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1.
Fifty-three Angus and Hereford beef cows were utilized to investigate the effect of the conceptus on uterine environment during the period of pregnancy recognition. Blood samples were collected on Days 10, 12, 14, 16 and 18. Cows were randomly assigned to be either mated on the subsequent oestrus or serve as cyclic controls. Blood samples were then collected daily from Day 10 until slaughter on Day 15, 16 or 17 from the initiation of oestrus. Uteri were flushed with physiological saline and flushings analyzed for quantitative and qualitative protein changes, calcium, oestradiol-17β and prostaglandin F content. Endometrial explants of caruncular and intercaruncular tissue, and conceptus tissue recovered from pregnant cows were cultured with [3H]-leucine to determine quantitative and qualitative polypeptide synthesis and release. Plasma progesterone concentrations were similar between pregnant and cyclic cows from Day 10 through 17. Only the uterine content of prostaglandin F significantly increased in the ipsilateral horn of pregnant cows on Days 16 and 17. This increase in prostaglandin content was related to the increase in conceptus length from 25 to 40–80 mm. Conceptus production of bovine trophoblastic protein-1 was also first clearly detectable in fluorographs of medium from conceptuses measuring 25 mm. The complexity of the polypeptides present in the medium increased with conceptus development. Polypeptide synthesis by the endometrium was similar between tissues and days; however, production of two groups of low molecular weight basic polypeptides continued to be intensified on fluorographs from the pregnant horn on Day 17 compared to cyclic cows.  相似文献   

2.
Maternal heat stress in cattle may disrupt pregnancy by elevating uterine prostaglandin F(2alpha) (PGF(2alpha)) secretion. The objectives of this study were to determine the effects of elevated temperature (42 degrees C) in vitro upon 1) prostaglandin secretion by endometrial tissue; 2) the actions of extracellular regulators of uterine PGF [conceptus secretory proteins (bCSPs) and platelet-activating factor, (PAF)]; 3) the activity of the cyclooxygenase-endoperoxidase enzyme complex (PG synthetase); and 4) the activity of the endometrial PG synthesis inhibitor present in the endometrium from pregnant cattle. Endometrial explants at Day 17 of the estrous cycle produced more PGF than PGE(2) while elevated temperature caused increased PGF secretion but did not affect PGE(2) secretion. Elevated temperature did not reduce the ability of bCSPs or PAF to suppress release of PGF. The heat shock-induced increase in PGF at Day 17 was not due to the direct effects on PG synthetase, because PGF production from a cell-free cotyledonary microsomal enzyme preparation was reduced at elevated temperature. The activity of the cytosolic inhibitor of cyclooxygenase present in the endometrium of Day-17 pregnant cows could be reduced but not eliminated at 42 degrees C. We conclude that in vitro heat stress induces PGF secretion from the bovine uterine endometrium at Day 17 after estrus. This increase is not accompanied by the loss of regulatory capacity of conceptus products or increased activity of PG synthetase.  相似文献   

3.
Fifteen crossbred gilts were used to determine the influence of heat stress during Days 8 to 16 after onset of estrus on the development of conceptuses and uterine and endocrine functions. Ten gilts were bred 12 and 24 h after the onset of estrus (Day 0), and five gilts were nonbred controls. On Day 5, catheters were inserted into the uterine-ovarian vein (UV), saphenous artery (SA) and saphenous vein (SV) of each gilt. An electromagnetic blood flow transducer was implanted around the main uterine artery. Pregnant (n=5) and nonbred (n=5) control gilts were exposed to 21 +/- 1 degrees C, and pregnant heat-stressed gilts (n=5) were exposed to 37 +/- 1 degrees C for 12 h and 32 +/- 1 degrees C for 12 h daily during Days 8 through 16 after estrus. Treatment did not influence the partial pressure of oxygen (PO(2)) and of carbon dioxide (PCO(2)) in the UV, SA and SV blood. Uterine blood flow was not altered by heat stress. On Day 16, total wet weight of conceptuses was reduced in the gilts that were heat-stressed compared with conceptuses from control gilts. Incorporation of (3)H-leucine into macromolecules in vitro by conceptuses from the heat-stressed gilts was reduced compared with control gilts. Concentrations of 15-keto-13, 14-dihydro prostaglandin F(2alpha) (PGFM) in peripheral blood were greater than 1 ng/ml between Days 13 to 16 after estrus in 20% of the pregnant control gilts, 60% of the heat-stressed pregnant gilts, and 100% of the nonbred gilts. Concentrations of estradiol in the SA were affected by treatment. These results indicate that heat stress of gilts between Days 8 to 16 after estrus reduced the amount of conceptus tissue and altered concentrations of estradiol in the peripheral circulation, but uterine blood flow and PO(2) and PCO(2) in blood were not affected.  相似文献   

