Lipid-soluble fraction of Shakuyaku-kanzo-to inhibits myometrial contraction in pregnant women.

AIM: Shakuyaku-kanzo-to, a Kampo medicine composed equally of shakuyaku and kanzo, is an antispasmodic drug that can inhibit contraction of uterine smooth muscles in pregnant women and rats. We aimed to test the inhibitory effects of water- and lipid-soluble extracts of shakuyaku-kanzo-to, shakuyaku, and kanzo in order to identify the fraction responsible for inhibiting uterine smooth muscle contraction in pregnancy. MATERIAL AND METHODS: Myometrial tissues were obtained from pregnant women and rats. The water- and lipid-soluble fractions of shakuyaku-kanzo-to, shakuyaku, and kanzo were obtained using the method of Bligh and Dyer. Lipid-soluble fractions were also partially purified using thin-layer chromatography (TLC) with a chloroform : methanol : water (65:25:4 by volume) solvent system to yield four TLC fractions. The effect of each fraction on oxytocin-induced myometrial contraction was examined in vitro. RESULTS: Lipid-soluble fractions obtained from shakuyaku-kanzo-to and kanzo inhibited myometrial contraction; water-soluble fractions had no effect. Of the four TLC fractions, the inhibitory effect was greatest with TLC fraction 1 (0.75 < Rf value ≤ 1.0). Neither the water-soluble nor the lipid-soluble fraction from shakuyaku inhibited myometrial contraction. CONCLUSIONS: These results suggest that lipid-soluble substances with low polarity derived from kanzo are responsible for the inhibitory effect of shakuyaku-kanzo-to on myometrial contraction.

Effect of cigarette smoking on mRNA and protein levels of oxytocin receptor and on contractile sensitivity of uterine myometrium to oxytocin in pregnant women.

OBJECTIVES: Although smoking is the most important modifiable risk factor associated with preterm delivery, the underlying mechanism by which smoking stimulates premature uterine contractions is still poorly understood. In the present study, we investigated whether cigarette smoking affects the contractile sensitivity of uterine myometrium to oxytocin in pregnant women. STUDY DESIGN: Cigarette smoking habits of pregnant women were evaluated by direct interviews and by measuring exhaled carbon monoxide (CO). We isolated myometrial strips from pregnant smokers and non-smokers and evaluated uterine contractile sensitivity to oxytocin. Gene expression levels of oxytocin receptors (OTR) were compared between myometrial strips obtained from smokers and non-smokers by real-time PCR. OTR protein levels in the myometrium were evaluated by Western blotting. RESULTS: The reported number of cigarettes smoked per day by the interviewee significantly correlated with the concentration of exhaled CO. Oxytocin sensitivity increased significantly in smokers (n=6) compared with non-smokers (n=11). Real-time PCR analysis did not reveal any significant difference in OTR mRNA expression between smokers and non-smokers. Western blotting revealed that OTR level was significantly increased in smokers compared with non-smokers. Both number of cigarettes smoked per day and the concentration of exhaled CO correlated with oxytocin sensitivity. CONCLUSION: Our findings suggest that smoking increases oxytocin sensitivity of pregnant myometrium by increasing OTR levels even though OTR mRNA expression remains unaltered, thereby increasing the risk of preterm delivery in women who smoke during pregnancy. The sensitivity is dependent on number of cigarettes smoked per day.

Two-step inhibitory effect of kanzo on oxytocin-induced and prostaglandin F2α-induced uterine myometrial contractions.

We previously reported that shakuyaku-kanzo-to, a kampo medicine consisting of shakuyaku and kanzo, has an inhibitory effect on myometrial contractions in pregnant women. In this study, we evaluated the effects of kanzo, glycyrrhizin (a major component of kanzo), glycyrrhetinic acid (GA; a major metabolite of glycyrrhizin), shakuyaku, and paeoniflorin (a major component of shakuyaku) on agonist-induced contractions of the uterus of pregnant humans and rats. We prepared myometrial strips from the uterus of pregnant humans and rats and induced contractions with oxytocin (50 µU/mL) or prostaglandin F2α (PGF2α) (10(-7) or 10(-6) M). Kanzo (250 µg/mL) and GA (5 × 10(-6) M) inhibited the oxytocin-induced and PGF2α-induced contractions in pregnant human and rat myometrium, but shakuyaku (250 µg/mL), paeoniflorin (10(-5) M), and glycyrrhizin (10(-5) M) did not inhibit contractions in either. Interestingly, kanzo and GA showed an inhibitory effect after temporarily enhancing the PGF2α-induced contractions in the rat myometrium, but not in the human myometrium. These results suggest that kanzo has at least a two-step inhibitory effect on the myometrial contractions that originate from the kanzo itself and a metabolite of glycyrrhizin in kanzo. Furthermore, kanzo was found to be safe for inhibiting PGF2α-induced contractions in humans because it did not temporarily enhance PGF2α-induced contractions.

