Life Sciences, cilt.322, 2023 (SCI-Expanded)
Aims: Interstitial cystitis/painful bladder syndrome (IC/PBS) is characterized by lower abdominal pain and increased frequency and urgency of urine. Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid that plays role in calcium homeostasis in smooth muscle. The intracellular calcium mobilizing secondary messengers are also involved in smooth muscle contraction. The role of intracellular calcium storing depots in S1P-induced contraction was investigated in permeabilized detrusor smooth muscle having cystitis. Main methods: IC/PBS was induced by cyclophosphamide injection. The detrusor smooth muscle strips isolated from rats were permeabilized with β-escin. Key findings: S1P-induced contraction was increased in cystitis. S1P-induced enhanced contraction was inhibited by cyclopiazonic acid, ryanodine and heparin showing involvement of sarcoplasmic reticulum (SR) calcium stores. Inhibition of S1P-induced contraction by bafilomycin and NAADP suggested the participation of lysosome-related organelles. Significance: IC/PBS triggers S1P-induced increase in intracellular calcium from SR and lysosome-related organelles in permeabilized detrusor smooth muscle.