4.
Intrauterine infusion of enriched bovine trophoblast protein-1 complex (bTP-1) resulted in extension of interoestrous intervals and corpus luteum function in cyclic cattle. Conceptus proteins were obtained by culture of Day 17-18 conceptuses for 72 h. Media from the first (n = 28), second (n = 26) and third (n = 19) 24 h of conceptus incubations were utilized. A highly enriched preparation of bTP-1 was obtained by a combination of ammonium sulphate precipitation, ion-exchange chromatography, and h.p.l.c. gel filtration. Degree of purity of the final preparation was confirmed by gel electrophoresis and immunoblotting with antiserum to ovine trophoblast protein-1. Jersey cattle (3 per group) received intrauterine infusions, twice daily from Day 15.5 to 21.0, of bovine serum albumin, the entire array of bovine conceptus secretory proteins (bCSP) from the 3 days of conceptus culture, or bTP-1. Infusions were via a catheter into the uterine horn ipsilateral to the corpus luteum. Oestrous cycle length in bTP-1-treated cows (26.1 +/- 1.3 days) was greater than for cows given BSA (19.5 +/- 1.3 days) or bCSP (21.5 +/- 1.3 days). Similarly, progesterone concentrations in serum remained elevated for a longer period of time for bTP-1-treated cows than for cows treated with BSA or bCSP. Residual variance associated with vena cava concentrations of PGF-2 alpha at Days 19-21 after oestrus (which included the variance between 15-min periods within cows) was reduced in cows treated with bTP-1 as compared to other groups. Lack of a bCSP effect may have been due to low amounts of bTP-1 in conceptus-conditioned medium from cultures of greater than 24 h. None the less, purified bTP-1 was effective in extending luteal function and appears to be the antiluteolytic agent of early pregnancy.  相似文献   

5.
Blood flow to each uterine horn of cows during the oestrous cycle and early pregnancy was determined daily by use of electromagnetic blood flow probes placed around both middle uterine arteries. The pattern of blood flow to uteri of pregnant and non-pregnant cows was similar until Day 14 after mating or oestrus. Between Days 14 and 18 of pregnancy blood flow to the uterine horn containing the conceptus increased (P less than 0.01) 2- to 3-fold, whereas blood flow to the non-gravid uterine horn in these cows remained constant. No corresponding increase in blood flow to the uterine horn ipsilateral to the ovary bearing the CL was observed in non-pregnant cows during this 4-day period. By Day 19 of pregnancy, blood flow to the gravid uterine horn had returned to a level similar to that observed on Day 13. Blood flow to both uterine horns of pregnant cows remained constant from Days 19 to 25 and then increased to the gravid horn (P less than 0.01) markedly until Day 30 whereas blood flow to the non-gravid horn remained low. Uterine blood flow during the oestrous cycle of non-pregnant cows was positively correlated (P less than 0.01) with systemic concentrations of oestradiol and the ratio of oestradiol (pg/ml) to progesterone (ng/ml). There was no association between oestradiol concentrations and blood flow to the gravid uterine horn. These data indicate local control of uterine blood flow by the bovine conceptus which may function to create optimal conditions for the continuation of pregnancy.  相似文献   

