Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 348 (1993), S. 108-112 
    ISSN: 1432-1912
    Schlagwort(e): Adenosine receptors ; A1 agonists ; A2 agonists ; Rat atria ; Rat aorta ; Bovine coronary arteries
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We investigated the negative chronotropic and vasodilating properties of new selective A1 and A2 adenosine agonists such as 2-chloro-N6-cyclopentyladenosine (CCPA) and 2-hexynyl-5′-N-ethyl-carboxamidoadenosine (2-hexynyl-NECA) as compared with reference adenosine analogues. The potency of these compounds on heart rate was assessed in the rat atrial preparation and their activity on the vascular tone was determined in both rat aorta and bovine coronary artery. CCPA was found to be the most potent At agonist of those currently available in producing negative chronotropic effects (EC50 = 8.2 nM). The A1 antagonist 8-cyclopentyl-1,3-dipropyl-xanthine (DPCPX) blocked CCPA activity in a dose-dependent manner. There was also a significant correlation between its biological effect and the affinity for A1 receptors as measured in the rat brain by [3H]-N6-cyclohexyladenosine (3[H]-CHA) binding. The A2 selective agonist 2-hexynyl-NECA showed vasodilating properties comparable with those observed with the reference compounds, CGS 21680 and NECA. EC50 values were 596 and 569 nM in rat aorta and bovine coronary artery, respectively. Moreover, the rank order of potency was similar in the two vascular districts examined, suggesting that the rat aorta is a useful model for studying the effects of adenosine derivatives on vascular tone. In addition, the potency of the compounds in inducing vasodilation was found to be correlated with their affinity for A2 receptors as measured in the rat striatum by 3[H]-CGS 21680 binding. These data further support that A1 receptors are involved in depressing cardiac activity and A2 receptors in inducing vasorelaxation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1433-7339
    Schlagwort(e): Chemotherapy Melatonin ; Myelosuppression ; Toxicity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Experimental data have suggested that the pineal hormone melatonin (MLT) may counteract chemotherapy-induced myelosuppression and immunosuppression. In addition, MLT has been shown to inhibit the production of free radicals, which play a part in mediating the toxicity of chemotherapy. A study was therefore performed in an attempt to evaluate the influence of MLT on chemotherapy toxicity. The study involved 80 patients with metastatic solid tumors who were in poor clinical condition (lung cancer: 35; breast cancer: 31; gastrointestinal tract tumors: 14). Lung cancer patients were treated with cisplatin and etoposide, breast cancer patients with mitoxantrone, and gastrointestinal tract tumor patients with 5-fluorouracil plus folates. Patients were randomised to receive chemotherapy alone or chemotherapy plus MLT (20 mg/day p.o. in the evening). Thrombocytopenia was significantly less frequent in patients concomitantly treated with MLT. Malaise and asthenia were also significantly less frequent in patients receiving MLT. Finally, stomatitis and neuropathy were less frequent in the MLT group, albeit without statistically significant differences. Alopecia and vomiting were not influenced by MLT. This pilot study seems to suggest that the concomitant administration of the pineal hormone MLT during chemotherapy may prevent some chemotherapy-induced side-effects, particularly myelosuppression and neuropathy. Evaluation of the impact of MLT on chemotherapy efficacy will be the aim of future clinical investigations.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...