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| 2. |
- Batra, Satish, et al.
(författare)
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Important differences in nitric oxide synthase activity and predominant isoform in reproductive tissues from human and rat.
- 2003
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Ingår i: Reproductive Biology and Endocrinology. - : Springer Science and Business Media LLC. - 1477-7827. ; , s. 10-10
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Tidskriftsartikel (refereegranskat)abstract
- For the extrapolation of data obtained from experimental animals to the human situation, it is important to know the similarities and differences between human and animal species. Some important characteristics of nitric oxide synthase (NOS) in myometrium and vagina from human and rat were compared. NOS-activity was measured by the formation of 14C-citrulline from 14C-arginine and the expression of NOS isoforms was examined by Western blotting. NOS activity in human uterus and vagina was significantly lower than in the tissues from rat. In contrast to the rat where NOS activity was predominantly found in the cytosolic fractions, NOS activity in particulate and cytosolic fractions from both human myometrium and vagina was similar. Data from Western blots confirmed that eNOS and nNOS isoforms were concentrated in the particulate and cytosolic fractions, respectively. Estrogen treatment of rats resulted in a down regulation of uterine cytosolic NOS activity. A down regulation of NOS in the cytosolic fraction was also seen in the human pregnant myometrium as compared with the nonpregnant myometrium. The vaginal NOS activity was considerably higher than the uterus in both species. In spite of some clear-cut qualitative and other differences between human and rat tissues, there are some interesting similarities. Downregulation in pregnancy of human uterine NOS is probably due to, at least in part, the influence of estrogen and progesterone.
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| 3. |
- Cluff, AH, et al.
(författare)
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Prolonged labour associated with lower expression of syndecan 3 and connexin 43 in human uterine tissue
- 2006
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Ingår i: Reproductive Biology and Endocrinology. - : Springer Science and Business Media LLC. - 1477-7827. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Prolonged labour is associated with greater morbidity and mortality for mother and child. Connexin 43 is a major myometrial gap junction protein found in human myometrium. Syndecan 3 seems to prevail in the human uterus among heparan sulphate proteoglycans, showing the most significant increase during labour. The aims of the present study were to investigate syndecan 3 and connexin 43 mRNA expressions and protein distributions in human uterine tissue during normal and prolonged labour. Methods: Uterine isthmic biopsies were collected from non-pregnant (n = 7), term pregnant women not in labour (n = 14), in normal labour (n = 7) and in prolonged labour (n = 7). mRNA levels of syndecan 3 and connexin 43 were determined by real time RT-PCR. The localization and expression were demonstrated by immunohistochemistry and confocal microscopy. Results: In women with prolonged labour, the mRNA expressions of syndecan 3 and Connexin 43 were considerably lower than the expression level at normal labour (p < 0.05). In term-pregnant tissue, the expression of syndecan 3 and connexin 43 did not differ significantly compared to nonpregnant and normal labour. The immunoreactivity of syndecan 3 was strong at normal labour, in contrast to prolonged labour, where both a weaker expression and an irregular distribution were detected. The immunoreactivity of connexin 43 increased until term and further stronger staining occurred at normal labour. At prolonged labour, the immunoreactivity was weaker and more unevenly distributed. At labour, a co-localization of syndecan 3 and connexin 43 could be demonstrated in the smooth muscle by confocal microscopy. Conclusion: The high expression of syndecan 3 and connexin 43 and their co-localization to the smooth muscle bundles during normal labour, together with the significant reduction in prolonged labour, may indicate a role for these proteins in the co-ordination of myometrial contractility.
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| 4. |
- Lundwall, Åke, et al.
(författare)
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Rapidly evolving marmoset MSMB genes are differently expressed in the male genital tract.