6.
Fifty-one cyclic beef cows were mated with fertile bulls. At 36 h after the start of oestrus, cows were assigned to receive sesame oil (controls) or progesterone (100 mg) on Days 1, 2, 3 and 4 of pregnancy. Peripheral plasma concentration of progesterone was measured until slaughter on Days 5 or 14. Cows were randomly assigned to be slaughtered on Days 5 or 14 or remain intact and palpated per rectum on Day 40 to verify pregnancy. Uteri on Days 5 and 14 were flushed for recovery of luminal protein and conceptus tissue. Conceptus and endometrial tissues were cultured with [3H]leucine and submitted to two-dimensional-PAGE and fluorography. Administration of progesterone increased peripheral plasma progesterone concentration on Day 2-5. Conceptuses recovered from progesterone-treated cows on Day 14 were advanced in development compared to conceptuses from control cows. Conceptuses recovered from progesterone-treated cows were viable as polypeptides associated with maintenance of pregnancy in cattle were synthesized and released at an earlier time and pregnancy was maintained beyond Day 40. Early progesterone stimulation altered the synthesis and release of polypeptides from endometrial explant cultures on Day 5. Results indicate a role of progesterone in the maternal regulation of conceptus growth and development in early pregnancy of cattle.  相似文献   

7.
This paper demonstrates that a group of proteins, representing a major secretory component of cattle conceptuses, is immunologically related to ovine trophoblast protein-1 (oTP-1), a principal product of culture Day 13 to 21 sheep conceptuses. Conceptuses from cows (Day 17-18) and ewes (Day 16-17) were cultured for 24 h in the presence of L-[3H]leucine. By using a rabbit antiserum to oTP-1 and Ouchterlony double-immunodiffusion analysis it was shown that material in the bovine conceptus culture medium was serologically related, but not identical, to oTP-1. A solid-phase radiobinding assay indicated that the cross-reacting bovine secretory component had an affinity for anti-oTP-1 antibody similar to that of oTP-1. Anti-oTP-1 antiserum specifically immunoprecipitated a group of 6-8 polypeptides from culture medium of cow conceptuses which, when analysed by two-dimensional gel electrophoresis, fell into two major molecular weight classes (22,000 and 24,000) with isoelectric points between 6.5 and 6.7. These immunoprecipitated polypeptides, defined as bTP-1, constituted the major secretory products of Day 16-25 cow conceptuses. They were larger and more basic than oTP-1 polypeptides (Mr about 18,000; pI 5.4-5.7). Anti-oTP-1 antiserum also recognized the major translation product of Day 17 bovine conceptus mRNA, a polypeptide significantly smaller (Mr approximately 18,000) than the secreted protein. It is suggested that oTP-1 and the homologous bovine protein may play similar roles in the phenomenon of maternal recognition of pregnancy in the two species.  相似文献   

8.
In Exp. 1, administration of 5 mg oestradiol valerate i.m. to pregnant gilts on Days 9 or 9 and 10 advanced the uterine secretion of calcium, protein, and acid phosphatase as demonstrated by levels recovered in the uterine flushings of females unilaterally hysterectomized on Day 11. Upon removal of the remaining uterine horn on Day 12, protein and acid phosphatase increased while Ca2+ decreased in oestradiol-treated gilts as did PGF. In contrast, a 4-fold increase in recoverable Ca2+ occurred from Days 11 to 12 in control gilts. Recoverable oestradiol-17 beta was increased in all 3 groups on Day 12 and plasmin inhibitor concentration increased in oestradiol-treated gilts. Two-dimensional PAGE demonstrated the appearance of a group of very acidic polypeptides in oestradiol-treated gilts. Blastocysts recovered from the second uterine horn had undergone elongation to the filamentous morphology in all 3 groups. In Exp. 2, oestradiol valerate was administered to pregnant gilts on Day 9 or Days 9 and 10 followed by total hysterectomy on Day 16. No differences in recoverable Ca2+ or protein were found, but acid phosphatase was decreased by 75% after oestradiol treatment. Recoverable oestradiol was decreased in oestradiol-treated gilts while PGF and plasmin inhibitor concentrations were unaffected. Compared with the control gilts, blastocysts recovered from oestradiol-treated gilts were fragmented and degenerating on Day 16. PAGE demonstrated greatly intensified staining of the group of acidic polypeptides in oestradiol-treated gilts. These results indicate that oestradiol treatment on Day 9 of pregnancy advances uterine secretory response, but that blastocyst elongation can occur in this uterine environment and in the presence of declining intraluminal Ca2+ levels.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

