1999 Volume 22 Issue 5 Pages 453-456
New thienothiazine derivatives which differ in their side chain on the nitrogen atom of the thienothiazine molecule were studied in guinea pig papillary muscles and terminal ilea using isometric contraction force measurements. Compounds with a heterocyclic ring in their side chain like MS 57 (pyrrolidinylethylcarboxamide side chain), MS 58 (piperidinoethylcarboxamide side chain) and MS 55 (morpholinoethylcarboxamide side chain) had the most potent negative inotropic effect on isolated paplillary muscles. The relaxing effect on smooth muscle was more pronounced with compounds carrying an aromatic ring in their side chain like MS 25(dimethoxyphenylethyl-N-aminopropionyl side chain), MS 24 (dimethoxyphenylethyl-N-methylaminoacetyl side chain) and MS 27 (dimethoxyphenyl-N-methylethylaminoethylcarboxamide side chain). Our results show a tissue selectivity of the thienothiazine compounds.
