In vivo, ex vivo, and in vitro studies on apelin's effect on myocardial glucose uptake

Peptides ◽  
2012 ◽  
Vol 37 (2) ◽  
pp. 320-326 ◽  
Author(s):  
Shiming Xu ◽  
Pei Han ◽  
Mei Huang ◽  
Joseph C. Wu ◽  
Chingpin Chang ◽  
...  
2000 ◽  
Vol 83 (05) ◽  
pp. 752-758 ◽  
Author(s):  
Claude Le Feuvre ◽  
Annie Brunet ◽  
Thuc Do Pham ◽  
Jean-Philippe Metzger ◽  
André Vacheron ◽  
...  

SummaryThe 3-morpholinosydnonimine (SIN-1) generates both nitric oxide (NO) and superoxide anion (O2−). It elicits dose-dependent vasodilation in vivo, in spite of the opposite effects of its breakdown products on vascular tone and platelet aggregation.This study was designed to investigate the influence of intravenous SIN-1 injection on platelet Ca2+ handling in patients undergoing coronary angiography. SIN-1 administration reduced cytosolic [Ca2+] in unstimulated platelets by decreasing Ca2+ influx. It attenuated Ca2+ mobilization from internal stores evoked by thrombin or thapsigargin. In vitro studies were used as an approach to investigate how simultaneous productions of NO and O2− from SIN-1 modify thrombin- or thapsigargin-induced platelet Ca2+ mobilization. Superoxide dismutase, the O2− scavenger, enhanced the capacity of SIN-1 to inhibit Ca2+ mobilization but catalase had no effect.This suggests that the effects of SIN-1 on platelet Ca2+ handling resemble those of NO, but are modulated by simultaneous O2− release, independently of H2O2 formation.


2021 ◽  
Vol 16 (1) ◽  
pp. 211-118
Author(s):  
Venkatesh S ◽  
Aswani K ◽  
Asheena Asharaf V V ◽  
Anjitha P ◽  
Suresh A ◽  
...  

The present study has been undertaken to evaluate the in-vitro, in-vivo and ex-vivo anti-diabetic activity of leaves of chloroform extract Clerodendrum paniculatum (CECP). The extract was prepared by soxhlet extraction. Phytochemical screening indicates the presence of flavonoids, phenols, carbohydrates etc. The anti-diabetic activity of extract was studied by in-vitro (alpha amylase inhibition and alpha glucosidase inhibition assay), in-vivo (streptozotocin induced diabetes) and ex-vivo (glucose uptake by rat hemi - diaphragm method). For in-vitro studies, the inhibitory action of CECP was compared with standard drug Acarbose. The IC50 values of CECP for alpha amylase and alpha glucosidase was found to be 158.396 µg/ml and 113.122 µg/ml respectively and the extract shows significant anti-diabetic activity. For in-vivo and ex-vivo studies Glibenclamide was used as a standard drug to compare the blood glucose level and uptake of glucose was calculated. The results obtained from the study indicate that both 200 mg/kg and 400 mg/kg of CECP showed significant anti-diabetic activity. The 400 mg/kg of CECP showed better activity when compared to 200 mg/kg of the extract. The glucose uptake study was performed by isolated rat hemidiaphragm method. The hemi diaphragm obtained from the rats treated with both the doses of CECP showed significant glucose uptake.


2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.


1992 ◽  
Vol 68 (06) ◽  
pp. 687-693 ◽  
Author(s):  
P T Larsson ◽  
N H Wallén ◽  
A Martinsson ◽  
N Egberg ◽  
P Hjemdahl

SummaryThe significance of platelet β-adrenoceptors for platelet responses to adrenergic stimuli in vivo and in vitro was studied in healthy volunteers. Low dose infusion of the β-adrenoceptor agonist isoprenaline decreased platelet aggregability in vivo as measured by ex vivo filtragometry. Infusion of adrenaline, a mixed α- and β-adrenoceptor agonist, increased platelet aggregability in vivo markedly, as measured by ex vivo filtragometry and plasma β-thromboglobulin levels. Adrenaline levels were 3–4 nM in venous plasma during infusion. Both adrenaline and high dose isoprenaline elevated plasma von Willebrand factor antigen levels β-Blockade by propranolol did not alter our measures of platelet aggregability at rest or during adrenaline infusions, but inhibited adrenaline-induced increases in vWf:ag. In a model using filtragometry to assess platelet aggregability in whole blood in vitro, propranolol enhanced the proaggregatory actions of 5 nM, but not of 10 nM adrenaline. The present data suggest that β-adrenoceptor stimulation can inhibit platelet function in vivo but that effects of adrenaline at high physiological concentrations are dominated by an α-adrenoceptor mediated proaggregatory action.


1979 ◽  
Vol 41 (03) ◽  
pp. 465-474 ◽  
Author(s):  
Marcia R Stelzer ◽  
Thomas S Burns ◽  
Robert N Saunders

SummaryThe relationship between the effects of suloctidil in vivo as an antiplatelet agent and in vitro as a modifier of platelet serotonin (5-HT) parameters was investigated. Suloctidil was found to be effective in reducing platelet aggregates formation in the retired breeder rat as determined using the platelet aggregate ratio method (PAR) with an ED50 of 16.1 mg/kg 24 hours post administration. In contrast to the hypothesis that 5-HT depletion is involved in the anti-aggregatory mechanism of suloctidil, no correlation was found between platelet 5- HT content and this antiplatelet activity. Reduction of platelet 5-HT content required multiple injections of high doses (100 mg/kg/day) of suloctidil. Suloctidil administration for 8 days at 100 mg/kg/day, which lowered platelet 5-HT content by 50%, resulted in no permanent effect on ex vivo platelet 5-HT uptake or thrombin-induced release, nor alteration in the plasma 5-HT level. However, these platelets exhibited a short-lived, significant increase in percent leakage of 5-HT after 30 minutes of incubation. Therefore, suloctidil treatment at high doses may with time result in platelet 5-HT depletion, however this effect is probably not related to the primary anti-aggregatory activity of the drug.


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