The kinin receptors are classically involved in inflammation, pain and sepsis. The effects of the kinin B1 receptor agonist des-Arg9-bradykinin (DBK) and lipopolysaccharide (LPS) were investigated by comparing the membrane potential responses of aortic rings from transgenic rats overexpressing the kinin B1 receptor (B1R) in the endothelium (TGR(Tie2B1)) and Sprague Dawley (SD) rats. No difference in the resting membrane potential in the aorta's smooth muscle from the transgenic and SD rats was observed. The aorta rings from SD rats hyperpolarized only to LPS but not to DBK, whereas the aorta rings from TGR(Tie2B1) responded by the administration of both drugs. DBK and LPS responses were inhibited by the B1 receptor antagonist R715 and by iberiotoxin in both cases. Thapsigargin induced a hyperpolarization in the smooth muscle of SD rats that was not reversed by R715, but was reversed by iberiotoxin and this hyperpolarization was further augmented by DBK administration. These results show that the model of overexpression of vascular B1 receptors in the TGR(Tie2B1) rats represent a good model to study the role of functional B1 receptors in the absence of any pathological stimulus. The data also show that KCa channels are the final mediators of the hyperpolarizing responses to DBK and LPS. In addition, we suggest an interaction between the B1R and TLR4, since the hyperpolarization induced by LPS could be abolished in the presence of R715.
- MeSH
- aorta MeSH
- bradykinin * farmakologie MeSH
- cévní endotel MeSH
- krysa rodu rattus MeSH
- lipopolysacharidy farmakologie MeSH
- membránové potenciály MeSH
- potkani Sprague-Dawley MeSH
- potkani transgenní MeSH
- receptor bradykininu B1 * genetika MeSH
- techniky in vitro MeSH
- thapsigargin farmakologie MeSH
- toll-like receptor 4 MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Our aim was to evaluate whether endothelial overexpressing of the bradykinin B1 receptor could be associated with altered left ventricular and myocardial performance. Echocardiography and hemodynamic were employed to assess left ventricular morphology and function in Sprague Dawley transgenic rats overexpressing the endothelial bradykinin B1 receptor (Tie2B1 rats). The myocardial inotropism was evaluated on papillary muscles contracting in vitro. In Tie2B1 animals, an enlarged left ventricular cavity and lower fractional shortening coupled with a lower rate of pressure change values indicated depressed left ventricular performance. Papillary muscle mechanics revealed that both Tie2B1 and wild-type rat groups had the same contractile capacities under basal conditions; however, in transgenic animals, there was accentuated inotropism due to post-pause potentiation. Following treatment with the Arg(9)-BK agonist, Tie2B1 papillary muscles displayed a reduction in myocardial inotropism. Endothelial B1 receptor overexpression has expanded the LV cavity and worsened its function. There was an exacerbated response of papillary muscle in vitro to a prolonged resting pause, and the use of a B1 receptor agonist impairs myocardial inotropism.
- MeSH
- dysfunkce levé srdeční komory genetika metabolismus patofyziologie MeSH
- endoteliální buňky metabolismus MeSH
- fenotyp MeSH
- funkce levé komory srdeční * MeSH
- genetická predispozice k nemoci MeSH
- kontrakce myokardu * MeSH
- papilární svaly metabolismus patofyziologie MeSH
- potkani Sprague-Dawley MeSH
- potkani transgenní MeSH
- receptor bradykininu B1 genetika metabolismus MeSH
- remodelace komor MeSH
- upregulace MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Kinin-vasoactive peptides activate two G-protein-coupled receptors (R), B(1)R (inducible) and B(2)R (constitutive). Their complex role in cardiovascular diseases could be related to differential actions on oxidative stress. This study investigated impacts of B(1)R or B(2)R gene deletion in mice on the cardiac function and plasma antioxidant and oxidant status. Echocardiography-Doppler was performed in B(1)R (B(1)R(-/-)) and B(2)R (B(2)R(-/-)) deficient and wild type (WT) adult male mice. No functional alteration was observed in B(2)R(-/-) hearts. B(1)R(-/-) mice had significantly lowered fractional shortening and increased isovolumetric contraction time. The diastolic E and A waves velocity ratio was similar in all mice groups. Thus B(1)R(-/-) mice provide a model of moderate systolic dysfunction, whereas B(2)R(-/-) mice displayed a normal cardiac phenotype. Plasma antioxidant capacity (ORAC) was significantly decreased in both B(1)R(-/-) and B(2)R(-/-) mice whereas the vitamin C levels were decreased in B(2)R(-/-) mice only. Plasma ascorbyl free radical was significantly higher in B(1)R(-/-) compared to WT and B(2)R(-/-) mice. Therefore, the oxidative stress index, ascorbyl free radical to vitamin C ratio, was increased in both B(1)R(-/-) and B(2)R(-/-) mice. Hence, B(1)R and B(2)R deficiency are associated with increased oxidative stress, but there is a differential imbalance between free radical production and antioxidant defense. The interrelationship between the differential B(1)R and B(2)R roles in oxidative stress and cardiovascular diseases remain to be investigated.
- MeSH
- antioxidancia metabolismus MeSH
- biologické markery krev MeSH
- dysfunkce levé srdeční komory krev genetika metabolismus patofyziologie MeSH
- funkce levé komory srdeční * MeSH
- kontrakce myokardu * MeSH
- kyselina dehydroaskorbová analogy a deriváty krev MeSH
- myokard metabolismus MeSH
- myši inbrední C57BL MeSH
- myši kmene 129 MeSH
- myši knockoutované MeSH
- myši MeSH
- oxidační stres * MeSH
- pulzní dopplerovská echokardiografie MeSH
- receptor bradykininu B1 nedostatek genetika MeSH
- receptor bradykininu B2 nedostatek genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Hereditary angiooedema (HAE) is a life-threatening disease with poor clinical phenotype correlation with its causal mutation in the C1 inhibitor (SERPING1) gene. It is characterized by substantial symptom variability even in affected members of the same family. Therefore, it is likely that genetic factors outside the SERPING1 gene have an influence on disease manifestation. In this study, functional polymorphisms in genes with a possible disease-modifying effect, B1 and B2 bradykinin receptors (BDKR1, BDKR2), angiotensin-converting enzyme (ACE) and mannose-binding lectin (MBL2), were analysed in 36 unrelated HAE patients. The same analysis was carried out in 69 HAE patients regardless of their familial relationship. No significant influence of the studied polymorphisms in the BDKR1, BDKR2, ACE and MBL2 genes on overall disease severity, localization and severity of particular attacks, frequency of oedema episodes or age of disease onset was detected in either group of patients. Other genetic and/or environmental factors should be considered to be responsible for HAE clinical variability in Caucasians.
- MeSH
- angiotensin konvertující enzym genetika MeSH
- dospělí MeSH
- fenotyp MeSH
- hereditární angioedémy genetika patofyziologie MeSH
- lektin vázající mannosu genetika MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- receptor bradykininu B1 genetika MeSH
- receptor bradykininu B2 genetika MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