9.
Maternal recognition of pregnancy in the cow requires successful signaling by the conceptus to block luteolysis. Conceptus growth and function depend on an optimal uterine environment, regulated by luteal progesterone. The objective of this study was to test strategies to optimize luteal function, as well as prevent a dominant follicle from initiating luteolysis. Nelore (Bos taurus indicus) beef cows (n=40) were submitted to a GnRH/PGF(2alpha)/GnRH protocol. Cows that ovulated from a dominant ovarian follicle (ovulation=Day 0) were allocated to receive: no additional treatment (G(C); n=7); 3000IU of hCG on Day 5 (G(hCG); n=5); 5mg of estradiol-17beta on Day 12 (G(E2); n=6); or 3000IU of hCG on Day 5 and 5mg of estradiol-17beta on Day 12 (G(hCG/E2); n=5). Ultrasonographic imaging of the ovaries, assessment of plasma progesterone concentration, and detection of estrus were done daily from Day 5 to the day of subsequent ovulation. Treatment with hCG induced an accessory CL, increased CL volume, and plasma progesterone concentration throughout the luteal phase (P<0.01). Estradiol-17beta induced atresia and recruitment of a new wave of follicular growth; it eliminated a potentially estrogen-active, growing ovarian follicle within the critical period for maternal recognition of pregnancy, but it also hastened luteolysis (Days 16 or 17 vs. Days 18 or 19 in non-treated cows). In conclusion, the approaches tested enhanced luteal function (hCG) and altered ovarian follicular dynamics (estradiol-17beta), but were unable to extend the life-span of the CL in Nelore cows.  相似文献   

10.
Prostaglandin F2alpha secretion by the uterine endometrium between Days 13 and 14 postovulation causes luteal regression in mares. A mechanism involving interruption or suppression of this secretion causes pregnancy to be maintained. The present study was designed to determine the age of the conceptus when maximal suppression of PGF2alpha secretion occurs. Mares were examined daily during estrus with ultrasonography (day 0 = day of ovulation). Conceptus tissues were recovered nonsurgically on Days 9 (n = 7), 12 (n = 5), 13 (n = 5), and 16 (n = 7) and uterine biopsies on Day 14. Both uterine and conceptus tissues were washed in phosphate-buffered saline (PBS) with 100 units penicillin G/ml + 100 microg streptomycin/ml, pH 7.4. Endometrial tissue (approximately 200 mg) plus conceptus tissues were incubated in 15 ml of tissue culture medium 199 (M199) + 10% fetal calf serum and 10 units penicillin G/ml and 10 microg streptomycin/ml at 37 degrees C under 5% CO(2): 5% O(2) : 90% N(2). Samples were taken at 4, 8, and 24 h. Two plates that contained only endometrial tissue and two additional plates with 25 mg flunixin meglumine added along with endometrial tissue were also included in the incubations. Concentrations of PGF2alpha were measured in all samples using radioimmunoassay. There was a trend toward suppression of PGF2alpha secretion by conceptus tissues, regardless of age. However, Day 12 concepti significantly suppressed PGF2alpha secretion compared with that of endometrial tissue incubated alone (P = 0.03).  相似文献   

