TY - JOUR
T1 - Extracellular Ca2+ entry and mobilization of inositol trisphosphate-dependent Ca2+ stores modulate histamine and electrical field stimulation induced contractions of the guinea-pig prostate
AU - Lam, Michelle
AU - Kerr, Karen
AU - Ventura, Sabatino
AU - Exintaris, Betty
PY - 2011
Y1 - 2011
N2 - This investigation aimed to examine the source of Ca(2+) mobilization that leads to the contractile response to either exogenously added histamine (1I?M-1mM) or electrical field stimulation (10Hz, 0.5ms, 60V). Removal of extracellular Ca(2+) by removal of Ca(2+) from the bathing medium reduced histamine (1mM) induced responses by 34 and responses induced by electrical field stimulation by 94 . Similarly, blockade of L-type Ca(2+) channels by nifedipine (1I?M) reduced histamine (1mM) induced responses by 43 and responses induced by electrical field stimulation by 77 . Application of cyclopiazonic acid (CPA) (10I?M) to inhibit Ca(2+) reuptake to the sarcoplasmic reticulum enhanced both histamine-induced and electrical field stimulation induced responses to a small degree, while the addition of the inosotol triphosphate (IP(3)) receptor antagonist, 2-aminophenoxyethane borane (2-APB) (100I?M) inhibited histamine induced responses by 70 and electrical field stimulation induced responses by 57 . Ryanodine (1I?M) did not affect contractile responses to either histamine or electrical field stimulation, either in the absence or presence of 2-APB (100I?M). During both histamine and electrical field stimulation induced contractions, prostate smooth muscle generates IP(3) receptor mediated Ca(2+) release in conjunction with Ca(2+) entry from the extracellular environment. Ryanodine receptors on the other hand, appear not to play a role in this physiological mechanism.
AB - This investigation aimed to examine the source of Ca(2+) mobilization that leads to the contractile response to either exogenously added histamine (1I?M-1mM) or electrical field stimulation (10Hz, 0.5ms, 60V). Removal of extracellular Ca(2+) by removal of Ca(2+) from the bathing medium reduced histamine (1mM) induced responses by 34 and responses induced by electrical field stimulation by 94 . Similarly, blockade of L-type Ca(2+) channels by nifedipine (1I?M) reduced histamine (1mM) induced responses by 43 and responses induced by electrical field stimulation by 77 . Application of cyclopiazonic acid (CPA) (10I?M) to inhibit Ca(2+) reuptake to the sarcoplasmic reticulum enhanced both histamine-induced and electrical field stimulation induced responses to a small degree, while the addition of the inosotol triphosphate (IP(3)) receptor antagonist, 2-aminophenoxyethane borane (2-APB) (100I?M) inhibited histamine induced responses by 70 and electrical field stimulation induced responses by 57 . Ryanodine (1I?M) did not affect contractile responses to either histamine or electrical field stimulation, either in the absence or presence of 2-APB (100I?M). During both histamine and electrical field stimulation induced contractions, prostate smooth muscle generates IP(3) receptor mediated Ca(2+) release in conjunction with Ca(2+) entry from the extracellular environment. Ryanodine receptors on the other hand, appear not to play a role in this physiological mechanism.
U2 - 10.1016/j.phrs.2011.04.009
DO - 10.1016/j.phrs.2011.04.009
M3 - Article
SN - 1043-6618
VL - 64
SP - 235
EP - 241
JO - Pharmacological Research
JF - Pharmacological Research
IS - 3
ER -