- 2009
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Ingår i: Reproductive Biology and Endocrinology. - : Springer Science and Business Media LLC. - 1477-7827. ; 7:Sep 9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Beta-microseminoprotein, an abundant component in prostatic fluid, is encoded by the potential tumor suppressor gene MSMB. Some New World monkeys carry several copies of this gene, in contrast to most mammals, including humans, which have one only. Here we have investigated the background for the species difference by analyzing the chromosomal organization and expression of MSMB in the common marmoset (Callithrix jacchus). METHODS: Genes were identified in the Callithrix jacchus genome database using bioinformatics and transcripts were analyzed by RT-PCR and quantified by real time PCR in the presence of SYBR green. RESULTS: The common marmoset has five MSMB: one processed pseudogene and four functional genes. The latter encompass homologous genomic regions of 32-35 kb, containing the genes of 12-14 kb and conserved upstream and downstream regions of 14-19 kb and 3-4 kb. One gene, MSMB1, occupies the same position on the chromosome as the single human gene. On the same chromosome, but several Mb away, is another MSMB locus situated with MSMB2, MSMB3 and MSMB4 arranged in tandem. Measurements of transcripts demonstrated that all functional genes are expressed in the male genital tract, generating very high transcript levels in the prostate. The transcript levels in seminal vesicles and testis are two and four orders of magnitude lower. A single gene, MSMB3, accounts for more than 90% of MSMB transcripts in both the prostate and the seminal vesicles, whereas in the testis around half of the transcripts originate from MSMB2. These genes display rapid evolution with a skewed distribution of mutated nucleotides; in MSMB2 they affect nucleotides encoding the N-terminal Greek key domain, whereas in MSMB3 it is the C-terminal MSMB-unique domain that is affected. CONCLUSION: Callitrichide monkeys have four functional MSMB that are all expressed in the male genital tract, but the product from one gene, MSMB3, will predominate in seminal plasma. This gene and MSMB2, the predominating testicular gene, have accumulated mutations that affect different parts of the translation products, suggesting an ongoing molecular specialization that presumably yields functional differences in accessory sex glands and testis.
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| 5. |
- Modzelewska, Beata, et al.
(författare)
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Apamin inhibits NO-induced relaxation of the spontaneous contractile activity of the myometrium from non-pregnant women
- 2003
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Ingår i: Reproductive Biology and Endocrinology. - : Springer Science and Business Media LLC. - 1477-7827. ; 1:8
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Tidskriftsartikel (refereegranskat)abstract
- There is now considerable evidence for the involvement of K+ channels in nitric oxide (NO) induced relaxation of smooth muscles including the myometrium. In order to assess whether apamin-sensitive K+ channels play a role in NO - induced relaxation of the human uterus, we have studied the effect of specific blockers of these channels on the relaxation of myometrium from non-pregnant women. In vitro isometric contractions were recorded in uterine tissues from non-pregnant premenopausal women who had undergone hysterectomy. Apamin (10 nM) and scyllatoxin (10 nM) did not alter spontaneous myometrial contractions. However, 15-min pretreatment of the myometrium strips with apamin completely inhibited relaxation caused by diethylamine-nitric oxide (DEA/NO). The pretreatment with scyllatoxin significantly reduced (about 2.6 times) maximum relaxation of the strips induced by DEA/NO (p < 0.05). These results strongly suggest that, beside Ca2+ and voltage dependent charybdotoxin-sensitive (CTX-sensitive) K+ channels, apamin-sensitive K+ channels are also present in the human non-pregnant myometrium. These channels offer an additional target in the development of new tocolytic agents.
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| 6. |
- Tornblom, SA, et al.