11.
Endometrial explant cultures were prepared from 16 Brahman x Angus cows killed on Days 0, 2, 5 or 8 after oestrus. Cultures proceeded for 24 h at 39 degrees C (homeothermic) or 43 degrees C (heat shock) in a modified Eagle's minimal essential medium supplemented with 50 microCi L-[4,5(-3)H]leucine. Analysis by two-dimensional polyacrylamide gel electrophoresis of de-novo synthesized proteins secreted into the medium indicated that the major types of secreted polypeptides did not change over Days 0-8. Nevertheless, overall endometrial secretion of protein (incorporation of [3H]leucine into non-dialysable radioactivity in culture supernatants) was greatest at Day 0 and declined thereafter. Incorporation of [3H]leucine into TCA-precipitable material in tissue homogenates was also greatest at Day 0. For tissue cultured at 39 degrees C, several individual polypeptides were secreted at greater rates by endometrium from the horn of the uterus ipsilateral to the corpus luteum, with side differences tending to be greatest at Day 0 or Day 2. Overall, secretion of de-novo synthesized protein by endometrium was significantly elevated by heat shock at Day 0, but not affected thereafter. Nonetheless, heat shock reduced secretion of several individual proteins and exhibited interactions with day of the oestrous cycle and with side of the uterus. Secretion of 7 polypeptides was reduced by heat shock in tissue from the ipsilateral horn of the uterus but not in endometrium from the contralateral horn. We suggest that endometrial protein secretion changes quantitatively during the early oestrous cycle. In addition, there is a local influence of the ovary bearing the corpus luteum on endometrial function that may be disrupted by heat shock.  相似文献   

12.
Pregnancy rates following transfer of an in vitro-produced (IVP) embryo are often lower than those obtained following transfer of an embryo produced by superovulation. The purpose of the current pair of experiments was to examine two strategies for increasing pregnancy rates in heat stressed, dairy recipients receiving an IVP embryo. One method was to transfer two embryos into the uterine horn ipsilateral to the CL, whereas the other method involved injection of GnRH at Day 11 after the anticipated day of ovulation. In Experiment 1, 32 virgin crossbred heifers and 26 lactating crossbred cows were prepared for timed embryo transfer by being subjected to a timed ovulation protocol. Those having a palpable CL were randomly selected to receive one (n = 31 recipients) or two (n = 27 recipients) embryos on Day 7 after anticipated ovulation. At Day 64 of gestation, the pregnancy rate tended to be higher (P = 0.07) for cows than for heifers. Heifers that received one embryo tended to have a higher pregnancy rate than those that received two embryos (41% versus 20%, respectively) while there was no difference in pregnancy rate for cows that received one or two embryos (57% versus 50%, respectively). Pregnancy loss between Day 64 and 127 only occurred for cows that received two embryos (pregnancy rate at Day 127=17%). Between Day 127 and term, one animal (a cow with a single embryo) lost its pregnancy. There was no difference in pregnancy rates at Day 127 or calving rates between cows and heifers, but females that received two embryos had lower Day-127 pregnancy rates and calving rates than females that received one embryo (P < 0.03). Of the females receiving two embryos that calved, 2 of 5 gave birth to twins. For Experiment 2, 87 multiparous, late lactation, nonpregnant Holstein cows were synchronized for timed embryo transfer as in Experiment 1. Cows received a single embryo in the uterine horn ipsilateral to the ovary containing the CL and received either 100 microg GnRH or vehicle at Day 11 after anticipated ovulation (i.e. 4 days after embryo transfer). There was no difference in pregnancy rate for cows that received the GnRH or vehicle treatment (18% versus 17%, respectively). In conclusion, neither unilateral transfer of two embryos nor administration of GnRH at Day 11 after anticipated ovulation improved pregnancy rates of dairy cattle exposed to heat stress.  相似文献   

