- 1Regulation of anion secretion by adrenoceptors in primary culture of mouse endometrial epithelium was investigated using the short circuit current (ISC) technique.
- 2Adrenaline stimulated a sustained increase in the ISC in a concentration-dependent manner. The adrenaline-induced ISC could be inhibited by pretreatment with diphenylamine 2,2'-dicarboxylic acid (DPC) or replacement of external Cl− and HCO3−, but not by amiloride or replacement of Na+ in apical solution.
- 3The concentration-dependent responses of the adrenaline-induced ISC to the CF channel blockers glibenclamide and DPC were examined and exhibited IC50 values of 380 and 960 μm, respectively.
- 4The effect of various adrenoceptor agonists on the ISC was examined. The order of potency appeared to be isoprenaline > adrenaline > noradrenaline, while no response was elicited by the α-adrenoceptor agonist methoxamine, indicating a predominant involvement of β-adrenoceptors.
- 5The β-adrenoceptor antagonist propranolol was found to be much more effective than the α-adrenoceptor antagonist phentolamine in inhibiting the ISC responses induced by all adrenoceptor agonists examined.
- 6The effect of adrenaline on the ISC was mimicked by an adenylate cyclase activator, forskolin, but suppressed by the adenylate cyclase inhibitor MDL 12,330A, indicating the involvement of cAMP.
- 7Our results demonstrate that anion secretion by the mouse endometrial epithelium is regulated by β-adrenoceptors and involves a cAMP-dependent mechanism.