Regulation by gonadal steroids of estrogen and progesterone receptors along the reproductive tract in female lambs.

The regulation of estrogen and progesterone receptor (ER, PR) expression by estradiol (E2) and progesterone (P4) in the oviduct, uterus and cervix of female lambs was studied. The animals received three intramuscular injections of E2, P4 or vehicle with an interval of 24 h and they were slaugthered 24 h after the third injection. Determinations of ER and PR were performed by binding assays and mRNAs of ER alpha and PR by solution hybridization. High levels of ER and PR in both cervix and oviduct were found in the female lamb, differing from other mammalian species. No significant effects by either E2 or P4 treatment on ER and PR levels in the cervix and oviduct could be observed. E2 treatment increased the mRNA levels of ERa and PR more than 3-fold in the cervix, while P4 treatment increased the mRNA levels of ERa and PR in the uterus. The results show differential effects of gonadal steroids on sex steroid receptor expression along the reproductive tract in female lambs, suggesting that steroid target tissues can modulate responses to the same circulating levels of steroid hormones.     

传染性支气管炎病毒感染对蛋雏鸡输卵管雌激素受体及孕激素受体表达的影响

以不同传染性支气管炎病毒（肾型IBV-河北分离株与呼吸型IBV-M41）分别感染蛋雏鸡,通过测定输卵管蛋白分泌部及子宫雌激素受体（Estrogen receptor,ER）和孕激素受体（Progesterone receptor,PR）的表达水平,来探讨IBV早期感染（10d）对抑制蛋鸡输卵管发育的作用机制。结果显示,IBV感染降低子宫和蛋白分泌部ER mR-NA、PR mRNA的表达水平,即致子宫ER mRNA和PR mRNA的表达低于检测水平;蛋白分泌部ER mRNA和PR mRNA的表达水平显著降低（P〈0.01）,且M41的作用幅度较肾型IBV更为显著（P〈0.01）。结果表明,IBV可通过降低ER和PR的表达水平,抑制输卵管对雌激素的应答能力而影响输卵管的发育。     

M41型IBV对输卵管中雌激素、孕激素受体及胰岛素生长因子-Ⅰ表达的影响

本试验通过相对定量RT-PCR检测接种M41型鸡传染性支气管炎病毒(infectious bronchitis virus,IBV)对蛋鸡输卵管各部分(蛋白部、峡部、伞部和子宫)雌激素受体(ER)、孕激素受体(PR)及胰岛素生长因子-Ⅰ(IGF-Ⅰ)mRNA表达的影响,研究IBV早期感染(10 d)抑制蛋鸡输卵管发育的作用机制。结果显示,输卵管各部均有ER、PR和IGF-Ⅰ mRNA的表达,染毒组ER、PR mRNA的表达量较正常对照组显著减少(P＜0.05),而IGF-Ⅰ的表达量较正常对照组显著增加(P＜0.05)。可见IBV可通过降低ER和 PR mRNA的表达水平,抑制输卵管对雌激素的应答能力而影响输卵管的发育;而IGF-Ⅰ可能是以自分泌、旁分泌方式在输卵管局部起作用,是输卵管生长的调节因子。     

Real-time RT-PCR quantification of pregnancy-associated plasma protein-A mRNA abundance in bovine granulosa and theca cells: effects of hormones in vitro

Ovarian follicular growth and dominance are controlled by a series of hormonal and intraovarian events including a decrease in intrafollicular IGF-binding proteins −2, −4 and −5 levels. Proteolytic enzymes such as pregnancy-associated plasma protein-A (PAPP-A) degrade IGFBPs and increase bioavailability of IGF-I and -II during follicular development. The objective of this study was to determine the effect of IGF-I, IGF-II, insulin (INS), LH, FSH, estradiol (E2), leptin or cortisol on ovarian PAPP-A mRNA levels. Granulosa (GC) from small (SM) (1–5 mm) and large (LG) (8–22 mm) follicles as well as theca cells (TC) from LG follicles were collected from bovine ovaries and cultured for 48 h in medium containing 10% FCS and then treated with various hormones in serum-free medium for an additional 24 h. Cells were treated with various concentrations (3–500 ng/ml) and combinations of IGF-I, IGF-II, FSH, LH, E2, INS, leptin and (or) cortisol for 24 h (Experiments 1–10). PAPP-A mRNA levels were measured using quantitative real-time RT-PCR. In SM-GC and LG-GC, none of the treatments significantly affected (P > 0.10) PAPP-A mRNA abundance. In LG-TC, IGF-I, LH or cortisol did not affect (P > 0.10) PAPP-A mRNA levels, whereas INS with or without LH decreased (P < 0.05) PAPP-A mRNA. E2 alone decreased PAPP-A mRNA levels in LG-TC, and E2 amplified the insulin-induced inhibition of PAPP-A mRNA abundance in LG-TC. We conclude that control of PAPP-A mRNA abundance in granulosa and theca cells differs, and that E2 may be part of an intraovarian negative feedback system which may reduce the bioavailable IGFs in the theca layer during growth and selection of follicles.     

