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1.
Rattanatrai CHAIYASING Takuro ISHIKAWA Katsuhiko WARITA Yoshinao Z. HOSAKA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(7):1022
This study aimed to investigate the function of estrogen receptors (ERs) in myoregeneration and intermuscular adipogenesis. Ovariectomized (OVX) ERα knockout (KO) mice and ERβ KO mice were used to assess the effect of estrogen on the myoregenerative process. Tibialis anterior muscle was collected on days 7, 10, and 14 after cardiotoxin injection to assess myotube morphology and adipogenesis area. Regenerated myotubes from OVX-ERβ KO mice were consistently smaller in diameter than those from OVX-ERα KO and OVX-wild-type mice, whereas the adipogenesis area of OVX-ERβ KO mice was consistently greater than that of the other types. Therefore, ERβ may be an influential factor in promoting myoregeneration and adipogenesis inhibition compared to ERα. 相似文献
2.
Takuya MURATA Kazumi NARITA Toru ICHIMARU 《The Journal of reproduction and development》2014,60(1):55-61
Estrogen action is mediated through several types of receptors (ERs), such as ERα, ERβ
and putative membrane ERs. Oxytocin receptor (OTR) and ER expression levels in the rat
uterus are regulated by estrogen; however, which types of ERs are involved has not been
elucidated. This study examined OTR, ERα and ERβ levels in ovariectomized rats treated
with 17β-estradiol (E2), an ERα agonist (PPT), an ERβ agonist (DPN) or estren (Es). E2 and
PPT increased OTR mRNA levels and decreased ERα and ERβ mRNA levels 3 and 6 h
posttreatment. DPN decreased ERα and ERβ mRNA levels at 3 and 6 h, while OTR mRNA levels
increased at 3 h and decreased at 6 h. OTR mRNA levels increased 3 h after the Es
treatment and then declined until 6 h. ERα and ERβ mRNA levels decreased by 3 h and
remained low until 6 h posttreatment with Es. The ER antagonist ICI182,780 (ICI)
suppressed the increases in OTR mRNA levels induced 3 h after the Es treatment. However,
ICI and tamoxifen (Tam) had no significant effect on ERα and ERβ mRNA levels in the
Es-treated or vehicle-treated group. In intact rats, proestrus-associated increases in OTR
mRNA levels were antagonized by both ICI and Tam. However, decreases in ERα and ERβ mRNA
levels were not antagonized by Tam and ICI, respectively. Therefore, uterine OTR gene
expression is upregulated by estrogen through the classical nuclear (or non-nuclear) ERs,
ERα and ERβ, while the levels of these ERs are downregulated by estrogen through multiple
pathways including Es-sensitive nonclassical ERs. 相似文献
3.
4.
Yoshie MANABE Makoto TOCHIGI Akiyoshi MORIWAKI Sakae TAKEUCHI Sumio TAKAHASHI 《The Journal of reproduction and development》2013,59(4):398-404
Reproductive functions decline with the onset of diabetes in female mice. Diabetic mice
have smaller uteri with an underdeveloped endometrium, suggesting diminished
estrogen-induced growth. We aimed to clarify the changes in the estrous cycle and in
insulin-like growth factor 1 (IGF1) expression in the uteri of streptozotocin
(STZ)-treated diabetic mice, because IGF1 is one of the main growth factors involved in
estrogen-induced uterine growth. ICR female mice were intraperitoneally administered STZ
(10 mg/100 g BW), and blood glucose levels were determined. Mice with blood glucose levels
> 200 mg/dl were classified as diabetic mice. The onset of diabetes was associated with
acyclic estrous cycles. Diabetes was also induced with STZ in ovariectomized mice. Uterine
Igf1 mRNA levels were reduced in ovariectomized STZ-treated diabetic
mice. Estrogen is known to stimulate Igf1 mRNA expression in the uterus,
but estrogen action was abolished in the uteri of STZ-treated diabetic mice. mRNA
expressions of estrogen receptor α (ERα) and steroid hormone receptor coactivators
(SRC-1/Ncoa1, SRC-2/Ncoa2,
SRC-3/Ncoa3 and CBP/p300/Crebbp) were reduced in the
uteri of ovariectomized STZ-treated diabetic mice. The present study demonstrates that
diabetes induces a decline in female reproductive functions in mice. Igf1
expression in ovariectomized diabetic female mice was decreased, and decreased
responsiveness to estrogen in the uteri of diabetic mice is probably associated with a
reduction in ERα and steroid receptor coactivator mRNA expression. 相似文献
5.
