ABSTRACT
Objective To study the relationship between IP 3 and detrusor cell contraction mediated by M 3R. Methods [3H]-IP contents of human cultured detrusor cells were detected after stimulated by carbachol,atropine,methoctramine and 4-DAMP respectively. Results [3H]-IP contents increased with carbachol concentration.On the different concentrations (10 -9、10 -8、10 -7、10 -6、10 -5、10 -4 mmol/L )of 4-DAMP,[3H]-IP contents were 3 926.57?273.29、2 780.52?211.09、2436.84?153.62、1 973.22?164.71、1 372.38?141.35 and 1 107.98?920.45 cpm respectively.On the some concertrations of Atropine,[3H]-IP contents were 3 602.69?280.17,2 891.31?207.45,1 983.97?145.74,1 269.57? 105.31,1 106.37?75.23,927.50?77.36/min,respectively.On the same concentrations of methoctramine, the [3H]-IP contents was 4 462.74?360.69、3 938.61?327.13、3 315.45?270.36、3 063.19? 246.79、2927.37?226.45 and 2 836.55?241.63 cpm.This donoted that 4-DAMP and atropine signficantly inhibited the effect of carbachol on PI decomposition(P0.05). Conclusions M 3R is much related to IP 3.
ABSTRACT
Objective To investigate the molecular mechanisms of beta3 adrenoceptor subtypes mediating rat detrusor relaxation. Methods Cyclic adenosine monophosphate(cAMP) was detected by radioimmunoassay, the effects of the cyclic AMP inhibitor SQ 22,536 and the cyclic AMP dependent protein kinase inhibitor H 89 on the relaxation elicited by ISO and BRL37344A in the rat ditrusor were investigated based on pharmacological evaluations. Results After the stimulating of ? AR by ISO, the levels of intracellular cAMP was increased, and the relaxation mediated via ISO could be partly inhibited by SQ 22,536 or H 89 The concentrations of intracellular cAMP had no changes in the presence of SQ 22,536 or H 89, and the relaxant responses to BRL37344A was not affected by SQ 22,536 or H 89. Conclusion The effects of ISO via? AR on relaxant responses to detrusor was mediated mainly by the cyclic AMP independent pathway and in part by the cyclic AMP dependent pathway, but cAMP PKA pathway were not involved in the beta3 adrenoceptor signaling pathway