Sex differences in oestrogen receptor levels in adrenal glands of sheep during the breeding season

The concentrations of the oestrogen receptor (ER), and the mRNA levels of ER, progesterone receptor (PR) and insulin-like growth factor I (IGF-I) were characterised in adrenal glands and uterine tissue of adult Corriedale sheep during the breeding season. The sheep were of different sex and gonadal status. Ewes had higher levels of cytosolic ER in the adrenals than the rams (mean±S.E.M.: 7.3±2.0 fmol/mg protein and 2.5±1.0 fmol/mg protein, respectively; P=0.0091) and gonadectomy increased ER (mean±S.E.M.: 2.9±1.2 fmol/mg protein and 8.6±2.3 fmol/mg protein, intact and gonadectomised sheep, respectively; P=0.0071). No differences could be observed in mRNA levels for ER and IGF-I in the adrenal glands of all of the sheep. PR mRNA levels were reduced in ovariectomised ewes and enhanced in castrated rams (sex×gonadal status: P=0.009). PR mRNA levels tended to be higher in ewes in the follicular phase than in ovariectomised ewes and intact rams (P<0.1). All of the animals had positive nuclear staining for ER in the adrenal cortex, but no differences were observed between the groups. In this study, we demonstrated the existence of ER in the adrenal gland of sheep and found varying sensitivity to oestrogens as the ER levels differed among sex and gonadal status. These findings indicate that oestrogens most likely affect steroidogenesis directly at the adrenal cortex and suggest that oestrogens are partly responsible for the sex differences in cortisol secretion in sheep.     

Feeding value for finishing beef steers of wheat grain conserved by different techniques

The objective was to determine the feeding value of high moisture grain as an alternative to dry grain for finishing beef cattle. Winter wheat grain was harvested sequentially for rolling, acid treatment and ensilage (ER; 705 g dry matter (DM)/kg), urea whole grain treatment and anaerobic storage (UN; 746 g DM/kg) and whole grain propionic acid treatment and aerobic storage (rolled before feeding; PR; 849 g DM/kg). Friesian steers (n = 120; mean starting live-weight 518 kg) were allocated on a live-weight basis to 12 replicate blocks and then randomly assigned from within blocks to ten treatments. Treatments were grass silage offered ad libitum together with (i) no wheat, (ii–iv) PR at 3 or 6 kg/head daily, or ad libitum, (v–vii) UN at equivalent DM allowances to (ii) and (iii) above, or ad libitum, (viii–x) ER at equivalent DM allowances to (ii) and (iii) above, or ad libitum. Mean daily live-weight gains were 852 (ER), 726 (UN) and 855 g (PR) (s.e. = 65.5; P < 0.05) with corresponding values for carcass gain of 522, 425 and 528 g (s.e. = 35.6; P < 0.001) and daily silage DM intakes of 3.5, 4.0 and 3.6 kg (s.e. = 0.15; P < 0.001). Wheat DM intake when offered ad libitum was 7.8, 8.3 and 8.2 kg (s.e. = 0.10; P < 0.05) for ER, UN and PR, respectively. The content of apparently undigested whole grains and starch in faeces was higher (P < 0.001) for UN than for ER and PR, particularly at higher rates of wheat ingestion. It is concluded that ER treatment of wheat grain can be an acceptable alternative to the more traditional PR and superior to the UN treatment in the diets of finishing beef cattle.     

Estrogen and progesterone receptor status of mammary carcinomas and correlation with clinical outcome in dogs.

