Alamin 996 is a mixture of mineral contained in the milk whey and has been reported to be effective against dysmenorrhea This study aimed to investigate the effect of Alamin 996 on the prostaglandin F
2α (PGF
2α)-induced contraction in the isolated rat uterus. PGF
2α induced the rhythmic contraction. The frequency of this contraction was concentration-dependently inhibited by Alamin 996, but the contractile force was not significantly affected. To clarify this inhibitory mechanism by Alamin996, the effects of BAY K 8644, Ca
2+ channel agonist, and dantrolene, inhibitor of the calcium-induced calcium release from the endoplasmic reticulum, were tested. The inhibitory effect on the rhythmic contractile frequency by Alamin 996 was significantly and concentration-dependently attenuated by the addition of BAY K 8644, suggesting Alamin 996 did not affect on the smooth muscle contractile function. Even under the pretreatment with dantrolene, Alamin 996 concentration-dependently inhibited the rhythmic contractile frequency, suggesting no involvement of ryanodine receptor on the effect of Alamin 996. Alamin 996 was found to inhibit phospholipase C activity by in vitro study. The effect of Mg
2+ containing Alamin 996 was tested. Mg
2+ significantly and concentration-dependently inhibited the frequency of PGF
2α-induced rhythmic contraction. Moreover, contractile force was also markedly inhibited, suggesting the difference of the inhibitory mechanism between Alamin 996 and Mg
2+ sulfate. These results show that Alamin 996 inhibits the PGF
2α-induced rhythmic contractile frequency without affecting the contractile force and that this inhibitory action mediated by inhibiting calcium release from the endoplasmic reticulum through phospholipase C may explain the utility of Alamin 996 against dysmenorrhea.
抄録全体を表示