Pinacidil

The drugs used were: acetylcholine (ACh) as chloride, indomethacin (Indo), N(ω)-nitro-l-arginine methyl ester (l-NAME) hydrochloride, noradrenaline (NA) as hydrochloride, sodium nitroprusside (SNP), tricarbonyldichlororuthenium (II) dimer (CORM-2) (Sigma-Aldrich, Schnelldorf, Germany) and pinacidil (Cayman Chemical, Hamburg, Germany). Indomethacin was dissolved in ethanol. NA was dissolved in a mixture of sodium chloride + ascorbic acid (0.9% and 0.01% w/v, respectively). Other drugs were prepared in distilled water. The stock solutions (10 mM) were maintained at −20 °C, and appropriate dilutions were made in Krebs-Henseleit solution (KHS; mM; NaCl 115, CaCl₂ 2.5, KCl 4.6, KH₂PO₄ 1.2, MgSO₄ 1.2, NaHCO₃ 25 and glucose 11.1 at pH 7.4) on the day of the experiment.
Cytochrome c, dimethyl-sulfoxide (DMSO), formic acid, hydrogen peroxide and thiobarbituric acid of LC-MS grade were purchased from Sigma Aldrich (St. Louis, MO, USA). Methanol (isocratic grade) and acetonitrile (LC-MS grade) were acquired from Merck (Darmstadt, Germany). All other reagents were of analytical grade and were provided by commercial suppliers.

Acetylcholine chloride, sodium nitroprusside, and noradrenaline hydrochloride were obtained from Sigma-Aldrich (St. Louise, MO, USA); potassium chloride from Chempur (Piekary Śląskie, Poland); pinacidil, NS1619, and U-46619 from Cayman Chemical (Ann Arbor, MI, USA). Stock solutions (10 mM) of these drugs were prepared in distilled water, except for noradrenaline, which was dissolved in NaCl (0.9%) + ascorbic acid (0.01% w/v) solution; pinacidil, NS-1619 were dissolved in DMSO, and U-46619 in ethanol.
These solutions were stored at −20 °C, and appropriate dilutions were made in Krebs-Henseleit solution (KH in mmol/L: NaCl 115; CaCl₂ 2.5; KCl 4.6; KH₂PO₄ 1.2; MgSO₄ 1.2; NaHCO₃ 25; glucose 11.1) on the day of the experiment. The maximal solvent concentration in the medium was less than 0.01% (vol/vol). At these concentrations, solvents did not alter the reactivity of the studied arteries.
Hemp seeds were purchased from Ekogram (Zielonki, Poland), and unrefined, cold-pressed hemp seed oil was obtained from Ol’Vita (Panków, Poland).