title: Effect of endothelin on regional hemodynamics and renal function in awake normotensive rats.
abstract: The effects of endothelin on regional hemodynamics and renal function were studied in awake normotensive rats. Intravenous injection of endothelin (700 pmol/kg) transiently lowered mean blood pressure (from 108 +/- 2 to 84 +/- 2 mm Hg, p less than 0.01), due to a reduction in total vascular resistance (38 +/- 1%, p less than 0.01), and increased stroke volume (29 +/- 5%, p less than 0.01) and heart rate (from 399 +/- 18 to 447 +/- 18 bpm, p less than 0.05); mesenteric and renal blood flow was reduced (37 +/- 13, p less than 0.05 and 63 +/- 5%, p less than 0.01), whereas carotid blood flow was increased (78 +/- 5%, p less than 0.01). This effect was followed by long-lasting hypertension due to increased total vascular resistance (112 +/- 19%, p less than 0.01); stroke volume, mesenteric, and renal blood flow were reduced (34 +/- 5, 41 +/- 4, and 58 +/- 4%, respectively, p less than 0.05) and carotid blood flow returned to basal levels. Bilateral nephrectomy enhanced the initial hypotensive effect. Pretreatment with nifedipine blocked the hypertensive effect, whereas bilateral nephrectomy did not. A subpressor dose of endothelin (70 pmol/kg) had no effect on stroke volume, mesenteric blood flow, glomerular filtration rate, and plasma renin activity; carotid blood flow was transiently increased (48 +/- 16%, p less than 0.05), then returned to basal levels; renal blood flow decreased (22 +/- 6 and 15 +/- 4% at 30 s and 10 min, respectively p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
authors: Department of Patologia Medica, University of Sassari, Italy.
authors: P
authors: P
authors: Madeddu
authors: C
authors: C
authors: Troffa
authors: N
authors: N
authors: Glorioso
authors: A
authors: A
authors: Pazzola
authors: A
authors: A
authors: Soro
authors: P
authors: P
authors: Manunta
authors: G
authors: G
authors: Tonolo
authors: M P
authors: MP
authors: Demontis
authors: M V
authors: MV
authors: Varoni
authors: V
authors: V
authors: Anania
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D016232:Endothelins; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D007668:Kidney / Q000098:blood supply / Q000187:drug effects*; D007677:Kidney Function Tests; D009392:Nephrectomy; D009638:Norepinephrine / Q000494:pharmacology; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology*; D011188:Potassium / Q000652:urine; D051381:Rats; D012039:Regional Blood Flow / Q000187:drug effects; D012083:Renin / Q000097:blood; D012212:Rheology; D012964:Sodium / Q000652:urine
chemical_list: D016232:Endothelins; D010455:Peptides; D000804:Angiotensin II; D012964:Sodium; D012083:Renin; D011188:Potassium; D009638:Norepinephrine