthesia was assessed with toe pinching and on the basis of arterial blood gas parameters. An intramuscular (IM) injection of atropine (Atropin SAD, 0.05 mg/kg BW) was given to reduce mucus production during anesthesia. The incision sites were infiltrated with a subcutaneous injection of bupivacaine (Bupivacain SAD, 2.5 mg/ml) (Figure 1A).

Bottom Line: We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03).We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected.IP parecoxib administration during tMCAo was neuroprotective, as evidenced by a large reduction in mean infarct volume and a lower cortical ADC increment.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Water and Salt Research Centre, University of Aarhus, DK-8000 Aarhus C, Denmark. jesper.kelsen@ki.au.dk

ABSTRACT

Background: Anti-inflammatory treatment affects ischemic damage and neurogenesis in rodent models of cerebral ischemia. We investigated the potential benefit of COX-2 inhibition with parecoxib in spontaneously hypertensive rats (SHRs) subjected to transient middle cerebral artery occlusion (tMCAo).

Methods: Sixty-four male SHRs were randomized to 90 min of intraluminal tMCAo or sham surgery. Parecoxib (10 mg/kg) or isotonic saline was administered intraperitoneally (IP) during the procedure, and twice daily thereafter. Nineteen animals were euthanized after 24 hours, and each hemisphere was examined for mRNA expression of pro-inflammatory cytokines and COX enzymes by quantitative RT-PCR. Twenty-three tMCAo animals were studied with diffusion and T2 weighted MRI within the first 24 hours, and ten of the SHRs underwent follow-up MRI six days later. Thirty-three SHRs were given 5-bromo-2'-deoxy-uridine (BrdU) twice daily on Day 4 to 7 after tMCAo. Animals were euthanized on Day 8 and the brains were studied with free-floating immunohistochemistry for activated microglia (ED-1), hippocampal granule cell BrdU incorporation, and neuronal nuclei (NeuN). Infarct volume estimation was done using the 2D nucleator and Cavalieri principle on NeuN-stained coronal brain sections. The total number of BrdU+ cells in the dentate gyrus (DG) of the hippocampus was estimated using the optical fractionator.

Results: We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03). Cortical ADC values in the parecoxib group were markedly less increased on Day 8 (p < 0.01). Interestingly, the parecoxib treated rats were segregated into two subgroups, suggesting a responder vs. non-responder phenomenon. We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected. Hippocampal granule cell BrdU incorporation was not affected by parecoxib treatment. Presence of ED-1+ activated microglia in the hippocampus was related to an increase in BrdU uptake in the DG.

Conclusion: IP parecoxib administration during tMCAo was neuroprotective, as evidenced by a large reduction in mean infarct volume and a lower cortical ADC increment. Increased pro-inflammatory cytokine mRNA levels and hippocampal granule cell BrdU incorporation remained unaffected.

No MeSH data available.


Related in: MedlinePlus