This study was performed to determine the action mode of oxytocin antagonist. In Study 1, the duration of in vivo action of oxytocin antagonist I (AI) was examined. After infusing AI, oxytocin was given and repeated every hour for 5 hr. Uterine activities were monitored with a polygraph. Study 2 determined the effect of AI on uterine oxytocin receptor number (Rn) and binding affinity (Kd). AI treated rats were sacrificed at 0.5 and 4 hr later for receptor assay. In Study 1, the uterine contractile response to oxytocin was significantly inhibited (p>0.05) compared to controls at five min, 1 and 2 hr after injection of AI. No differences in response were detected compared to controls (p>0.05) at later hours. In Study 2, no differences (p>0.05) between the AI and control animals in either oxytocin receptor number or binding affinity was found. These data suggest that the major mode of AI action is via competitive inhibition at the uterine oxytocin receptor and not by altering receptor number or binding affinity. AI is suggested to have the potential of being a potent and specific tocolytic agent for prevention of preterm labor in human.
Animal ; Female ; Oxytocin/pharmacology ; Oxytocin/metabolism ; Oxytocin/antagonists & inhibitors* ; Rats ; Receptors, Oxytocin/metabolism ; Uterus/physiology ; Uterus/drug effects*

This study was performed to determine the action mode of oxytocin antagonist. In Study 1, the duration of in vivo action of oxytocin antagonist I (AI) was examined. After infusing AI, oxytocin was given and repeated every hour for 5 hr. Uterine activities were monitored with a polygraph. Study 2 determined the effect of AI on uterine oxytocin receptor number (Rn) and binding affinity (Kd). AI treated rats were sacrificed at 0.5 and 4 hr later for receptor assay. In Study 1, the uterine contractile response to oxytocin was significantly inhibited (p>0.05) compared to controls at five min, 1 and 2 hr after injection of AI. No differences in response were detected compared to controls (p>0.05) at later hours. In Study 2, no differences (p>0.05) between the AI and control animals in either oxytocin receptor number or binding affinity was found. These data suggest that the major mode of AI action is via competitive inhibition at the uterine oxytocin receptor and not by altering receptor number or binding affinity. AI is suggested to have the potential of being a potent and specific tocolytic agent for prevention of preterm labor in human.
Animal ; Female ; Oxytocin/pharmacology ; Oxytocin/metabolism ; Oxytocin/antagonists & inhibitors* ; Rats ; Receptors, Oxytocin/metabolism ; Uterus/physiology ; Uterus/drug effects*

OBJECTIVETo analyze the level of the oxytocin (OT) and the expression of oxytocin receptor (OTR) in males with idiopathic infertility.

METHODSSixty-five infertile males aged 20 -45 years were divided according to their semen parameters into an idiopathic oligozoospermia group (OG, n = 20), an idiopathic asthenozoospermia group (AG, n = 25), and an idiopathic oligoasthenozoospermia group (OAG, n = 20). Another twenty 20-45 years old healthy male volunteers with a natural childbearing history were included in the control group (CG). All the subjects were detected for the contents of luteinizing hormone (LH), follicle stimulating hormone (FSH) , testosterone (T) and OT, and analyzed for the expression of OTR by sequencing the functional region of the OTR promoter (OTRP), OTR-mRNA, and OTR-COOH terminus. The gene sequences were compared using DNASTAR-MegAlign, Western blot values changed into enumeration data, and all the data analyzed by one-way ANOVA and Dunnette's multiple range t-test.

RESULTSA significantly lower content of OT was observed in CG ( [79.30 +/- 3.83] pg/ml) than in OG ([118.53 +/- 7.69] pg/ml, AG ([108.81 +/- 5.66] pg/ml) and OAG ([103.71 +/- 4.54] pg/ml) (F(0.05/2[2,82]) = 8.29, P < 0.01). The content of LH was significantly lower in AG ([4.26 +/- 0.31] IU/L) and OAG ([4.55 +/- 0.40] IU/L) than in OG ([6.77 +/- 0.57] IU/L) and CG ([7.19 +/- 0.50] IU/L) (F(0.05/2 [2,82]) = 11.64, P < 0.01), and so was the content of FSH in AG ( [5.02 + 0.39] IU/L) than in CG ([8.91 +/- 0.91] IU/L), OG ([11.86 +/- 1.76] IU/L) and OAG ([8.82 +/- 1.03] IU/L) (F(0.05/[2,82]) = 7.22, P < 0.01). There were no significant differences in the T content among the four groups (F(0.05/2[2,82] = 0.42, P = 0.739). No evident gene mutation was found in OTRP and OTR-mRNA gene sequencing. Human OTRs in the lymphocytes were monomers and oligomers, mostly tetramers and hexamers. There were obviously more monomers in AG (0.41 +/- 0.03) and OAG (0.13 +/- 0.01) than in OG (0.05 +/- 0.004) and CG (0.05 +/- 0.003) (F(0.05/2[2,82]) = 115.50, P < 0.01), while the number of oligomers was markedly decreased in 20% of the cases in AG.

CONCLUSIONSignificant differences in the content of OT and expression of OTR between fertile and infertile men suggested an association of OT with male infertility. The decreased expression of OTR oligomers and increased expression of monomers may be related to idiopathic asthenozoospermia, which has provided a new insight into the pathogenesis and treatment of male infertility.