Estrogen and progesterone receptors (ER, PR) were measured in cytosol fractions from 18 primary canine mammary carcinomas by use of biochemical assays. One or both receptors were detected (> 10 fmol/mg of cytosol protein) in 11 tumors: 5 ER and PR; 2 ER only; 4 PR only. Mean cytoplasmic receptor concentrations (fmol/mg of cytosol protein) were 22.8 +/- 2.9 (SEM) for ER and 51.0 +/- 10.3 for PR in tumors containing ER and PR, 28.8 +/- 12.1 for ER in tumors containing only ER and 13.2 +/- 1.5 for PR in tumors containing only PR. Estrogen or progesterone receptors or both were identified in 6 of 9 tubular adenocarcinomas, 4 of 5 papillary adenocarcinomas, and 1 of 1 squamous cell carcinoma. These receptors were not identified in solid carcinomas (n = 2) or a single spindle cell carcinoma. Although the number of cases was limited, survival times of dogs tended to be longest in those with tumors containing ER alone or in combination with PR, intermediate in those with tumors containing only PR, and shortest in those with tumors without ER or PR. A correlation was not apparent between receptor status and age, presence of ovaries, tumor size, or histologic classification of the tumor. In the analysis of this series, the extent of surgery (mastectomy of the involved gland vs unilateral or bilateral mastectomy) did not appear to influence the outcome of the disease, and metastasis to regional lymph nodes did not appear to be a reliable prognostic indicator.     

Estrogen and androgen receptor expression in relation to steroid concentrations in the adult boar epididymis

The steroid hormone regulation of the epididymis in a high estrogen producing animal like the boar is not currently understood. To test the hypothesis that the boar epididymis is an estrogen and androgen responsive tissue, the presence of estrogen and androgen receptors, in conjunction with steroid hormone concentrations were investigated in the boar epididymis. Epididymal (caput, corpus, cauda) and testicular samples of boars (1–2.5 years; n = 5) were collected for immunolocalization of estrogen receptor alpha (ER), estrogen receptor beta (ERβ) and androgen receptor (AR). Concentrations of testosterone, estradiol and estrogen conjugates (EC) in the tissue were also determined. AR and ERβ were localized in the principal and basal cells of all three epididymal regions. ER was localized in the principal cells of the caput, some cells of the corpus and was not present in the cauda. Testosterone (p < 0.0001), estradiol (p < 0.0001) and EC (p < 0.005) were significantly lower in the epididymis compared with the testis. The epididymal regions were not significantly different from each other for testosterone (p > 0.15) or estradiol (p > 0.09). EC were significantly higher in the corpus than either the caput (p = 0.003) or cauda (p = 0.002). These results suggest that the boar epididymis is responsive to both estrogens and androgens and that both steroid hormones are important for proper epididymal function. Since testosterone and estradiol concentrations are similar throughout the epididymis, regional differences in steroid hormone regulation are likely due to differences in receptor expression.     

Cytoplasmic estrogen and progesterone receptors in canine endometrium during the estrous cycle

Estradiol and progesterone receptors (ER, PR) were characterized and measured in cytosols from canine endometrium, using saturation and sucrose-gradient centrifugation radioassays. Both receptors were demonstrated to be steroid- and tissue-specific saturable proteins, which bound the respective steroids with high affinity (dissociation constant [Kd] approximately 10(-9)M). Serum estradiol, progesterone, and endometrial cytosol receptor concentrations and receptor-binding affinity were measured for 25 bitches from which samples were obtained at 5 stages of the estrous cycle (5 bitches each): anestrus (A), the 3rd day of proestrus (P3), the 3rd day of estrus (E3), the 12th day after onset of estrus (E12), and the 28th day after onset of estrus (E28). Mean (+/- SEM) serum estradiol concentrations were 17.0 +/- 2.2 (A), 55.4 +/- 5.0 (P3), 89.4 +/- 24.9 (E3), 41.0 +/- 5.9 (E12), and 50.6 +/- 3.9 (E28) pg/ml. Mean (+/- SEM) serum progesterone concentrations were 0.4 +/- 0.1 (A), 1.5 +/- 0.2 (P3), 17.3 +/- 7.5 (E3), 41.6 +/- 9.5 (E12), and 25.8 +/- 3.2 (E28) ng/ml. Concentrations of ER increased significantly from 1.06 pmol/g of uterus during stage A to a peak concentration of 6.18 pmol/g of uterus at E12, followed by a gradual decrease to 0.69 pmol/g of uterus by E28. The PR concentrations increased from 3.01 pmol/g of uterus in stage A to 17.32 pmol/g of uterus at P3; PR concentrations, thereafter, decreased gradually to 1.85 pmol/g of uterus by E28. Dissociation constants were significantly higher at E12 for the ER (Kd = 2.6645 X 10(-9)M) and at P3 for the PR (Kd = 5.8282 X 10(-9)M) than at the other stages examined, indicating a decrease in receptor affinity during the periods of high receptor concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in oestrogen,progesterone and epidermal growth factor receptor concentrations and affinities during the oestrous cycle in the normal mammary gland and uterus of dogs