Yoshihisa UENOYAMA Akira TANAKA Kenji TAKASE Shunji YAMADA Vutha PHENG Naoko INOUE Kei-ichiro MAEDA Hiroko TSUKAMURA 《The Journal of reproduction and development》2015,61(4):351-359
The present study aimed to determine estrogen feedback action sites to mediate prepubertal restraint of gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) release in female rats. Wistar-Imamichi strain rats were ovariectomized (OVX) and received a local estradiol-17β (estradiol) or cholesterol microimplant in several brain areas, such as the medial preoptic area (mPOA), paraventricular nucleus, ventromedial nucleus and arcuate nucleus (ARC), at 20 or 35 days of age. Six days after receiving the estradiol microimplant, animals were bled to detect LH pulses at 26 or 41 days of age, representing the pre- or postpubertal period, respectively. Estradiol microimplants in the mPOA or ARC, but not in other brain regions, suppressed LH pulses in prepubertal OVX rats. Apparent LH pulses were found in the postpubertal period in all animals bearing estradiol or cholesterol implants. It is unlikely that pubertal changes in responsiveness to estrogen are due to a change in
estrogen receptor (ER) expression, because the number of ERα-immunoreactive cells and mRNA levels of Esr1, Esr2 and Gpr30 in the mPOA and ARC were comparable between the pre- and postpubertal periods. In addition, kisspeptin or GnRH injection overrode estradiol-dependent prepubertal LH suppression, suggesting that estrogen inhibits the kisspeptin-GnRH cascade during the prepubertal period. Thus, estrogen-responsive neurons located in the mPOA and ARC may play key roles in estrogen-dependent prepubertal restraint of GnRH/LH secretion in female rats. 相似文献
6.
The mechanism of spontaneous islet fibrosis in Sprague-Dawley rats was investigated. Using sections of the pancreas in naive males aged 26 to 102 weeks old and 26-week-old males injected with β-estradiol 3-benzoate (EB), the incidence of lesions and histological scores of fibrosis were examined in conjunction with immunohistochemistry for α-smooth muscle actin (α-SMA), platelet-derived growth factor receptor-α (PDGFRα) and estrogen receptor-α (ERα). The incidence of islet fibrosis increased in 78-week-old animals compared to the 26-week-old animals, and the incidence of atrophy in the fibrotic islet increased in animals over 52 weeks old. α-SMA and PDGFRα were positively stained mainly in fibrotic/inflammatory islets, and the histological score of α-SMA in the fibrotic islet decreased age-dependently. Notably, α-SMA and PDGFRα were co-expressed in inflammatory islets with a high score at all ages. The positive index of ERα in the EB-treated group increased when compared with that of the naive group. However, it was independent of the existence of fibrosis. In contrast, the score of α-SMA and PDGFRα decreased in the EB-treated group. In conclusion, it was clarified that a part of age-related fibrosis in islets became atrophy with age, and α-SMA-positive myofibroblasts were considered to contribute to the development of fibrosis. Strong PDGFRα stainability in fibrotic/inflammatory islets may imply that myofibroblasts were stimulated by PDGF to produce an extracellular matrix. Although estradiol has been known to suppress fibrosis/inflammation in the islet, nuclear-located ER-dependent signaling was considered not to be involved in the suppression mechanism. EB possibly affected the inhibition of the appearance of myofibroblasts. 相似文献
7.
Background
Cracked shells, due to age related reduction of shell quality, are a costly problem for the industry. Parallel to reduced shell quality the skeleton becomes brittle resulting in bone fractures. Calcium, a main prerequisite for both eggshell and bone, is regulated by estrogen in a complex manner. The effects of estrogen, given in a low continuous dose, were studied regarding factors involved in age related changes in shell quality and bone strength of laying hens. A pellet containing 0.385 mg estradiol 3-benzoate (21-day-release) or placebo was inserted subcutaneously in 20 birds each of Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) at 70 weeks of age. Eggs were collected before and during the experiment for shell quality measurements. Blood samples for analysis of total calcium were taken three days after the insertion and at sacrifice (72 weeks). Right femur was used for bone strength measurements and tissue samples from duodenum and shell gland were processed for morphology, immunohistochemical localization of estrogen receptors (ERα, ERβ), plasma membrane calcium ATPase (PMCA) and histochemical localization of carbonic anhydrase (CA).Results
Estrogen treatment increased shell thickness of both hybrids. In addition, shell weight and shell deformation improved in eggs from the brown hybrids. The more pronounced effect on eggs from the brown hybrid may be due to a change in sensitivity to estrogen, especially in surface epithelial cells of the shell gland, shown as an altered ratio between ERα and ERβ. A regulatory effect of estrogen on CA activity, but not PMCA, was seen in both duodenum and shell gland, and a possible connection to shell quality is discussed. Bone strength was unaffected by treatment, but femur was stronger in LSL birds suggesting that the hybrids differ in calcium allocation between shell and bone at the end of the laying period. Plasma calcium concentrations and egg production were unaffected.Conclusions
A low continuous dose of estrogen improves shell strength but not bone strength in laying hens at the end of the laying period. 相似文献8.
