We examined the relation of Cook and Medley Hostility (Ho) scores to alpha- and beta-adrenergic receptor responsiveness to pharmacological agonists in 22 normotensive and 14 hypertensives (aged 18-34) white males, matched for age and body mass. alpha-Adrenergic receptor responsiveness was measured by the phenylephrine dose required to increase mean blood pressure by 25 mmHg (PD25). beta-Adrenergic responsiveness was measured by the isoproterenol dose needed to increase heart rate by 25 bpm (CD25), and to lower systemic vascular resistance by 40% (VD40). Relative to men with low Ho scores (< or = 21), men with high Ho scores (> or = 21) showed significantly reduced vascular beta 2-adrenergic receptor responsiveness (VD40). Moreover, the decreased vascular responsiveness was more pronounced in borderline hypertensive men with high Ho scores. Ho scores were also marginally significant in predicting cardiac beta 1- and beta 2-adrenergic receptor responsiveness, such that men with high Ho scores showed decreased responsiveness as indexed by a larger CD25. Vascular alpha 1-adrenergic responsiveness was not associated with hostility. These observations suggest that hostility, alone or in conjunction with BP status, is associated with reduced cardiovascular beta-adrenergic receptor responsiveness.