ABSTRACT
Plasma pH can be altered during pregnancy and at labor. Membrane excitability of smooth muscle including uterine muscle is suppressed by the activation of K(+) channels. Because contractility of uterine muscle is regulated by extracellular pH and humoral factors, K(+) conductance could be connected to factors regulating uterine contractility during pregnancy. Here, we showed that TASK-2 inhibitors such as quinidine, lidocaine, and extracellular acidosis produced contraction in uterine circular muscle of mouse. Furthermore, contractility was significantly increased in pregnant uterine circular muscle than that of non-pregnant muscle. These patterns were not changed even in the presence of tetraetylammonium (TEA) and 4-aminopyridine (4-AP). Finally, TASK-2 inhibitors induced strong myometrial contraction even in the presence of L-methionine, a known inhibitor of stretchactivated channels in myometrium. When compared to non-pregnant myometrium, pregnant myometrium showed increased immunohistochemical expression of TASK-2. Therefore, TASK-2, seems to play a key role during regulation of myometrial contractility in the pregnancy and provides new insight into preventing preterm delivery.
ABSTRACT
BACKGROUND: Multifetal cervical pregnancy is very rare. We are reporting a case of a triplet cervical pregnancy that was treated with direct intraamniotic instillation of methotrexate. CASE: A young multiparous woman was diagnosed as having three gestational sacs in her uterine cervix with embryonic cardiac activity observed within one of the sacs. She became pregnant by natural ovulation and coitus. After initial failure with a single-dose intramuscular injection, the patient was successfully treated with an intra-amniotic methotrexate injection under the guidance of transvaginal ultrasonography. Her reproductive capability was preserved. CONCLUSION: Direct intraamniotic injection can be considered as treatment for multifetal cervical pregnancy.