(författare)
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MRNA expression and localization of bNOS, eNOS and iNOS in human cervix at preterm and term labour
- 2005
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Ingår i: Reproductive Biology and Endocrinology. - : Springer Science and Business Media LLC. - 1477-7827. ; 3:33
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Tidskriftsartikel (refereegranskat)abstract
- Background: Preterm birth is the primary cause of the neonatal mortality and morbidity. There will be no preterm birth without a cervical softening. Nitric oxide ( NO) is shown to be a mediator of term cervical ripening. The aim of this study was to investigate mRNA expression of the three isomers of NO synthases ( NOS) and to identify them by immunohistochemistry in the human cervix at preterm birth compared to term. Methods: The three isomers of NOS- inducible ( iNOS), endothelial ( eNOS) and neuronal ( bNOS) - were investigated in the human cervix. The expression of mRNA was determined using RealTime Multiplex RT- PCR. The localisation of synthases in the cervical tissue was analysed using immunohistochemistry. Cervical biopsies were obtained from 4 groups of women without clinical signs of infection: preterm ( PTL), term labour ( TL), preterm not in labour ( PTnotL) and term not in labour ( TnotL) patients. One- Way ANOVA, Kruskal- Wallis, Student t- test or Mann- Whitney test were applied as appropriate to determine statistically significant differences among the groups. Results: Patients in preterm labour had significantly ( p < 0.01) higher mRNA levels of all the three NOS isomers compared to those in term labour. Women not in labour, irrespective of gestational age, thus with unripe cervices, had significantly lower eNOS mRNA levels compared to those in labour ( p < 0.01). Immunoreactivity for all three NO synthases was observed in each examined sample in all groups. The bNOS staining was the most prominent. Conclusion: The mRNA levels were higher in the preterm labour group compared to the women at term labour. The significant increase of the eNOS mRNA expression, from the unripe to the favourable cervical state during labour, may indicate a role of eNOS and supports the role of NO in the cervical ripening process. All the three synthases were identified by immunohistochemistry in all the groups of study.
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| 7. |
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| 8. |
- Benedet Perea, Susana, 1972, et al.
(författare)
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Cloning of somatolactin alpha, beta forms and the somatolactin receptor in Atlantic salmon: Seasonal expression profile in pituitary and ovary of maturing female broodstock
- 2008
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Ingår i: Reproductive Biology and Endocrinology. - : Springer Science and Business Media LLC. - 1477-7827. ; 6:42
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Tidskriftsartikel (refereegranskat)abstract
- Background Somatolactin (Sl) is a fish specific adenohypophyseal peptide hormone related to growth hormone (Gh). Some species, including salmonids, possess two forms: Sl alpha and Sl beta. The somatolactin receptor (slr) is closely related to the growth hormone receptor (ghr). Sl has been ascribed many physiological functions, including a role in sexual maturation. In order to clarify the role of Sl in the sexual maturation of female Atlantic salmon (Salmo salar), the full length cDNAs of slr, Sl alpha and Sl beta were cloned and their expression was studied throughout a seasonal reproductive cycle using real-time quantitative PCR (RTqPCR). Methods Atlantic salmon Sl alpha, Sl beta and slr cDNAs were cloned using a PCR approach. Gene expression of Sl alpha, SL beta and slr was studied using RTqPCR over a 17 month period encompassing pre-vitellogenesis, vitellogenesis, ovulation and post ovulation in salmon females. Histological examination of ovarian samples allowed for the classification according to the degree of follicle maturation into oil drop, primary, secondary or tertiary yolk stage. Results The mature peptide sequences of Sl alpha, Sl beta and slr are highly similar to previously cloned salmonid forms and contained the typical motifs. Phylogenetic analysis of Atlantic salmon Sl alpha and Sl beta shows that these peptides group into the two Sl clades present in some fish species. The Atlantic salmon slr grouped with salmonid slr amongst so-called type I ghr. An increase in pituitary Sl alpha and Sl beta transcripts before and during spawning, with a decrease post-ovulation, and a constant expression level of ovarian slr were observed. There was also a transient increase in Sl alpha and Sl beta in May prior to transfer from seawater to fresh water and ensuing fasting. Conclusion The up-regulation of Sl alpha and Sl beta during vitellogenesis and spawning, with a subsequent decrease post-ovulation, supports a role for Sl during gonadal growth and spawning. Sl could also be involved in calcium/phosphate mobilization associated with vitellogenesis or have a role in energy homeostasis associated with lipolysis during fasting. The up-regulation of both Sl alpha and Sl beta prior to fasting and freshwater transfer, suggests a role for Sl linked to reproduction that may be independent of the maturation induced fasting.
