Changes of organ blood flow and cardiac output after imidazole administration.
Effects of imidazole, an inhibitor of thromboxane synthesis (10 mg/kg bw., iv.) on the distribution of cardiac output and intrarenal hemodynamics were investigated in normovolemic (free water and salt uptake before the experiment) narcotized rats. The cardiac output was measured on the basis of the Stewart-Hamilton principle, the blood flow of the organs by the Sapirstein method. 86Rb was used as indicator. One hour following the imidazole administration while mean arterial blood pressure remained constant a slight drop in the cardiac output (CO) was observed (CO-control: 24.1 +/- 4.77; CO-imidazole: 20.6 +/- 2.40 ml/min/100 g; p < 0.05) and total peripheral resistance increased (TPR-control: 42.3 +/- 9.27; TPR-imidazole: 48.3 +/- 7.05 R; p < 0.05). The vascular resistance in the heart, lungs (bronchial fraction), liver, spleen, intestine and adrenal glands remained unchanged. The blood flow of the skin and skeletal muscle decreased moderately, their vascular resistance increased following imidazole treatment. Inhibition of the thromboxane synthesis did not influence the renal and intrarenal (cortex and medulla) circulation, the percentile distribution of the intrarenal blood flow remained unchanged. The results suggest that TXA2 does not play a definite role in maintaining the a) vascular tone (blood flow) of different organs b) intrarenal hemodynamics (salt and water excretion) in normovolemic rats.
Hably
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Department of Physiology, Semmelweis University Medical School, Budapest, Hungary.
Györváry
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Bartha
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D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000187:drug effects; D017597:Renal Blood Flow, Effective / Q000187:drug effects; D013930:Thromboxane-A Synthase / Q000037:antagonists & inhibitors; D013931:Thromboxanes / Q000378:metabolism; D013997:Time Factors
D007093:Imidazoles; D013931:Thromboxanes; C029899:imidazole; D013930:Thromboxane-A Synthase