Yosuke SUGINO Taiki SATO Yuki YAMAMOTO Koji KIMURA 《The Journal of reproduction and development》2022,68(4):254
In ruminants, uterine glands play key roles in the establishment of pregnancy by secreting various factors into the uterine lumen. Although a three-dimensional (3D) culture system has been used for investigating cellular functions in vitro, the detailed functions of uterine gland have not been fully elucidated. In this study, we examined the benefits of 3D culture system to examine the innate functions of bovine uterine glands. Isolated bovine uterine glands were cultured on Matrigel (2D) or in Matrigel (3D), respectively, and the mRNA levels of secreted proteins (SERPINA14, MEP1B, APOA1, ARSA, CTGF, and SPP1) were measured in isolated and cultured uterine glands. The protein expression of estrogen receptor β (ERβ) and progesterone receptor (PR) and the establishment of apico-basal polarity were examined. In isolated uterine glands, the mRNA levels of secreted proteins changed during the estrous cycle. Although uterine glands cultured in both 2D and 3D expressed ERβ and PR, progesterone did not affect SERPINA14 mRNA expression. The expression of APOA1 mRNA in 2D cultured uterine glands did not respond to estrogen and progesterone. Additionally, the mRNA levels of secreted proteins in the 3D culture system were significantly higher than those in the 2D culture system, which might be attributed to the different cellular morphology between them. The locations of ZO-1 and β-catenin in 2D cultured uterine glands were disordered compared with 3D cultured uterine glands. These results showed that the hormonal responsiveness of secreted factor expression and cellular morphology were different between 2D and 3D cultured bovine uterine glands. 相似文献
9.
Midori Yoshida Shin-ichi Katsuda Akihiko Maekawa 《Journal of toxicologic pathology》2012,25(4):241-247
Involvements of estrogen receptor (ER)α, proliferating cell nuclear antigen (PCNA) and p53
in the uterine carcinogenesis process in Donryu rats, a high yield strain of the uterine cancer
were investigated immunohistochemically. ERα was expressed in atypical endometrial hyperplasia,
accepted as a precancerous lesion of the uterine tumors, as well as well- and in
moderately-differentiated endometrial adenocarcinomas, and the intensities of expression were
similar to those in the luminal epithelial cells of the atrophic uterus at 15 months of age.
The expression, however, was negative in the tumor cells of poorly differentiated type. Good
growth of implanted grafts of the poorly-differentiated adenocarcinomas in both sexes with or
without gonadectomy supported the estrogen independency of tumor progression to malignancy.
PCNA labeling indices were increased with tumor development from atypical hyperplasia to
adenocarcinoma. The tumor cells in poorly-differentiated adenocarcinomas were positive for p53
positive but negative for p21 expression, suggesting accumulation of mutated p53. These results
indicate that the consistent ERα expression is involved in initiation and promotion steps of
uterine carcinogenesis, but not progression. In addition, PCNA is related to tumor development
and the expression of mutated p53 might be a late event during endometrial carcinogenesis. 相似文献
10.