13.
The objective of this study was to determine the relationship between maternal progesterone concentration and conceptus synthesis of interferon-tau as an index of conceptus viability at the time of maternal recognition of pregnancy. Heifers of mixed beef breeds were randomly assigned to receive 1 of 2 treatments: 1) intramuscular injection of 1500 IU hCG on Day 5 after artificial insemination (AI; n = 12) or 2) intramuscular injection of saline on Day 5 after AI (n = 17). Ovaries were scanned daily by transrectal real-time ultrasonography. Progesterone concentrations were determined from daily blood samples collected from the jugular vein. Heifers were slaughtered on Day 18 after AI and conceptus tissues were collected. These were incubated individually at 37 degrees C in RPMI medium, and supernatant collected after 24 h. Conceptus secretory products in the supernatant were analyzed for interferon concentration by antiviral assay using vesicular stomatitis virus. Transrectal ultrasonography showed all heifers that received hCG had at least 1 extra corpus luteum (CL) in addition to the spontaneous CL formed from the previous ovulation (10 with 2 CL, 2 with 3 CL). A significant increase in plasma progesterone concentration was detected in pregnant heifers treated with hCG (n = 9) vs pregnant control heifers (n = 11; P < 0.001). There was a tendency for an increase (P = 0.059) in synthesis of interferon-tau by conceptuses from hCG-treated heifers compared to control heifers. Maternal plasma progesterone concentrations were correlated with interferon-tau production by the conceptuses (r = 0.593, P < 0.006), suggesting that higher maternal progesterone may provide a more suitable environment for the developing conceptus.  相似文献   

14.
Porcine conceptuses (embryo and associated membranes) in utero undergo developmental morphological transformations coincident with structural and biochemical changes in the uterine endometrium during early gestation. To elucidate a possible role for insulin-like growth factor-I (IGF-I) in these events, porcine endometrial (Days 8, 10, 11, 12, 14, and 30) and conceptus (Days 12, 14, and 16) tissues were characterized for the presence of IGF-I peptide and mRNAs. The corresponding uterine luminal fluids (ULF) at these stages of pregnancy were also analyzed for immunoreactive IGF-I concentration. ULF IGF-I was lowest on Day 8, highest on Day 12, and declined by Day 14. In contrast, endometrial tissue IGF-I content remained constant during this period. Conceptus tissues contained less IGF-I than endometrial tissues; however, conceptus IGF-I values were maximum on Day 12 coincident with peak values for ULF IGF-I. Dot-blot hybridization analyses revealed temporal variation in steady-state levels of IGF-I mRNAs in endometrium. Highest levels of endometrial IGF-I mRNA were detected on Day 12 and were about 4-fold greater than on Day 30 of pregnancy. IGF-I mRNA expression in conceptus tissues on Days 12, 14, and 16 was the same and was significantly less than that in endometrium on Day 12. These results demonstrate the temporal variation of IGF-I mRNA abundance in uterine endometrium and of immunoreactive IGF-I in ULF and in conceptus tissues, with the developmental processes occurring in the conceptuses at early pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

