Hemodynamic responses to leukotriene receptor stimulation in conscious rats
| Autor: | D. E. Allen, M. Gellai |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Male
Cardiac output medicine.medical_specialty Time Factors Leukotriene D4 Consciousness Physiology Hemodynamics Vascular permeability Hematocrit chemistry.chemical_compound Physiology (medical) Internal medicine Animals Medicine Dicarboxylic Acids Receptors Immunologic Receptors Leukotriene Dose-Response Relationship Drug medicine.diagnostic_test business.industry Leukotriene receptor Rats Inbred Strains Rats Blood pressure Endocrinology chemistry Renal blood flow SRS-A business |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 258:R1034-R1041 |
| ISSN: | 1522-1490 0363-6119 |
| DOI: | 10.1152/ajpregu.1990.258.4.r1034 |
| Popis: | We evaluated the effects of leukotrienes (LTs) C4 and D4 on systemic and renal hemodynamics in conscious rats. Intravenous injections of LTC4 or LTD4 (0.5-10 micrograms/kg) caused dose-dependent decreases in cardiac output (CO), renal blood flow (RBF), and heart rate (HR). Flow alterations were accompanied by increased systemic and renal vascular resistances (SVR and RVR) and mean arterial blood pressure (MAP). No secondary hypotensive effect was observed. The HR response was biphasic, with tachycardia replacing the initial brief bradycardia. The changes in RBF and CO were not concurrent; the maximum RBF decrease (47.6 +/- 9.5%, P less than 0.05) occurred when CO was down only by 9.1 +/- 3.6% (P less than 0.05) and RBF had fully recovered in 3-4 min, while CO was still down by 26.3 +/- 3.5% (P less than 0.001). Hematocrit (HCT) increased after the injection of 5 and 10 micrograms/kg doses of LTC4 or LTD4, and its time course of recovery to basal level (30-60 min) paralleled that of CO. Sustained intravenous infusion of the selective LT receptor antagonist, SK&F 104353, dose-dependently inhibited the immediate hemodynamic changes after LTD4 injections. SK&F 104353 also attenuated the increase in vascular permeability and the prolonged decrease in CO, suggesting that the observed cardiac and vascular effects of LTs were mediated by stimulation of LT receptors. |
| Databáze: | OpenAIRE |
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