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| 9. |
- Berg, A. Håkan, et al.
(författare)
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Biochemical characterization of the Arctic char (Salvelinus alpinus) ovarian progestin membrane receptor
- 2005
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Ingår i: Reproductive Biology and Endocrinology. - : Springer Science and Business Media LLC. - 1477-7827. ; 3, s. 64-
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Tidskriftsartikel (refereegranskat)abstract
- Membrane progestin receptors are involved in oocyte maturation in teleosts. However, the maturation-inducing steroid (MIS) does not appear to be conserved among species and several progestins may fulfill this function. So far, complete biochemical characterization has only been performed on a few species. In the present study we have characterized the membrane progestin receptor in Arctic char (Salvelinus alpinus) and show that the 17,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P) receptor also binds several xenobiotics, thus rendering oocyte maturation sensitive to environmental pollutants. We identified a single class of high affinity (Kd, 13.8 +/- 1.1 nM), low capacity (Bmax, 1.6 +/- 0.6 pmol/g ovary) binding sites by saturation and Scatchard analyses. Receptor binding displayed rapid association and dissociation kinetics typical of steroid membrane receptors, with t1/2 s of less than 1 minute. The 17,20beta-P binding also displayed tissue specificity with high, saturable, and specific 17,20beta-P binding detected in ovaries, heart and gills while no specific binding was observed in muscle, brain or liver. Changes in 17,20beta-P binding during oocyte maturation were consistent with its identity as the oocyte MIS membrane receptor. Incubation of fully-grown ovarian follicles with gonadotropin induced oocyte maturation, which was accompanied by a five-fold increase in 17,20beta-P receptor binding. In addition, competition studies with a variety of steroids revealed that receptor binding is highly specific for 17,20beta-P, the likely maturation-inducing steroid (MIS) in Arctic char. The relative-binding affinities of all the other progestogens and steroids tested were less than 5% of that of 17,20beta-P for the receptor. Several ortho, para derivatives of DDT also showed weak binding affinity for the 17,20beta-P receptor supporting the hypothesis that xenobiotics may bind steroid receptors on the oocyte's surface and might thereby interfere with oocyte growth and maturation.
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| 10. |
- Berg, Håkan, et al.
(författare)
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17beta-estradiol induced vitellogenesis is inhibited by cortisol at the post-transcriptional level in Arctic char (Salvelinus alpinus)
- 2004
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Ingår i: Reproductive Biology and Endocrinology. - : Springer Science and Business Media LLC. - 1477-7827. ; 2, s. 62-
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Tidskriftsartikel (refereegranskat)abstract
- This study was performed to investigate stress effects on the synthesis of egg yolk precursor, vitellogenin (Vtg) in Arctic char (Salvelinus alpinus). In particular the effect of cortisol (F) was determined since this stress hormone has been suggested to interfere with vitellogenesis and is upregulated during sexual maturation in teleosts. Arctic char Vtg was purified and polyclonal antibodies were produced in order to develop tools to study regulation of vitellogenesis. The Vtg antibodies were used to develop an enzyme-linked immunosorbent assay. The corresponding Vtg cDNA was cloned from a hepatic cDNA library in order to obtain DNA probes to measure Vtg mRNA expression. Analysis of plasma from juvenile Arctic char, of both sexes, exposed to different steroids showed that production of Vtg was induced in a dose dependent fashion by 17beta-estradiol (E2), estrone and estriol. Apart from estrogens a high dose of F also upregulated Vtg. In addition, F, progesterone (P) and tamoxifen were tested to determine these compounds ability to modulate E2 induced Vtg synthesis at both the mRNA and protein level. Tamoxifen was found to inhibit E2 induced Vtg mRNA and protein upregulation. P did not alter the Vtg induction while F reduced the Vtg protein levels without affecting the Vtg mRNA levels. Furthermore the inhibition of Vtg protein was found to be dose dependent. Thus, the inhibitory effect of F on Vtg appears to be mediated at the post-transcriptional level.
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