title: Metabolic responses with endothelin antagonism in a model of insulin resistance.
abstract: Atrasentan, an endothelin antagonist, would have beneficial effects on metabolic responses in a model of insulin resistance. Zucker lean or fatty rats were maintained either on regular (lean and fatty control, n = 12) or atrasentan-treated water (5 mg/kg/d, fatty atrasentan, n = 13) for 6 weeks. There was no significant difference in water intake and body weight with the atrasentan-treated group compared with fatty controls. Although atrasentan had no effect on 3-hour fasting glucose levels, it reduced fasting insulin levels between weeks 2 and 4 of treatment by 53% (fatty control vs fatty atrasentan, P < .01). Atrasentan decreased the incremental area under the plasma glucose response curve ( Delta AUC) after a nutritionally complete meal tolerance test (MTT), by 28% in the atrasentan-treated group compared with fatty controls ( P < .05), and decreased the MTT-induced insulin Delta AUC by 63% in treated animals compared with the fatty control group ( P < .01). In addition, atrasentan significantly decreased the MTT-induced glucose-insulin index Delta AUC by 58% in treated rats compared with fatty controls ( P < .01). In summary, in the Zucker fatty rat, atrasentan significantly reduces (1) 3-hour fasting insulin levels at 4 weeks, (2) glucose and insulin MTT-induced Delta AUCs, and (3) the MTT-induced glucose-insulin index Delta AUC. These results demonstrate an improvement in hyperinsulinemia as well as in glucose tolerance and insulin sensitivity with chronic endothelin antagonism in a model of insulin resistance and suggest that chronic endothelin antagonism may have benefits in the treatment of insulin resistance and/or diabetes.
authors.affiliation: Metabolic Disease Research, Global Pharmaceutical Research and Development Division, Abbott Laboratories, Abbott Park, IL 60064-3500, USA.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Berthiaume
authors.forename: Jerry L
authors.initials: JL
authors.lastname: Wessale
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Opgenorth
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Zinker
mesh_terms: D000818:Animals; D019540:Area Under Curve; D000077868:Atrasentan; D001786:Blood Glucose / Q000032:analysis; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1 / Q000097:blood; D005230:Fatty Acids, Nonesterified / Q000097:blood; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D011759:Pyrrolidines / Q000494:pharmacology*; D051381:Rats; D011924:Rats, Zucker
chemical_list: D001786:Blood Glucose; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D011759:Pyrrolidines; D000077868:Atrasentan