PURPOSE: The incidence of acute myocardial infarctions (AMI) shows circadian variation typically peaking during morning hours with a decline at night. However, this variation does not occur in patients with diabetes mellitus (DM). The night's decline of AMI may be partially explained by melatonin-related platelet inhibition. Whether this effect is absent in diabetic patients is unknown. The aim was to study the effect of melatonin on in-vitro platelet aggregation in healthy individuals and patients with type 2 DM. METHODS: Platelet aggregation was measured in blood samples from healthy individuals (n = 15) and type 2 DM patients (n = 15) using multiple electrode aggregometry. Adenosine diphosphate (ADP), arachidonic acid (ASPI) and thrombin (TRAP) were used as agonists. Aggregability for each subject was tested after adding melatonin in two concentrations. RESULTS: In healthy individuals, melatonin inhibited platelet aggregation in both higher (10-5 M) and lower concentrations (10-9 M) induced by ADP, ASPI, and TRAP (p < 0.001, p = 0.002, p = 0.029, respectively). In DM patients, melatonin did not affect platelet aggregation in both concentrations induced by ADP, ASPI, and TRAP. Melatonin decreased platelet aggregation induced by ADP, ASPI, and TRAP significantly more in healthy individuals compared to patients with DM. (p = 0.005, p = 0.045 and p = 0.048, respectively). CONCLUSION: Platelet aggregation was inhibited by melatonin in healthy individuals. In-vitro antiplatelet effect of melatonin in type 2 DM patients is significantly attenuated.
- MeSH
- adenosindifosfát farmakologie MeSH
- agregace trombocytů fyziologie MeSH
- diabetes mellitus 2. typu * farmakoterapie MeSH
- infarkt myokardu * MeSH
- inhibitory agregace trombocytů farmakologie terapeutické užití MeSH
- lidé MeSH
- melatonin * farmakologie terapeutické užití MeSH
- trombocyty fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Cardiovascular diseases including hypertension are often associated with behavioural alterations. The aim of this study was to show, whether ivabradine, the blocker of If-channel in sinoatrial node, is able to modify the behaviour of rats in L-nitro-arginine methyl ester (L-NAME)-induced hypertension and to compare the effect of ivabradine with captopril and melatonin. 12-week-old male Wistar rats were divided into the following groups: controls, ivabradine (10 mg/kg/24 h), L-NAME (40 mg/kg/24 h), L-NAME + ivabradine, L-NAME + captopril (100 mg/kg/24 h), L-NAME + melatonin (10 mg/kg/24 h). Systolic blood pressure (SBP) and heart rate (HR) were measured by tail-cuff method once a week. The behaviour of rats was investigated during 23-hours in the phenotyper after four weeks of the treatment. Chronic administration of L-NAME induced hypertension without a change in HR. All tested substances partly prevented the increase of SBP, while ivabradine and melatonin also reduced HR. Ivabradine, captopril and melatonin reduced daily food intake, slightly decreased daily water intake and attenuated body weight gain. In L-NAME group, locomotor activity was enhanced by ivabradine, whereas exploratory behaviour was increased by melatonin and captopril. In conclusion, ivabradine, besides its potentially protective hemodynamic actions, does not seem to exert any disturbing effects on behaviour in L-NAME-induced hypertension in rats, while some of its effects were similar to captopril or melatonin. It is suggested that ivabradine used in cardiovascular indications is harmless regarding the effect on behaviour.
- MeSH
- antihypertenziva farmakologie MeSH
- benzazepiny farmakologie MeSH
- chování zvířat účinky léků MeSH
- hypertenze farmakoterapie metabolismus MeSH
- inhibitory ACE farmakologie MeSH
- kaptopril farmakologie MeSH
- krevní tlak účinky léků MeSH
- krysa rodu rattus MeSH
- lokomoce účinky léků MeSH
- melatonin farmakologie MeSH
- NG-nitroargininmethylester metabolismus MeSH
- oxid dusnatý metabolismus MeSH
- potkani Wistar MeSH
- srdeční frekvence účinky léků MeSH
- synthasa oxidu dusnatého metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- financování organizované MeSH
- Publikační typ
- abstrakty MeSH
- MeSH
- C-peptid analýza krev MeSH
- diabetes mellitus diagnóza MeSH
- glukagon aplikace a dávkování diagnostické užití MeSH
- krevní glukóza analýza MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- kongresy MeSH
- MeSH
- C-peptid analýza krev MeSH
- diabetes mellitus 1. typu diagnóza MeSH
- glukagon aplikace a dávkování diagnostické užití MeSH
- krevní glukóza analýza MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- kongresy MeSH
- srovnávací studie MeSH
- MeSH
- C-peptid analýza krev MeSH
- diabetes mellitus 1. typu diagnóza MeSH
- diabetické nefropatie diagnóza MeSH
- glukagon aplikace a dávkování diagnostické užití MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- kongresy MeSH
- MeSH
- albuminurie MeSH
- albuminy MeSH
- diabetes mellitus 2. typu komplikace moč MeSH
- dospělí MeSH
- glomerulus patofyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- proteinurie MeSH
- senioři MeSH
- transferin moč MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- MeSH
- diabetické angiopatie genetika MeSH
- inhibitory ACE MeSH
- polymorfismus genetický MeSH
- Publikační typ
- kongresy MeSH