15.
Porcine conceptus secretory proteins (pCSP) were obtained from medium in which pig conceptuses, collected on Day 15 of pregnancy, were cultured for 30 h. Culture medium was pooled, dialyzed, and concentrated by Amicon ultrafiltration for intrauterine infusion. Serum proteins (SP) were obtained from blood collected from a Day 15 pregnant gilt and diluted for intrauterine infusion. Catheters were placed into both uterine horns and the inferior vena cava of cyclic (Day 8) gilts. Single blood samples were collected at 0800 h on Days 9, 10, and 11. On Day 11, all gilts received 1 mg estradiol-17 beta (E2) i.m. at 0800 h. Protein infusions commenced on Day 12 and continued through Day 15, twice daily at 0800 h and 2000 h. Protein infusions per uterine horn were (1) 4.0 mg pCSP + 4.0 mg SP (pCSP, 4 gilts) and (2) 8.0 mg SP (SP, 4 gilts). Blood samples were collected every 15 min on Days 12 through 17 between 0805 h and 1100 h. Single blood samples were collected at 0800 h after Day 17 until gilts exhibited estrus. Concentrations of prostaglandin (PG) E, 13,14-dihydro-15-keto-PGF2 alpha (PGFM), and progesterone (P4) were measured by specific radioimmunoassays. Interestrous intervals for pCSP-treated (18.2 days) and SP-treated (18.0 days) gilts were not different (SEM = 0.8 days) and temporal changes in concentrations of P4 in plasma did not differ between pCSP-treated (29.2 ng/ml) and SP-treated (31.2 ng/ml) gilts.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
Restriction of the conceptus to one uterine horn of the pregnant ewe results in the accumulation of fluid called uterine milk (UTM) in the contralateral horn. Two basic polypeptides, called the uterine milk proteins (UTM-proteins; Mr = 55,000 and 57,000 as determined by polyacrylamide-gel electrophoresis using sodium dodecyl sulfate), accounted for the majority of the protein in uterine milk. The two UTM-proteins were glycoproteins and were readily purified from uterine fluids by cation-exchange chromatography on carboxymethyl (CM)-cellulose followed by Sephacryl S-200 gel-filtration. The purified UIM-proteins had a weight-average molecular weight of 50,700 +/- 4,200, as determined by equilibrium sedimentation analysis. Endometrial explants from pregnant ewes were cultured in the presence of radioactive amino acids and released UTM-proteins into the medium as their major secretory products. The UTM-proteins were secreted into the uterine lumen of nonpregnant, ovariectomized ewes given daily injections of progesterone. Estrone alone was ineffective in inducing UTM-protein production. Immunocytochemical studies indicated that synthesis of the UTM-proteins was confined to the surface and glandular epithelium of the uterus.  相似文献   

17.
In Experiment 1, 12 unmated cyclic ewes received twice-daily intrauterine injections on Days 12 to 14 of one of the following treatments: 1) ovine conceptus secretory proteins (oCSP) containing 25 mug of ovine trophoblast protein-1 (oTP-1) as determined by RIA; 2) 25 or 50 mug recombinant human interferon alpha1 (rhlFN); or 3) 1500 ug of serum proteins (oSP) from a Day-16 pregnant ewe (estrus = Day 0) per uterine horn. Ewes receiving oCSP had longer interestrous intervals (27 +/- 2 days; P<0.05) than ewes receiving oSP (17 +/- 2 days). Ewes receiving either dose of rhlFN had an interestrous interval of 16 +/- 2 days which did not differ (P>0.10) from that of oSP-treated ewes. In Experiment 2, 59 normally cycling ewes, mated on Day 0, received twice-daily intramuscular injections of either 2 mg recombinant bovine interferon alpha1 (rblFN) or placebo on Days 12 to 15 post estrus. On Day 16, pregnancy was confirmed by flushing a morphologically normal conceptus from the uterus. Pregnancy rates for rblFN-treated (80%) and placebo-treated (62%) ewes were not different (P>0.10). Uterine flushings and conceptus-conditioned medium were assayed for oTP-1. Total oTP-1 in conceptus-conditioned culture medium was higher (P<0.02) when conceptuses were from placebo-treated (104 +/- 14 mug/conceptus) than from rblFN-treated (56 +/- 12 mug/conceptus) ewes; while total oTP-1 in uterine flushings was similar (P>0.10) for placebo-treated (132 +/- 15 mug/conceptus) and rblFN-treated (147 +/- 17 mug/conceptus) ewes. The interval from mating to subsequent estrus following conceptus removal was 31 +/- 1 and 28 +/- 1 days for pregnant ewes treated with rblFN and placebo, respectively. Interestrous intervals for nonpregnant ewes were longer (P<0.02) for rblFN-treated (27 +/- 3 days) than for placebo-treated (18 +/- 2 days) ewes.  相似文献   