鸡血藤总黄酮对环磷酰胺所致小鼠肝损伤的保护作用 《畜牧与饲料科学》2022,43(4):8-13
目的 研究鸡血藤总黄酮对环磷酰胺所致小鼠肝损伤的保护作用。方法 将60只昆明系小鼠随机分为6组,每组10只,试验周期为7 d。对照组小鼠试验全程给予生理盐水。环磷酰胺(CTX)组小鼠1~4 d灌胃给予生理盐水;5~7 d腹腔注射80 mg/(kg·BW)CTX,每天给药1次。鸡血藤总黄酮(TFSD)100组、CTX+TFSD25组、CTX+TFSD50组、CTX+TFSD100组小鼠1~7 d分别灌胃给予100、25、50、100 mg/(kg·BW)TFSD,每天给药1次;试验5~7 d除TFSD100组小鼠腹腔注射生理盐水外,其余试验组腹腔注射80 mg/(kg·BW)CTX,每天给药1次。试验结束后对各组小鼠进行眼球采血及剖检;检测肝组织中超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)、黄嘌呤氧化酶(XOD)以及谷胱甘肽过氧化物酶(GSH-Px)活力,测定血清中谷草转氨酶(AST)、谷丙转氨酶(ALT)和碱性磷酸酶(ALP)活力,检测血清中肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)和白介素-1β(IL-1β)含量。结果 环磷酰胺可显著(P<0.05)降低小鼠肝脏中SOD、GSH-Px以及血清中ALT活力,显著(P<0.05)升高肝脏中XOD与MPO活力、血清中ALP活力以及炎症细胞因子IL-1β和IL-6释放水平。25、50、100 mg/(kg·BW)的TFSD处理均可显著(P<0.05)抑制由CTX引起的SOD活力降低,25 mg/(kg·BW)的TFSD处理可显著(P<0.05)提高CTX处理小鼠的GSH-Px活力;50 mg/(kg·BW)的TFSD处理可显著(P<0.05)抑制由CTX引起的XOD和MPO活力升高,且可显著(P<0.05)降低CTX处理小鼠血清中的AST活力;25、50、100 mg/(kg·BW)的TFSD处理可显著(P<0.05)抑制由CTX引起的血清中ALP活力升高,同时降低ALT活力。25、50、100 mg/(kg·BW)的TFSD处理均可显著(P<0.05)抑制由CTX引起的IL-1β水平升高。结论 鸡血藤总黄酮可通过调节小鼠炎症因子释放以及肝组织中氧化还原酶水平对环磷酰胺所致肝损伤提供保护,推荐剂量为25 mg/(kg·BW)。 相似文献
11.
Joanna PIASECKA-SRADER Agnieszka SADOWSKA Anna NYNCA Karina ORLOWSKA Monika JABLONSKA Olga JABLONSKA Brian K. PETROFF Renata E. CIERESZKO 《The Journal of reproduction and development》2016,62(1):103-113
Low doses of endocrine disrupting chemicals (EDCs) used in combination may act in a manner different from
that of individual compounds. The objective of the study was to examine in vitro effects of
low doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 100 pM) and genistein (500 nM) on: 1)
progesterone (P4) and estradiol (E2) secretion (48 h); 2) dynamic changes in aryl
hydrocarbon receptor (AhR) mRNA and protein expression (1, 3, 6, 24 and 48 h); 3) dynamic changes in estrogen
receptor β (ERβ) mRNA and protein expression (1, 3, 6, 24 and 48 h); and 4) induction of apoptosis in porcine
granulosa cells derived from medium follicles (3, 6 and 24 h). TCDD had no effect on P4 or
E2 production, but potentiated the inhibitory effect of genistein on P4 production. In
contrast to the individual treatments which did not produce any effects, TCDD and genistein administered
together decreased ERβ and AhR protein expression in granulosa cells. Moreover, the inhibitory effect of TCDD
on AhR mRNA expression was abolished by genistein. The treatments did not induce apoptosis in the cells. In
summary, combined effects of low concentrations of TCDD and genistein on follicular function of pigs differed
from that of individual compounds. The results presented in the current paper clearly indicate that effects
exerted by low doses of EDCs applied in combination must be taken into consideration when studying potential
risk effects of EDCs on biological processes. 相似文献
12.
Hamster sperm hyperactivation is enhanced by progesterone, and this progesterone-enhanced hyperactivation is suppressed by 17β-estradiol (17βE2) and γ-aminobutyric acid (GABA). Although it has been indicated that melatonin also enhances hyperactivation, it is unknown whether melatonin-enhanced hyperactivation is also suppressed by 17βE2 and GABA. In the present study, melatonin-enhanced hyperactivation was significantly suppressed by 17βE2 but not by GABA. Moreover, suppression of melatonin-enhanced hyperactivation by 17βE2 occurred through non-genomic regulation via the estrogen receptor (ER). These results suggest that enhancement of hyperactivation is regulated by melatonin and 17βE2 through non-genomic regulation. 相似文献
13.
