The aim of the study was to investigate comparative contractility of isolated radial artery segments (n = 50). Phosphodiesterase inhibitor (papaverine) was used in 15 segments; dihydropyridine calcium channel antagonist (adalat) was used in 12 segments; calmodulin inhibitor (aminazine) was used in 13 segments; and "nitromixture" (5 mg verapamil hydrochloride, 2.5 mg nitroglycerine, 500-UN heparin, and 300 mL isosmotic Krebs solution) was used in 10 segments. Effect of hyposmotic solution for the morphometric properties of radial artery was analyzed in 22 arterial segments. The data didn't show statistical differences between drugs: "nitromixture" decreased tone by 100 ± 2% (n = 10), papaverine by 100 ± 11% (n = 15), adalat by 95 ± 6.1% (n = 12) and aminazine by 92 ± 11.3% (n = 13) (p > 0.05). The most effective drug in duration was adalat (n = 12, 90 ± 6.5 minutes) versus "nitromixture" (n = 10, 60 ± 9.3 minutes), papaverine (n = 15, 60 ± 4.3 minutes) and aminazine (n = 13, 50 ± 3.2 minutes) (p < 0.05).