Corticotropin-releasing hormone acts on CRH-R1 to inhibit the spontaneous contractility of non-labouring human myometrium at term.

AIMS: Corticotropin-releasing hormone (CRH) has been implicated in the mechanisms controlling human parturition. The aims of the present study were to explore effects of CRH on contractility of human term myometrium and compare these effects in labouring and non-labouring myometrial strips. MAIN METHODS: The cumulative effects of CRH (10(-10) to 10(-7) mol/l) on the spontaneous contractility of labouring and non-labouring myometrial samples were evaluated using isometric tension recordings. KEY FINDINGS: CRH exhibited a concentration-dependent relaxant effect on spontaneous contractions in non-labouring term myometrium. This effect was mediated principally via a reduction in the amplitude rather than any changes in the frequency of contractions. The CRH-induced inhibitory effect on contractility could be blocked by pre-treatment with a CRH-R1 antagonist antalarmin, but not by pre-treatment with the CRH-R2 antagonist astressin 2B. CRH had no effect on spontaneous contractions in the labouring myometrium, as no change in either the amplitude or the frequency was observed. SIGNIFICANCE: Our findings indicate that CRH acts on CRH-R1 to inhibit spontaneous contractions in term myometrium from women who were not undergoing labour, but not those who were undergoing labour, supporting the hypothesis that CRH exerts dual effect on myometrium during pregnancy.

[Changes and significance of orphanin and serotonin in patients with postpartum depression].

OBJECTIVE: To study the changes of orphanin (OFQ) and serotonin (5-HT) in the patients with postpartum depression (PPD). METHODS: Twenty one patients with postpartum depression (PPD group) and 25 healthy lying-in women (control group) were studied. The concentrations of plasma OFQ were measured by radioimmunoassay. The levels of 5-HT were measured with high-pressure liquid chromatography with electrochemical detector. RESULTS: (1) The levels of plasma OFQ in PPD group were (28.5 +/- 5.8) ng/L, in control group, the levels of OFQ was (10.4 +/- 3.7) ng/L, the levels of OFQ in PPD group were significantly higher than that in the control group (P < 0.01). (2) The levels of plasma 5-HT in PPD group and control group were (1.0 +/- 0.3) micro mol/L and (1.4 +/- 0.4) micro mol/L respectively, the levels of 5-HT in PPD group decreased significantly (P < 0.05). (3) In the PPD group, there was a significant negative correlation between the OFQ and 5-HT level (P < 0.05). CONCLUSION: The PPD was associated with OFQ and 5-HT, the changes of OFQ levels may play an important role in the pathogenesis of the PPD.

[Changes of hypothalamus and peripheral orphanin in fetal rats with intrauterine ischemia and hypoxia].

OBJECTIVE: To evaluate the role of orphanin in the perinatal ischemia-hypoxia. METHODS: The concentration of hypothalamus and peripheral orphanin were measured by radioimmunoassay. Animal model of perinatal ischemia-hypoxia was set up by ligating uterine vessels. All the rats were delivered by cesarean section and scored according to respiration, heart beat, skin color, muscle tone and reflex after delivery. RESULTS: (1) The levels of orphanin in hypothalamus and peripheral blood in group B were (114 +/- 21) pg/g and (58 +/- 11) ng/L respectively. In group A, the were (71 +/- 14) pg/g and (31 +/- 7) ng/L respectively, the levels of orphanin in group B increased significantly when compared with the group A (P < 0.05). In control group, the levels of orphanin were (48 +/- 9) pg/g and (19 +/- 4) ng/L. The levels of orphanin in group A and B were significantly higher than those in the control group (P < 0.01, P < 0.05). (2) The Apgar scores in groups A and B were significantly decreased than that in control group (P < 0.01). The group A pups had significantly better scores than the group B (P < 0.05). CONCLUSION: The perinatal ischemia and hypoxia was associated with orphanin, the changes of orphanin levels may play an important role in the pathophysiological changes in perinatal ischemia and hypoxia.