We elucidated the role of collecting duct kinin B2 receptor (B2R) in the development of salt-sensitivity and angiotensin II (ANG II)-induced hypertension. To this end, we used a Cre-Lox recombination strategy to generate mice lacking Bdkrb2 gene for B2R in the collecting duct (Hoxb7-Cre(tg/+):Bdkrb2(flox/flox)). In 3 groups of control (Bdkrb2(flox/flox)) and 3 groups of UB(Bdkrb2-/-) mice, systolic blood pressure (SBP) responses to high salt intake (4 or 8% NaCl; HS) were monitored by radiotelemetry in comparison with standard salt diet (0.4% NaCl) prior to and during subcutaneous ANG II infusion (1000 ng/min/kg) via osmotic minipumps. High salt intakes alone for 2 weeks did not alter SBP in either strain. ANG II significantly increased SBP equally in control (121 ± 2 to 156 ± 3 mmHg) and UB(Bdkrb2-/-) mice (120 ± 2 to 153 ± 2 mmHg). The development of ANG II-induced hypertension was exacerbated by 4%HS in both control (125 ± 3 to 164 ± 5 mmHg) and UB(Bdkrb2-/-) mice (124 ± 2 to 162 ± 3 mmHg) during 2 weeks. Interestingly, 8%HS caused a more profound and earlier ANG II-induced hypertension in UB(Bdkrb2-/-) (129 ± 2 to 166 ± 3 mmHg) as compared to control (128 ± 2 to 158 ± 2 mmHg) and it was accompanied by body weight loss and increased mortality. In conclusion, targeted inactivation of B2R in the renal collecting duct does not cause salt-sensitivity; however, collecting duct B2R attenuates the hypertensive actions of ANG II under conditions of very high salt intake.

• MeSH
• angiotensin II metabolismus   MeSH
• genový knockout MeSH
• hypertenze * metabolismus   patofyziologie   MeSH
• krevní tlak * účinky léků   fyziologie   MeSH
• kuchyňská sůl škodlivé účinky   MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• receptor bradykininu B2 genetika   MeSH
• sběrací ledvinové kanálky * metabolismus   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural 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

Bradykinin can enhance skeletal muscle glucose uptake (GU), and exercise increases both bradykinin production and muscle insulin sensitivity, but bradykinin's relationship with post-exercise insulin action is uncertain. Our primary aim was to determine if the B2 receptor of bradykinin (B2R) is essential for the post-exercise increase in GU by insulin-stimulated mouse soleus muscles. Wildtype (WT) and B2R knockout (B2RKO) mice were sedentary or performed 60 minutes of treadmill exercise. Isolated soleus muscles were incubated with [(3)H]-2-deoxyglucose +/-insulin (60 or 100 microU/ml). GU tended to be greater for WT vs. B2RKO soleus with 60 microU/ml insulin (P=0.166) and was significantly greater for muscles with 100 microU/ml insulin (P<0.05). Both genotypes had significant exercise-induced reductions (P<0.05) in glycemia and insulinemia, and the decrements for glucose (~14 %) and insulin (~55 %) were similar between genotypes. GU tended to be greater for exercised vs. sedentary soleus with 60 microU/ml insulin (P=0.063) and was significantly greater for muscles with 100 microU/ml insulin (P<0.05). There were no significant interactions between genotype and exercise for blood glucose, plasma insulin or GU. These results indicate that the B2R is not essential for the exercise-induced decrements in blood glucose or plasma insulin or for the post-exercise increase in GU by insulin-stimulated mouse soleus muscle.

• MeSH
• genotyp MeSH
• inzulin lidský farmakologie   krev   metabolismus   MeSH
• kondiční příprava zvířat MeSH
• kosterní svaly metabolismus   MeSH
• krevní glukóza metabolismus   MeSH
• lidé MeSH
• myši knockoutované MeSH
• myši MeSH
• receptor bradykininu B2 genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata 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