18.
Conceptus-uterine communication is established during trophoblastic elongation when the conceptus synthesizes and releases estrogen, the maternal recognition signal in the pig. Interleukin-1beta (IL-1beta) is a differentially expressed gene during rapid trophoblastic elongation in the pig. The current investigation determined conceptus and endometrial changes in gene expression for IL-1beta, IL-1 receptor antagonist (IL-1Rant), IL-1 receptor type 1 (IL-1RT1), and IL-1 receptor accessory protein (IL-1RAP) in developing peri- and postimplantation conceptuses as well as uterine endometrium collected from cyclic and pregnant gilts. Conceptus IL-1beta gene expression was enhanced during the period of rapid trophoblastic elongation compared with earlier spherical conceptuses, followed by a dramatic decrease in elongated Day 15 conceptuses. IL-1RT1 and IL-1RAP gene expression was greater in Day 12 and 15 filamentous conceptuses compared with earlier morphologies while IL-1Rant gene expression was unchanged by conceptus development. The uterine lumenal content of IL-1beta increased during the process of trophoblastic elongation on Day 12. Uterine IL-1beta content declined on Day 15, reaching a nadir by Day 18 of pregnancy. IL-1beta gene expression in porcine conceptuses was temporally associated with an increase in endometrial IL-1RT1 and IL-1RAP gene expression in pregnant gilts. Endometrial IL-1beta and IL-1Rant gene expression were lowest during Days 10-15 of the estrous cycle and pregnancy. The temporal expression of IL-1beta during conceptus development and the initiation of conceptus-uterine communication suggests conceptus IL-1beta synthesis plays an important role in porcine conceptus elongation and the establishment of pregnancy in the pig.  相似文献   

19.
The conceptus is believed to produce factors that regulate endometrial function and prevent luteolysis during early pregnancy. Endometrial tissues were collected from cyclic (n = 8) and pregnant (n = 2) cows at Day 17 post-estrus and cultured for 24 and 48 h with bovine conceptus secretory proteins (bCSP) (0%, 10%, 100%), where the amount of protein produced by a bovine conceptus during 24 h of culture is 100%. Incorporation of [3H]leucine into secreted proteins was determined and examined qualitatively by trichloroacetic acid precipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. Levels of an intracellular endometrial inhibitor of prostaglandin synthesis were determined with a cotyledonary microsomal test system. Treatment with 10% and 100% bCSP reduced incorporation of [3H]leucine into secreted proteins. However, bCSP selectively induced two secreted proteins (13 and 10 kDa) from endometrium of cyclic cows. Prostaglandin F (PGF) secretion was decreased by bCSP treatment while prostaglandin E2 secretion was unaltered. An intracellular endometrial inhibitor of prostaglandin synthesis was induced by bCSP; synthesis of PGF by the cotyledonary prostaglandin-generating system was decreased when incubated with cytosol of endometrium treated with bCSP, but unaltered by cytosol from control tissues. In conclusion, products produced by the bovine conceptus are capable of regulating endometrial protein and prostaglandin biosynthesis in a fashion that could act to prevent luteolysis in vivo and provide endometrial secretory products for embryonic development.  相似文献   

20.
Conceptus number was reduced to one on Day 7 of pregnancy in rats by aspirating all but a single conceptus (Group E) or left at greater than or equal to 8 conceptuses (Group C). In Group E rats, serum progesterone concentrations remained low from Day 12 until autopsy at Day 21. Hypophysectomy on Day 12 significantly increased serum progesterone values after Day 17 of pregnancy, and these increases were blocked by treatment with ACTH (10 U/day, i.p., Days 12-17). Adrenalectomy on Day 12 also induced slight, but statistically significant, increases in serum progesterone concentration after Day 17, and these were overcome by implantation of a 10 mg capsule of corticosterone. In Group C rats, hypophysectomy or adrenalectomy on Day 12 did not change serum progesterone concentrations, but 40 U ACTH/day inhibited progesterone secretion. We conclude from these results that the pituitary-adrenal system exerts inhibitory effects on progesterone secretion during mid-pregnancy in rats.  相似文献   

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