» Articles » PMID: 16896802

Effect of Endothelin-1 on Erythropoietin Production in a Rat Model Under Normoxia and Functional Carbon Monoxide-induced Hypoxia

Overview
Specialty Pharmacology
Date 2006 Aug 10
PMID 16896802
Authors
Affiliations
Soon will be listed here.
Abstract

It has been hypothesized that autacoids, such as endothelin-1 (ET), may modulate erythropoietin (Epo) secretion. Therefore, we studied the effect of ET-1 infusion and of a nonselective ET(A/B) receptor antagonist on Epo secretion under carbon monoxide (CO) exposure. Anesthetized rats were supplied with room temperature air containing increasing concentrations of CO by an aerating cap. A CO-Epo dose-response curve over the range of 0.02-0.14 vol% CO was conducted. Subpressor doses of ET-1 (3 pmol/min/kg BW) and the ET(A/B) receptor antagonist LU302872 (LU; 30 mg/kg) were applied to anaesthetized rats under normoxia (controls CON, ET, LU) and following hypoxia (CO exposure; H-CON, H-ET, H-LU). Mean arterial blood pressure (MAP), glomerular filtration rate (GFR, inulin clearance), Epo and ET-1 serum concentrations (ELISA) and renal Epo mRNA (Light Cycler) were determined. The EC50 value for CO was 0.1 vol% with a 70-fold increase in Epo serum concentrations. CO exposure increased Epo serum and Epo mRNA concentrations in the expected range in all groups. None of the treatments with ET or LU influenced the effect of hypoxia on Epo serum concentrations and renal Epo mRNA content. Under hypoxia, administration of ET-1 as well as LU prevented the hypoxia-induced decrease in MAP (p<0.05). Under hypoxia, GFR was reduced by 50% except for H-LU with values comparable to normoxia. Taken together, the influence of hypoxia exceeds by far the effect of ET-1 on Epo production, irrespective of the presence or absence of exogenous ET-1. Thus, ET-1 does not appear to be a major modulator of Epo production.

References
1.
Ritthaler T, Gopfert T, Firth J, Ratcliffe P, Kramer B, Kurtz A . Influence of hypoxia on hepatic and renal endothelin gene expression. Pflugers Arch. 1996; 431(4):587-93. DOI: 10.1007/BF02191907. View

2.
Takabatake T, Ise T, Ohta K, Kobayashi K . Effects of endothelin on renal hemodynamics and tubuloglomerular feedback. Am J Physiol. 1992; 263(1 Pt 2):F103-8. DOI: 10.1152/ajprenal.1992.263.1.F103. View

3.
Wolf S, Gaschler F, Brehm S, Klaussner M, Amann K, Risler T . Endothelin-receptor antagonists in uremic cardiomyopathy. J Cardiovasc Pharmacol. 2000; 36(5 Suppl 1):S348-50. DOI: 10.1097/00005344-200036051-00101. View

4.
Freudenthaler S, Lucht I, Schenk T, Brink M, Gleiter C . Dose-dependent effect of angiotensin II on human erythropoietin production. Pflugers Arch. 2000; 439(6):838-44. DOI: 10.1007/s004249900238. View

5.
Brochu E, Lacasse S, Lariviere R, Kingma I, Grose J, Lebel M . Differential effects of endothelin-1 antagonists on erythropoietin-induced hypertension in renal failure. J Am Soc Nephrol. 1999; 10(7):1440-6. DOI: 10.1681/ASN.V1071440. View