Kei YOSHIDA Toshio MATSUOKA Yui KOBATAKE Satoshi TAKASHIMA Naohito NISHII 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(2):275
The present study aimed to quantitatively evaluate muscle mass and gene expression in dogs with glucocorticoid-induced muscle atrophy. Five healthy beagles received oral prednisolone for 4 weeks (1 mg/kg/day), and muscle mass was then evaluated via computed tomography. Histological and gene expression analyses were performed using biopsy samples from the biceps femoris before and after prednisolone administration. The cross-sectional area of the third lumbar paraspinal and mid-femoral muscles significantly decreased after glucocorticoid administration (from 27.5 ± 1.9 to 22.6 ± 2.0 cm2 and from 55.1 ± 4.7 to 50.7 ± 4.1 cm2, respectively; P<0.01). The fast- and slow-twitch muscle fibers were both atrophied (from 2,779 ± 369 to 1,581 ± 207 μm2 and from 2,871 ± 211 to 1,971 ± 169 μm2, respectively; P<0.05). The expression of the growth factor receptor-bound protein 10 (GRB10) significantly increased after prednisolone administration (P<0.05). Because GRB10 suppresses insulin signaling and the subsequent mammalian target of rapamycin complex 1 activity, increased expression of GRB10 may have resulted in a decrease in protein anabolism. Taken together, 1 mg/kg/day oral prednisolone for 4 weeks induced significant muscle atrophy in dogs, and GRB10 might participate in the pathology of glucocorticoid-induced muscle atrophy in canines. 相似文献
14.
Takuya HIROSE Takayuki OGURA Keisuke TANAKA Jun MINAGUCHI Takeshi YAMAUCHI Toshiyuki FUKADA Yoh-ichi KOYAMA Kazushige TAKEHANA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(11):1385-1389
Ehlers-Danlos syndrome (EDS) is a group of disorders caused by abnormalities that are
identified in the extracellular matrix. Transforming growth factor-β1 (TGF-β1) plays a
crucial role in formation of the extracellular matrix. It has been reported that the loss
of function of zinc transporter ZRT/IRT-like protein 13 (ZIP13) causes the spondylocheiro
dysplastic form of EDS (SCD-EDS: OMIM 612350), in which dysregulation of the TGF-β1
signaling pathway is observed, although the relationship between the dermis abnormalities
and peripheral TGF-β1 level has been unclear. We investigated the characteristics of the
dermis of the Zip13-knockout (KO) mouse, an animal model for SCD-EDS.
Both the ratio of dermatan sulfate (DS) in glycosaminoglycan (GAG) components and the
amount of collagen were decreased, and there were very few collagen fibrils with diameters
of more than 150 nm in Zip13-KO mice dermis. We also found that the
TGF-β1 level was significantly higher in Zip13-KO mice serum. These
results suggest that collagen synthesis and collagen fibril fusion might be impaired in
Zip13-KO mice and that the possible decrease of decorin level by
reduction of the DS ratio probably caused an increase of free TGF-β1 in
Zip13-KO mice. In conclusion, skin fragility due to defective
ZIP13 protein may be attributable to impaired extracellular matrix
synthesis accompanied by abnormal peripheral TGF-β homeostasis. 相似文献
15.
Wageh Sobhy DARWISH Yoshinori IKENAKA Alaa Eldin MORSHDY Kamal Ibrahim ELDESOKY Shouta NAKAYAMA Hazuki MIZUKAWA Mayumi ISHIZUKA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(2):351-354
The aim of this study was to estimate total carotenoids, β-carotene and retinol concentrations in the livers
and muscles of some ungulates (cattle, buffalo, sheep, goats and horses) in comparison with the Wistar rats as
a control. Cattle and horses had the highest contents of total carotenoids and β-carotene. Unexpectedly, sheep
was the highest accumulator of retinol with a mean concentration of 203 ± 23.34 µg/g, while
the least accumulator was buffalo, having a mean value of 58.28 ± 13.77 µg/g. Livers had
higher contents of the examined phytochemicals than muscles. Consumption of these tissues may provide human
with some needs from these important phytochemicals, though ingestion of livers, especially that of the sheep,
is not advisable for the pregnant women. 相似文献
16.
