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17β‐Estradiol relaxes cholecystokinin (CCK) and KCl‐induced tension in female guinea pig gallbladder strips by inhibiting extracellular Ca 2+ entry
Author(s) -
Kline Loren,
Karpinski Edward
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1163.1
Subject(s) - chemistry , endocrinology , medicine , cholecystokinin , extracellular , bombesin , guinea pig , relaxation (psychology) , neuropeptide , biochemistry , receptor
17β‐estradiol (E2) induced a concentration‐dependent relaxation of CCK‐ or KCl‐induced tension. When the response to E2 between strips from young guinea pigs and strips from those in late pregnancy were compared there was no significant difference in the response to 50 or 100 μM E2; but, 10μM caused a significant (p<0.05, 19.3±5.4 vs. 25.9±2.7%, n=7) increase in the amount of relaxation in strips from pregnant guinea pigs. PKA inhibitor 14–22 amide myristolated had no significant effect on the E2‐induced relaxation. Treatment with 2‐APB, an inhibitor of IP 3 induced Ca 2+ release, produced a significant (p<0.01) increase in the amount of E2‐induced relaxation when either CCK or KCl were used. Neither KT5823, a PKG inhibitor, nor L‐NMMA, a NO synthase inhibitor, had a significant effect on the E2‐induced relaxation. Bisindolymaleimide IV and chelerythrine Cl − , PKC blockers, were used in combination with no significant effect on the amount of CCK‐induced tension, but significantly (p<0.01) increased the amount of E2‐induced relaxation. When E2 was added to the chambers 3 min prior to either CCK or KCl, a significant (p<0.001) decrease in the amount of tension was observed (CCK, 0.78±0.08 vs. 0.36±0.03g, n=5; KCl, 1.09±0.06 vs. 0.20±0.02g, n=6). The inhibition of extracellular Ca 2+ entry mediated E2‐induced relaxation of CCK‐ and KCl‐induced tension in female guinea pig gallbladder strips.