Adult ; Case-Control Studies ; Humans ; Infertility, Male ; metabolism ; pathology ; Male ; Middle Aged ; Neuropeptides ; metabolism ; Oxytocin ; metabolism ; Receptors, Oxytocin ; metabolism ; Young Adult

OBJECTIVETo probe the mechanism of acupuncture in treatment of dysmenorrhea.

METHODSAdult mice with no pregnancy were randomly divided into a normal group, a model group, an acupuncture group and a medication group. The model group, the acupuncture group and the medication group were modeled by Diethylstilbestrol and Ocytocin. For the acupuncture group, at the 7th day of modeling, acupuncture was given at "Sanyinjiao" (SP 6), "Diji" (SP 8), once a day, for 5 days; and at the 7th day of modeling, Yimucao Gao 0.6 mg/g was given intragastrically to the medication group for 5 days. The stretching latent period and the number of stretching within 30 min were observed, and mRNA levels of ocytocin receptor (OctR) and vasopressin receptor (VasR) in the uterus tissue were detected with RT-PCR method.

RESULTSCompared with the model group, the stretching latent period extended (P < 0.05) and the number of stretching within 30 min significantly decreased (P < 0.05); and there were significant differences in the mRNA levels of ocytocin receptor and vasopressin receptor in the uterus tissue in the model group as compared with those in other 3 groups (P < 0.05, P < 0.01).

CONCLUSIONAcupuncture can improve the dysmenorrheal symptom to a certain extent, and the mechanism is possibly related to regulative effects of acupuncture on hormones-mediating receptors in mice.

Acupuncture Therapy ; Animals ; Dysmenorrhea ; metabolism ; therapy ; Female ; Mice ; RNA, Messenger ; analysis ; Receptors, Oxytocin ; genetics ; Receptors, Vasopressin ; genetics

Radioiodinated oxytocin prepared by the lactoperoxidase method exhibited a substantial biologic activity in uterotonic assay of the rat uterus. 125I-oxytocin was bound to the uterine membrane particulate fraction, but the unlabelled oxytocin did not inhibit the binding of 125I oxytocin to the membrane fraction of rat uterus. Cold iodinated oxytocin, however, inhibited the 125I-oxytocin binding to the membrane fraction of rat uterus in proportion to its concentration. These results suggest that 125I-oxytocin is not a suitable radioligand for oxytocin receptor binding study.
Animal ; Binding Sites ; Cell Membrane/metabolism ; Female ; Iodine Radioisotopes/metabolism* ; Oxytocin/metabolism* ; Radioligand Assay ; Rats ; Receptors, Cell Surface/analysis* ; Uterus/metabolism*

OBJECTIVETo observe the influence of silencing Connexin43 (Cx43) expression of partial acupoints on acupuncture effect, so as to probe into the mechanism of acupuncture treatment for primary dysmenorrhea.

METHODSThe primary dysmenorrheal rat model made by oxytocin and RNA interference (RNAi) technology was used to silence the expression of Cx43 in acupoints. Fifty SD female rats were divided into five groups, a normal group (N), a model group (M), an acupuncture group (A), an acupuncture plus interference group (A+I), an acupuncture plus interference control group (A+IC). RT-PCR method was used to observe the oxytocin receptor (OTR) and vasopressin receptor (VPR) mRNA expressions in the uterus in each group. Plasma prostaglandin E2 (PGE2) and PGF2alpha levels were detected by radioimmunoassay and ELISA, respectively.

RESULTS(1) The times of writhing body (9.43 +/- 3.87 and 10.28 +/- 4.23) were significantly lower and the latency period of writhing body (12.43 +/- 3.46, 11.00 +/- 3.65) were longer in the group A and the group A+IC as compared with (15.43 +/- 5.13, 17.00 +/- 3.87) and (7.57 +/- 1.99, 8.43 +/- 2.57) in the group M and group A+I (P < 0.05), respectively. (2) The levels of Cx43 mR NA level and protein expression of acupoint in the group A+I were significantly lower than those of the group N (P < 0.05). (3) OTR and VPR mRNA in the uterus in the group A and the group A+IC were significantly lower than those in the group M and the group A+I (P < 0.05), with no significant difference between the group M and the group A+I (P > 0.05). (4) As compared with the group M, PGE2 level increased and PGF2alpha level decreased in the group A and the group A+IC (P < 0.05).

CONCLUSIONSilencing Cx43 expression of partial acupoint can inhibit effectively the effect of acupuncture through decreasing OTR and VPR in endometrium of the dysmenorrheal rat and adjusting the prostaglandins (PGs) synthesis system, which possibly is one of the mechanisms of acupuncture for treatment of primary dysmenorrhea.

Acupuncture Points ; Acupuncture Therapy ; Animals ; Connexin 43 ; genetics ; metabolism ; Dinoprost ; blood ; Dinoprostone ; blood ; Dysmenorrhea ; genetics ; metabolism ; therapy ; Female ; Gene Expression ; Humans ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Oxytocin ; genetics ; metabolism ; Receptors, Vasopressin ; genetics ; metabolism ; Uterus ; metabolism

Chromosome Aberrations ; Diagnosis, Differential ; Endometrial Neoplasms ; genetics ; metabolism ; pathology ; Endometrial Stromal Tumors ; genetics ; metabolism ; pathology ; Female ; Histone Deacetylases ; metabolism ; Humans ; Immunohistochemistry ; Neprilysin ; metabolism ; Receptors, Oxytocin ; metabolism ; Repressor Proteins ; metabolism ; Sarcoma, Endometrial Stromal ; genetics ; metabolism ; pathology ; Uterine Neoplasms ; metabolism ; pathology