Changes in the concentrations and affinities of receptors for oestrogen (ER), progesterone (PR) and epidermal growth factor (EGF-R) were studied in mammary glands of healthy bitches with regard to age, the location in the mammary chain and the stage of the oestrous cycle. Uterus was used as the reference tissue for the evaluation of steroid receptors. Mammary and uterine samples from 7 healthy bitches were taken at five stages of the oestrous cycle in such a way that all the locations in the mammary chain were represented at each stage of the cycle (10 samples/dog). ER, PR and EGF-R were detected by biochemical assays using increasing concentrations of tritiated (steroids) or iodinated (EGF) ligands. A significant direct correlation was found between the ER and PR concentrations for mammary and uterine samples. No significant correlation was found between the steroid receptors and EGF-R concentrations. Mammary ER concentrations were significantly higher in bitches of 5 years of age or older than in younger ones; in posterior glands (4th and 5th pairs) than in anterior glands; and in the mid-luteal phase. Mammary PR did not vary significantly with age or location but was significantly lower in the early luteal phase than in other phases. A similar decrease in PR concentrations was observed in the uterus during the early luteal phase and uterine ER and PR concentrations were very low in the mid-luteal phase. Mammary EGF-R were not significantly higher in the early or mid-luteal phase than in pro-oestrus or anoestrus.The differences observed between the uterine and mammary steroid receptor concentrations during the oestrous cycle could be due to different mechanisms for regulating steroid receptor expression in the two tissues. Mammary EGF-R concentrations may be linked, as in other species, to cellular proliferation and/or to the serum progesterone concentrations.Abbreviations BSA bovine serum albumin - EGF epidermal growth factor - EGF-R receptor for epidermal growth factor - ER oestrogen receptor - K _d dissociation constant - LH luteinizing hormone - p probability of error - PR progesterone receptor     

Effect of cereal type and exogenous enzyme supplementation in pig diets on odour and ammonia emissions

A 2 × 2 factorial experiment was conducted to investigate the interaction between cereal type (wheat vs. barley) and exogenous enzyme supplementation (with or without) on odour concentration and ammonia emissions in grower–finisher pigs. The enzyme supplement used contained Endo-1, 3 (4)-β-glucanase (EC 3.2.1.6) and Endo-1, 4-β-xylanase (E.C 3.2.1.8). The diets were formulated to contain similar levels of digestible energy and lysine. The experimental treatments were as follows: (1) wheat-based diet, (2) wheat-based diet containing a β-glucanase and β-xylanase mixed enzyme supplement, (3) barley-based diet and (4) barley-based diet containing a β-glucanase and β-xylanase mixed enzyme supplement. The diets were offered to the pigs for 4 weeks and this was repeated 4 times (n = 4). Odour and ammonia emissions were measured on days 9, 11, 14, 16, 21 and 23 of each experimental period. Odour samples were collected in 20-litre Nalophan bags and analysed for odour concentration using an ECOMA Yes/No Olfactometer. Ammonia concentrations were measured using Dräger tubes. There was a cereal × enzyme interaction in odour emission rates (P < 0.05) and in ammonia emissions (P < 0.01). The addition of an enzyme supplement increased odour emissions and had no effect on ammonia emissions in the barley-based diet. The enzyme supplementation had no effect on odour but decreased ammonia emissions in the wheat based diet.     

Expression and localization of estrogen receptors α and β mRNA in medullary bone of laying hens

The aim of this study was to observe the expression and localization of estrogen receptor (ER) α and ER β mRNA in the medullary bone of laying hens. First, medullary bone, liver, kidney, and shell gland of the oviduct tissues were dissected from laying hens. Then, the total cellular RNA was isolated from each tissue specimen, and the ER α and ER β mRNA expression was observed using semiquantitative RT‐PCR. Second, the localization of ER α mRNA in the medullary bone was detected with in situ hybridization using digoxigenin‐11‐UTP‐labeled cRNA probes. As a result, the expression of ER α mRNA was higher than that of ER β mRNA in the medullary bone, liver, and shell gland of the oviduct from laying hens. In the kidney, ER α mRNA expression was lower than that of ER β mRNA. The expression pattern of ER α and ER β mRNA of the medullary bone was similar to that of the shell gland of the oviduct. Moreover, ER α mRNA was intensively expressed in osteoblasts on the medullary bone surface and bone marrow stromal cells but was not expressed in osteoclasts. These results suggest that in medullary bone, estrogen action may be regulated not by ER β but by ER α.     

