Angiotensin II (Ang II) is a critical component of the reninangiotensin system that contributes to hypertension. Although platelets in blood from hypertensive subjects have an abnormal biological profile, it is unclea...Angiotensin II (Ang II) is a critical component of the reninangiotensin system that contributes to hypertension. Although platelets in blood from hypertensive subjects have an abnormal biological profile, it is unclear if circulating Ang II influences platelet aggregation or thrombus formation. One of the abnormalities presented to the platelets during hypertension is an elevated plasma concentration of serotonin (5-HT) caused by reduced 5-HT uptake secondary to loss of the 5-HT transporter (SERT) on the platelet plasma membrane. In the current study, we evaluated in vivo platelet function after 7 days of subcutaneous Ang II infusion to establish hypertension in mice and additionally assessed the biology of isolated platelets exposed to Ang II in vitro. The administration of Ang II elevated systolic blood pressure, but markers of platelet activation including P-selectin and PEJon/A staining were not changed. However, the aggregation response to collagen was reduced in isolated platelets from Ang II-infused mice, which also showed reduced 5-HT uptake by SERT. In vitro exposure of isolated platelets to Ang II also resulted in a loss of surface SERT associated with a reduced aggregation response to collagen. These abnormalities were reversed by increasing concentra tions of the Ang II receptor antagonist, valsartan. Interestingly, SERT KO mice failed to fully develop hypertension in response to Ang II infusion and isolated platelets from these animals were insensitive to the anti-aggregatory influence of Ang II. Thus, Ang II blunts the aggregation responses of platelets and the mechanism underlying this action may involve a loss of SERT on the platelet plasma membrane. The latter event depletes intracellular 5-HT in platelets, an event that is associated with reduced aggregation. The widespread use of antihypertensive drugs that target the renin-angiotensin system suggest the potential clinical utility of our findings and emphasize the importance of understanding the impact of Ang II on platelet function.展开更多
The effects of different modified atmospheres (air: atm1;100% CO2: atm2;100% N2: atm3;50% CO2/50% N2: atm4) on the textural and sensory characteristics of the ready-to-serve pizza at 7℃ ± 1℃ were investigated. ...The effects of different modified atmospheres (air: atm1;100% CO2: atm2;100% N2: atm3;50% CO2/50% N2: atm4) on the textural and sensory characteristics of the ready-to-serve pizza at 7℃ ± 1℃ were investigated. The values of hardness, gumminess and chewiness were found to be increased during the storage period while cohesiveness and springiness exhibited a decreasing trend. Overall, the 100% CO2 product yielded the best textural and sensorial characteristics followed by 50%CO2/50% N2 and 100% N2 when compared to conventional packed pizza at 7℃ ± 1℃. Carbon dioxide caused microbial inhibition as well. The shelf life of ready-to-serve pizza significantly increased upto 45 days (a 300% increase) for the samples packaged under 100% CO2 (atm2), 50% CO2/50% N2 (atm4) and 100% N2 (atm3), compared to conventional air pack (15 days).展开更多
文摘Angiotensin II (Ang II) is a critical component of the reninangiotensin system that contributes to hypertension. Although platelets in blood from hypertensive subjects have an abnormal biological profile, it is unclear if circulating Ang II influences platelet aggregation or thrombus formation. One of the abnormalities presented to the platelets during hypertension is an elevated plasma concentration of serotonin (5-HT) caused by reduced 5-HT uptake secondary to loss of the 5-HT transporter (SERT) on the platelet plasma membrane. In the current study, we evaluated in vivo platelet function after 7 days of subcutaneous Ang II infusion to establish hypertension in mice and additionally assessed the biology of isolated platelets exposed to Ang II in vitro. The administration of Ang II elevated systolic blood pressure, but markers of platelet activation including P-selectin and PEJon/A staining were not changed. However, the aggregation response to collagen was reduced in isolated platelets from Ang II-infused mice, which also showed reduced 5-HT uptake by SERT. In vitro exposure of isolated platelets to Ang II also resulted in a loss of surface SERT associated with a reduced aggregation response to collagen. These abnormalities were reversed by increasing concentra tions of the Ang II receptor antagonist, valsartan. Interestingly, SERT KO mice failed to fully develop hypertension in response to Ang II infusion and isolated platelets from these animals were insensitive to the anti-aggregatory influence of Ang II. Thus, Ang II blunts the aggregation responses of platelets and the mechanism underlying this action may involve a loss of SERT on the platelet plasma membrane. The latter event depletes intracellular 5-HT in platelets, an event that is associated with reduced aggregation. The widespread use of antihypertensive drugs that target the renin-angiotensin system suggest the potential clinical utility of our findings and emphasize the importance of understanding the impact of Ang II on platelet function.
文摘The effects of different modified atmospheres (air: atm1;100% CO2: atm2;100% N2: atm3;50% CO2/50% N2: atm4) on the textural and sensory characteristics of the ready-to-serve pizza at 7℃ ± 1℃ were investigated. The values of hardness, gumminess and chewiness were found to be increased during the storage period while cohesiveness and springiness exhibited a decreasing trend. Overall, the 100% CO2 product yielded the best textural and sensorial characteristics followed by 50%CO2/50% N2 and 100% N2 when compared to conventional packed pizza at 7℃ ± 1℃. Carbon dioxide caused microbial inhibition as well. The shelf life of ready-to-serve pizza significantly increased upto 45 days (a 300% increase) for the samples packaged under 100% CO2 (atm2), 50% CO2/50% N2 (atm4) and 100% N2 (atm3), compared to conventional air pack (15 days).
