Role of Extracellular Calcium and Calcium Sensitization in the Anti-Contractile Effect of Perivascular Adipose Tissue in Pregnant Rat Aorta
| Autor: | Elsie Oommen, Mabayoje A. Oriowo, Lilly Verghese, Aishah Al-Jarallah |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
medicine.medical_specialty
Serotonin Contraction (grammar) Indoles Nifedipine Pyridines chemistry.chemical_element Adipose tissue Aorta Thoracic Calcium 030226 pharmacology & pharmacy Maleimides Rats Sprague-Dawley 03 medical and health sciences 0302 clinical medicine Pregnancy Internal medicine medicine.artery medicine Extracellular Animals reproductive and urinary physiology Pharmacology Aorta Voltage-dependent calcium channel Dihydropyridine General Medicine Calcium Channel Blockers Amides Endocrinology chemistry Adipose Tissue Vasoconstriction Female 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | Pharmacology. 104(5-6) |
| ISSN: | 1423-0313 |
| Popis: | Previous studies have shown that the anti-contractile effect of the perivascular adipose tissue (PVAT) is attenuated in pregnancy. In the present investigation, we have examined the possibility that this loss of anti-contractile effect could be due to changes in calcium mobilization. PVAT exerted anti-contractile effect against 5-hydroxytryptamine (5-HT)-induced contractions of aorta segments from pregnant and non-pregnant rats and this anti-contractile effect was attenuated in segments from pregnant rats. Nifedipine (10–6 mol/L), an inhibitor of L-type dihydropyridine calcium channels, significantly reduced 5-HT-induced contraction of aorta segments from non-pregnant and pregnant rats with and without PVAT. The inhibitory effect of nifedipine against 5-HT-induced contractions was attenuated in PVAT-free aorta segments from pregnant rats. However, while PVAT reduced the effectiveness of nifedipine in aorta segments from non-pregnant rats, it partially restored the inhibitory effect of nifedipine in aorta segments from pregnant rats. Inhibitors of calcium sensitization, Y-27632 (10–6 mol/L) and GF 109203X (10–6 mol/L), significantly reduced 5-HT-induced contractions of PVAT-free aorta segments from non-pregnant and pregnant rats. Both inhibitors, however, were less effective in aorta segments from pregnant rats. The presence of PVAT reduced the effectiveness of Y-27632 and GF 109203X in aorta segments from pregnant and non-pregnant rats. Protein expression of Rho-associated protein kinase (ROCK) I and II was detected in aorta segments and PVAT from pregnant and non-pregnant rats. There was a reduction in the expression of both isoforms in aorta segments but not PVAT from pregnant rats. In addition, there was no significant difference in the expression of ROCK-I and ROCK-II in PVAT from pregnant and non-pregnant rats. We concluded that the loss of anti-contractile effect of PVAT in aorta segments from pregnant rats could be due to increased influx of extracellular calcium through nifedipine-sensitive dihydropyridine channels. |
| Databáze: | OpenAIRE |
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