Skatole metabolism in the intact pre-pubescent male pig: The relationship between hepatic enzyme activity and skatole concentrations in plasma and fat

The objective of this study was to evaluate, in the pre-pubescent intact male pig, the relationship between skatole levels and the activity of hepatic cytochrome P4502E1 (CYP2E1), cytochrome P4502A (CYP2A), aldehyde oxidase (AO), and phenol sulfotransferase 1A1 (SULT1A1). The activity of these enzymes has been positively associated with skatole clearance in mature boars. Twenty-four intact male pigs were weaned at 28 days of age and slaughtered 2 weeks postweaning, at which time caecal contents, blood, fat, and liver samples were collected. Caecal contents and fat were analyzed for skatole concentrations, and plasma was analyzed for skatole and steroid hormone (testosterone (T), dehydroepiandrosterone (DHEAS), estrone sulphate (E₁S)) concentrations. CYP2A, CYP2E1, and AO, as well as SULT1A1 activities were evaluated in liver samples. Stepwise regression was utilized considering plasma or fat skatole concentration as the dependent variables and hormone concentrations and enzyme activities as independent variables. The activities of the enzymes CYP2A, CYP2E1, and AO and concentrations of the hormones T, DHEAS, or E₁S were not correlated with concentrations of skatole in plasma or fat. However, SULT1A1 activity was negatively correlated with plasma (r = − 0.70, P < 0.05) and backfat (r = − 0.41, P < 0.05) skatole concentrations. Furthermore, this correlation was improved in plasma (r = − 0.88, P < 0.05) and fat (r = − 0.63, P < 0.05) when the concentrations of skatole in caecal contents was included as an independent variable in the multiple regression analysis, demonstrating the importance of measuring skatole production in these studies. T, DHEAS, and E₁S concentrations in plasma were not correlated with the activity of any of the enzymes evaluated. This study suggests that SULT1A1 is important in the metabolism of skatole in pre-pubescent pigs and the overall metabolism of skatole in the pre-pubescent pig differs from that in the mature boar.     

Nuclear receptor and target gene mRNA abundance in duodenum and colon of dogs with chronic enteropathies

Nuclear receptors (NR), such as constitutive androstane receptor (CAR), pregnane X receptor (PXR) and peroxisome proliferator-associated receptors alpha and gamma (PPAR, PPARγ) are mediators of inflammation and may be involved in inflammatory bowel disease (IBD) and food responsive diarrhea (FRD) of dogs. The present study compared mRNA abundance of NR and NR target genes [multi drug-resistance gene-1 (MDR1), multiple drug-resistance-associated proteins (MRD2, MRD3), cytochrome P450 (CYP3A12), phenol-sulfating phenol sulfotransferase (SULT1A1) and glutathione-S-transferase (GST A3-3)] in biopsies obtained from duodenum and colon of dogs with IBD and FRD and healthy control dogs (CON; n = 7 per group). Upon first presentation of dogs, mRNA levels of PPAR, PPARγ, CAR, PXR and RXR in duodenum as well as PPARγ, CAR, PXR and RXR in colon were not different among groups (P > 0.10). Although mRNA abundance of PPAR in colon of dogs with FRD was similar in both IBD and CON (P > 0.10), PPAR mRNA abundance was higher in IBD than CON (P < 0.05). Levels of mRNA of MDR1 in duodenum were higher in FRD than IBD (P < 0.05) or CON (P < 0.001). Compared with CON, abundances of mRNA for MRP2, CYP3A12 and SULT1A1 were higher in both FRD and IBD than CON (P < 0.05). Differences in mRNA levels of PPAR and MRP2 in colon and MDR1, MRP2, CYP3A12 and SULT1A1 in duodenum may be indicative for enteropathy in FRD and (or) IBD dogs relative to healthy dogs. More importantly, increased expression of MDR1 in FRD relative to IBD in duodenum may be a useful diagnostic marker to distinguish dogs with FRD from dogs with IBD.