Magnesium sulfate

Magnesium sulfate (MgSO₄), potassium chloride (KCl), calcium chloride (CaCl₂), glucose, sodium bicarbonate (NaHCO₃), sodium chloride (NaCl), and sodium dihydrogen phosphate (NaH₂PO₄) were purchased from Vetec Química Fina Ltda. (Brazil). Atropine (99%), (S-(−)-Bay K8644), chloride verapamil, pyrilamine, carbamylcholine hydrochloride (CCh), Cremophor®, and histamine were obtained from Sigma-Aldrich (Brazil). Carboxymethylcellulose was obtained from Formula (Brazil). Castor oil was obtained from Farmax (Brazil). Loperamide (99%) was obtained from Janssen Cilag Farmacêutica Ltd. (Brazil) and activated charcoal was obtained from Proquímicos (Brazil). All substances were diluted in distilled water, and the extract was solubilized in Cremophor^® (3%), whose concentration never exceeded 0.01% (v/v). At this concentration, this chemical is devoid of contractile or relaxant effects on the studied organ, according to previous obtained data (data not shown).

Polyethersulfone (PES, MW 58 kDa) and polyvinylpyrrolidone (PVP, MW 360 kDa) were purchased from Basf, Ludwigshafen am Rhein, Germany and Sigma-Aldrich, St. Louis, MI, USA, respectively. The common solvent for both polymers was N, N-dimethylacetamide (DMAc, 99.5%), purchased from Tedia, Fairfield, Ohio, EUA. For microbiological experiments, deionized water was supplied by a Milli-Q apparatus (Merck KGaA, Darmstadt, Germany). Yeast extract, meat peptone, and agar were purchased from Kasvi, São José do Pinhais, Brazil. Magnesium sulfate, potassium phosphate monobasic, potassium phosphate dibasic, and glycerol were purchased from Vetec, Duque de Caxias, Brazil. These reagents were used as culture medium. PES and PVP were dried at 60 °C overnight before being used and the other reagents were used as received.