Niacin supplementation induces type II to type I muscle fiber transition in skeletal muscle of sheep
Muckta Khan Aline Couturier Johanna F Kubens Erika Most Frank-Christoph Mooren Karsten Krüger Robert Ringseis Klaus Eder 《Acta veterinaria Scandinavica》2013,55(1):85
Background
It was recently shown that niacin supplementation counteracts the obesity-induced muscle fiber transition from oxidative type I to glycolytic type II and increases the number of type I fibers in skeletal muscle of obese Zucker rats. These effects were likely mediated by the induction of key regulators of fiber transition, PPARδ (encoded by PPARD), PGC-1α (encoded by PPARGC1A) and PGC-1β (encoded by PPARGC1B), leading to type II to type I fiber transition and upregulation of genes involved in oxidative metabolism. The aim of the present study was to investigate whether niacin administration also influences fiber distribution and the metabolic phenotype of different muscles [M. longissimus dorsi (LD), M. semimembranosus (SM), M. semitendinosus (ST)] in sheep as a model for ruminants. For this purpose, 16 male, 11 wk old Rhoen sheep were randomly allocated to two groups of 8 sheep each administered either no (control group) or 1 g niacin per day (niacin group) for 4 wk.Results
After 4 wk, the percentage number of type I fibers in LD, SM and ST muscles was greater in the niacin group, whereas the percentage number of type II fibers was less in niacin group than in the control group (P < 0.05). The mRNA levels of PPARGC1A, PPARGC1B, and PPARD and the relative mRNA levels of genes involved in mitochondrial fatty acid uptake (CPT1B, SLC25A20), tricarboxylic acid cycle (SDHA), mitochondrial respiratory chain (COX5A, COX6A1), and angiogenesis (VEGFA) in LD, SM and ST muscles were greater (P < 0.05) or tended to be greater (P < 0.15) in the niacin group than in the control group.Conclusions
The study shows that niacin supplementation induces muscle fiber transition from type II to type I, and thereby an oxidative metabolic phenotype of skeletal muscle in sheep as a model for ruminants. The enhanced capacity of skeletal muscle to utilize fatty acids in ruminants might be particularly useful during metabolic states in which fatty acids are excessively mobilized from adipose tissue, such as during the early lactating period in high producing cows. 相似文献17.
Lentz LR Valberg SJ Herold LV Onan GW Mickelson JR Gallant EM 《American journal of veterinary research》2002,63(12):1724-1731
OBJECTIVE: To determine whether alterations in myoplasmic calcium regulation can be identified in muscle cell cultures (myotubes) and intact muscle fiber bundles derived from Thoroughbreds affected with recurrent exertional rhabdomyolysis (RER). ANIMALS: 6 related Thoroughbreds with RER and 8 clinically normal (control) Thoroughbred or crossbred horses. PROCEDURES: Myotube cell cultures were grown from satellite cells obtained from muscle biopsy specimens of RER-affected and control horses. Fura-2 fluorescence was used to measure resting myoplasmic calcium concentration as well as caffeine- and 4-chloro-m-cresol (4-CMC)-induced increases in myoplasmic calcium. In addition, intact intercostal muscle fiber bundles were prepared from both types of horses, and their sensitivities to caffeine- and 4-CMC-induced contractures were determined. RESULTS: Myotubes of RER-affected and control horses had identical resting myoplasmic calcium concentrations. Myotubes from RER-affected horses had significantly higher myoplasmic calcium concentrations than myotubes from control horses following the addition of > or = 2mM caffeine; however, there was no difference in their response to 4-CMC (> or = 1 mM). Caffeine contracture thresholds for RER and control intact muscle cell bundles (2 vs 10mM, respectively) were significantly different, but 4-CMC contracture thresholds of muscle bundles from RER-affected and control horses (500 microM) did not differ. CONCLUSIONS AND CLINICAL RELEVANCE: An increase in caffeine sensitivity of muscle cells derived from a family of related RER-affected horses was detected in vitro by use of cell culture with calcium imaging and by use of fiber bundle contractility techniques. An alteration in muscle cell calcium regulation is a primary factor in the cause of this heritable myopathy. 相似文献
18.
