Jutamaad SatayavivadUdom ChantharaksriYupin SanvarindaApinya Thiantanawat2025-02-032025-02-03198820251988Thesis (M.Sc. (Pharmacology))--Mahidol University, 1988https://repository.li.mahidol.ac.th/handle/20.500.14594/103194Pharmacology (Mahidol University 1988)The contraction of tracheal smooth muscle is controlled by the parasympathetic nervous system. This effect is mediated by activation of muscarinic receptor and is completely antagonized by atropine which is a muscarinic receptor antagonist. In this study, the rat tracheal muscarinic response was tested after the animals were treated with the drug that affected the formation of arachidonic acid metabolites. Steroidal antiinflammatory durg like prednisolone which is phospholipase A(,2) inhibitor and non-steroidal anti-inflammatory drugs eg. aspirin and indomethacin which have the inhibitory activity for cyclooxygenase were used in order to detect their effects on rat tracheal muscarinic responses. From the results, indomethacin and prednisolone caused hyposensitivity of muscarinic response whereas hypersensitivity of muscarinic response was observed in rat treated with ASA dose 150 mg/kg body weight. Lipoxygenase is an another important enzyme in arachidonic acid metabolism. Gossypol, the natural substance that found in cotton seed and root bark, was a Chinese folk medicine for chronic bronchitis, but it was not as wellknown as its effect as a male contraceptive. Gossypol was selected in this study because of its lipoxygenase inhibitory property. The results showed that animals that were pretreated with gossypol 14 h. before sacrifice developed the decrease in tracheal muscarinic responses. Since this drug has to be taken for a long time for it clinical uses, therefore, the effect of gossypol on muscarinic responses were tested after 7 and 21 days pretreatment at the dose range of 1-10 mg/kg/day. The results showed that 7 days pretreatment with gossypol induced the hyposensitivity in muscarinic responses. It was found that the degree of hyposensitivity is depended on the doses of gossypol. The highest reduction (50%) in rat tracheal muscarinic response was observed when gossypol 10 mg/kg/day was used. In 21 days pretreated groups, the hyposensitivity in muscarinic response was not observed. From this study, it was concluded that drugs which affected the formation of arachidonic acid metabotites could modify rat tracheal muscarinic responses. These alterations in muscarinic responses can occur as hyper or hyposensitivity depended on types and doses of drugs that affect types and amounts of arachidonate metabolites formation.xii, 111 leaves : ill.application/pdfengผลงานนี้เป็นลิขสิทธิ์ของมหาวิทยาลัยมหิดล ขอสงวนไว้สำหรับเพื่อการศึกษาเท่านั้น ต้องอ้างอิงแหล่งที่มา ห้ามดัดแปลงเนื้อหา และห้ามนำไปใช้เพื่อการค้าArachidonic acids -- MetabolismAspirinGossypolMuscle, SmoothReceptors, CholinergicReceptors, MuscarinicTracheaMaster ThesisMahidol University