Effects of ovarian hormone treatment on the gene expression of muscarinic acetylcholine receptors in the ovariectomized rat myometrium.

We investigate the effects of ovarian hormone on the gene expression of muscarinic acetylcholine receptors (M1-M5) in the myometrium using real-time PCR and evaluate the relationships between their expression and that of ovarian hormone receptors (ERα, ERß, and PgR). Wistar rats were sham operated (SO) or ovariectomized (OVX) and treated with vehicle, estradiol (E2), progesterone (P4), or both E2 and P4 for 2 days beginning on postoperative day 33. M1 and M4 mRNA expressions were not detected in the myometrium. M2 mRNA expression did not change significantly in the OVX and OVX+P4 groups compared to the SO group, but increased significantly in the OVX+E2 group and was normalized in the OVX+E2P4 group. M3 mRNA expression increased significantly in the OVX and OVX+P4 groups compared to the SO group, but was normalized in the OVX+E2 and OVX+E2P4 groups. M5 mRNA expression did not change significantly in all experimental groups. ERα mRNA expression increased significantly in the OVX, OVX+E2, and OVX+P4 groups compared to the SO group, but was normalized in the OVX+E2P4 group. The changes in ERß mRNA expression were similar to those of M3 mRNA expression in all experimental groups. In contrast, the changes in PgR mRNA expression did not correspond with that of M2, M3, or M5 mRNA expression in any of the experimental groups. Additionally, we evaluated the relationship between the expression of muscarinic acetylcholine receptors and ovarian hormone receptors in estrus cycle. M2 mRNA expression increased significantly in diestus and metaestrus compared in proestrus and estrus. M3 mRNA expression increased significantly in only diestrus compared in the other stages. In contrast, M5 mRNA expression did not change in estrus cycle. The changes in ERα mRNA expression appeared to be similar to those of M2 in estrus cycle, but no significant difference was found. The changes in ERß mRNA expression were similar to those of M3 mRNA expression. The change in PgR mRNA expression increased significantly in diestrus compared in metaestrus, but did not correspond with that of M2, M3, or M5 mRNA expression in estrus cycle. When acetylcholine sensitivity in the myometrium was compared between diestrus and estrus, the sensitivity is significantly lower in estrus than in diestrus. These results suggest that ovarian hormones influence the expression of M2 and M3 in the myometrium by regulating the expression of hormone receptors. E2 may upregulate M2 via ERα, but P4 may downregulate M2 by inhibiting ERα via PgR. E2 may downregulate M3 by inhibiting ERß, but P4 may not regulate the expression of M3 and ERß. M5 may be a constitutive muscarinic receptor in the myometrium because neither E2 nor P4 influence the expression of M5. The combination of E2 and P4 may contribute the reproduction by quieting down the acetylcholine-induced myometrial contraction.

Three-cycle fentanyl patch system contributes to stable control of plasma fentanyl concentration in gynecologic cancer pain patients.

OBJECTIVE: Pain affects many cancer patients in advancing stages, lowering the level of their quality of life. Morphine has long been the "gold standard" for the treatment of cancer pain; however, its side effects, particularly sedation and cognitive impairment at high doses, have encouraged the use of "opioid rotation". The transdermal fentanyl patch has advantages over oral morphine, with reduced side effects and increased convenience in practical usage. The side effects were reduced in patients who changed to the fentanyl patch, but rescue analgesia was often needed because of the decrease of fentanyl release from the patch, especially on patch replacement day. To maintain a stable fentanyl plasma level before patch replacement, we have established a three-cycle fentanyl patch system and reported that it provided appropriate pain control. The objective of this study was to investigate the individual variability of plasma fentanyl concentration in a three-cycle fentanyl patch system. CASE REPORT: The gynecologic cancer patients were treated using the three-cycle fentanyl patch system. Blood samples were taken from the patients and plasma fentanyl concentration was analyzed. A stable plasma fentanyl level was observed, and good pain control was achieved in each patient using the three-cycle fentanyl patch system. A stable plasma fentanyl level was maintained the day before the conventional patch replacement day. DISCUSSION: The three-cycle fentanyl patch system provided a stable plasma fentanyl concentration and excellent pain relief and should be considered for pain control in cancer patients.

Three-cycle fentanyl patch system significantly improves pain control in gynecologic cancer.

Pain affects many cancer patients, and in advanced stages of the disease it can significantly affect the quality of their lives. Morphine has long been the 'gold standard' for the treatment of cancer pain. However, its side-effects, particularly sedation and cognitive impairment at high doses, have encouraged the use of 'opioid rotation'. The transdermal fentanyl patch has advantages over oral morphine, with reduced side-effects and increased convenience in practical usage. The side-effects were reduced in patients who changed to the fentanyl patch, but rescue analgesia was often needed because of the decrease of fentanyl release from the patch, especially on the patch replacement day. We have developed a three-cycle fentanyl patch system that provided an appropriate pain control, and this system should be considered for pain relief in cancer patients.