Robert J Posont Caitlin N Cadaret Joslyn K Beard Rebecca M Swanson Rachel L Gibbs Eileen S Marks-Nelson Jessica L Petersen Dustin T Yates 《Journal of animal science》2021,99(5)
Intrauterine stress impairs growth and metabolism in the fetus and offspring. We recently found that sustained maternofetal inflammation resulted in intrauterine growth-restricted (MI-IUGR) fetuses with asymmetric body composition, impaired muscle glucose metabolism, and β-cell dysfunction near term. These fetuses also exhibited heightened inflammatory tone, which we postulated was a fetal programming mechanism for the IUGR phenotype. Thus, the objective of this study was to determine whether poor growth and metabolism persisted in MI-IUGR lambs after birth. Polypay ewes received serial lipopolysaccharide or saline injections in the first 2 wk of the third trimester of pregnancy to produce MI-IUGR (n = 13) and control (n = 12) lambs, respectively. Lambs were catheterized at 25 d of age. β-Cell function was assessed at 29 d, hindlimb glucose metabolism at 30 d, and daily blood parameters from day 26 to 31. Glucose metabolism was also assessed in flexor digitorum superficialis (FDS) muscle isolated at necropsy on day 31. Asymmetric body composition persisted in MI-IUGR neonates, as these lambs were lighter (P < 0.05) than controls at birth and 31 d, but body and cannon bone lengths did not differ at either age. FDS muscles from MI-IUGR lambs were smaller (P < 0.05) and exhibited reduced (P < 0.05) glucose oxidation and Akt phosphorylation but similar glucose uptake compared with controls when incubated in basal or insulin-spiked media. Similarly, hindlimb glucose oxidation was reduced (P < 0.05) in MI-IUGR lambs under basal and hyperinsulinemic conditions, but hindlimb glucose utilization did not differ from controls. Circulating urea nitrogen and cholesterol were reduced (P < 0.05), and triglycerides, high-density lipoprotein cholesterol, and glucose-to-insulin ratios were increased (P < 0.05) in MI-IUGR lambs. Glucose and insulin concentrations did not differ between groups during basal or hyperglycemic conditions. Although circulating monocyte and granulocyte concentrations were greater (P < 0.05) in MI-IUGR lambs, plasma tumor necrosis factor α (TNFα) was reduced (P < 0.05). FDS muscle contained greater (P < 0.05) TNF receptor 1 (TNFR1) and IκBα protein content. These findings indicate that maternofetal inflammation in late pregnancy results in fetal programming that impairs growth capacity, muscle glucose oxidation, and lipid homeostasis in offspring. Inflammatory indicators measured in this study appear to reflect heightened cytokine sensitivity in muscle and compensatory systemic responses to it. 相似文献
19.
Young-Jo Song Woo-Jung Park Seul-Kee Lee Joong-Bok Lee Seung-Yong Park Chang-Seon Song Sang-Won Lee Kun-Ho Seo Young-Sun Kang Jae-Young Song In-Soo Choi 《Journal of veterinary science (Suw?n-si, Korea)》2014,15(4):575-578
Virus-like particles (VLPs) composed of the truncated capsid protein of swine hepatitis E virus (HEV) were developed and immune responses of mice immunized with the VLPs were evaluated. IgG titers specific for the capsid protein of swine HEV were significantly higher for all groups of mice immunized with the VLPs than those of the negative control mice. Splenocytes from mice immunized with the VLPs also produced significantly greater quantities of interferon (IFN)-γ than interleukin (IL)-4 and IL-10. These newly developed swine HEV VLPs have the capacity to induce antigen-specific antibody and IFN-γ production in immunized mice. 相似文献
20.
Plasma concentrations of oestradiol-17ß, progesterone, 15-keto–dihydro–PGF2α and luteinizing hormone (LH) were monitored in llamas and alpacas after mating with an intact male. Concentrations of LH and PGF2α metabolite were high immediately after copulation. Ovulation occurred in 92% of the animals. The first significant increases in progesterone were recorded on day 4 after mating. In non-pregnant animals the lifespan of the corpus luteum was estimated to be 8–9 days. Luteolysis occurred in association with the release of PGF2α. In pregnant animals, a transient decrease in progesterone concentrations was observed between days 8 and 18 in both species. No significant changes in PGF2α secretion were registered during this period. Oes– tradiol–17ß concentrations were high on the day of mating, declined to low values on day 4, and started to increase again on day 8. Peak values after luteolysis in non-pregnant animals were significantly higher than those registered in pregnant ones. Furthermore, concentrations of oestradiol-17ß were elevated for a longer period in non–pregnant than in pregnant animals. The results suggest that progesterone from the corpus luteum exerts a negative influence on follicular activity in pregnant animals by reducing oes– tradiol-17ß secretion. 相似文献