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1.
Res Vet Sci ; 158: 50-55, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36924635

RESUMO

Beef cattle welfare and health status are influenced by housing and management systems. The present study aimed to assess the welfare and health status in the first 15 days after arrival of Limousine bulls imported from France and fattened in a commercial fattening unit in Italy. A total of 264 bulls were included in the study. Welfare, biosecurity, and major hazard and warning system were assessed on days 2 (T1) and 15 (T2) after arrival to the unit. At T1 and T2 an inspective clinical examination was performed on all bulls. At T1 and T2 blood samples were collected from 88 bulls for haematological analysis. Both at T1 and T2, the welfare, biosecurity, and major hazards and warning systems were classified with a general score of medium but with a decrease on animal-based measurements in T2. At T1 and T2 the clinical examination revealed a significant increase (p-value≤0.05) of skin lesions and lameness in T2. A high incidence of respiratory disease was noticed in both assessed times. Leucocytes and all differentials count, and platelets were significantly increased (p-value≤0.05) at T2, while the fibrinogen was significantly decreased. The haematological changes suggest that the bulls were under higher stress in T2 when compared with T1 linked with a difficult adaptation response to the fattening unit. A multi-factorial approach that integrates the indicators of the checklist and the clinical and haematological findings of animals can be a useful method to deepen the assessment of welfare in beef cattle.


Assuntos
Doenças dos Bovinos , Doenças Respiratórias , Animais , Bovinos , Masculino , França/epidemiologia , Itália/epidemiologia , Abrigo para Animais , Doenças Respiratórias/veterinária , Incidência , Bem-Estar do Animal , Doenças dos Bovinos/epidemiologia
2.
Animal ; 15(1): 100071, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33516029

RESUMO

The use of electronic devices to improve animal health, welfare and farm efficiency in precision livestock farming is a developing area of great scientific and commercial interest. In particular, the use of on-site dairy farm instruments to detect calving is a tool in reproduction livestock farming. The primary aim of this study was to validate the ability of the Moocall device (MD) to detect calving cows. In addition, behavioural changes in parturient dairy cows were evaluated using video-based observations. The MD was applied approximately 9 days before cow delivery. Observational sessions were conducted three times a day for each cow from the day before MD application to calving time. The sensitivity (Se) and specificity (Sp) at 3 and 24 h before calving were measured to test the effectiveness of the MD. In addition, behavioural changes were investigated before and after the MD application as well as before and during calving time. The 3 h Se and the 3 h Sp obtained were 95.2 and 71.4%, respectively. No false negatives were observed in the 24 h before delivery (24 h Se=100%) while the 3 h Se was 95.2%. The MD was well tolerated by the dairy cows since no change in behaviours was observed in this study among the cows with or without the MD, except for an increase in eating behaviour in the animals with the MD. As regards, the behavioural pattern during calving time (8 h before calving) in comparison with the previous phases, a significant increase in tail contraction frequency and raised tail position, and a decrease in eating behaviour and rumination time were observed. The first principal component (PC) was primarily explained by these variables, and calving cows best contributed to this PC. According to the results of the present study, the use of the MD can be a useful tool in detecting the moment of calving.


Assuntos
Doenças dos Bovinos , Parto , Animais , Bovinos , Fazendas , Comportamento Alimentar , Feminino , Lactação , Gravidez , Cauda
3.
Heliyon ; 6(1): e03311, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32021942

RESUMO

Accompanying human beings since the Paleolithic period, dogs has been recently regarded as a reliable model for the study of the gut microbiome connections with health and disease. In order to provide some glimpses on the connections between the gut microbiome layout and host behavior, we profiled the phylogenetic composition and structure of the canine gut microbiome of dogs with aggressive (n = 11), phobic (n = 13) and normal behavior (n = 18). Hormones' determination was made through Radio Immuno-Assay (RIA), and next generation sequencing of the V3-V4 gene region of the bacterial 16S rRNA was employed to determine gut microbiome composition. Our results did not evidence any significant differences of hormonal levels between the three groups. According to our findings, aggressive behavioral disorder was found to be characterized by a peculiar gut microbiome structure, with high biodiversity and enrichment in generally subdominant bacterial genera (i.e. Catenibacterium and Megamonas). On the other hand, phobic dogs were enriched in Lactobacillus, a bacterial genus with known probiotic and psychobiotic properties. Although further studies are needed to validate our findings, our work supports the intriguing opportunity that different behavioral phenotypes in dogs may be associated with peculiar gut microbiome layouts, suggesting possible connections between the gut microbiome and the central nervous system and indicating the possible adoption of probiotic interventions aimed at restoring a balanced host-symbiont interplay for mitigating behavioral disorders.

4.
J Integr Neurosci ; 16(s1): S3-S11, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29154287

RESUMO

Consciousness is the greatest enigma in human history. For centuries scientists and researchers have tried to describe it without coming to conclusions. In the last years with the neurosciences development, consciousness has become the common goal of numerous studies. But consciousness has always been studied only in humans, but after "Cambridge Declaration on Consciousness" in 2012, even non-human animalsthey feel possessed of the consciousness. According to "theory Orch-OR" of Hameroff and Penrose we have conducted a study on Alaskan malamute and German shepherd to analysed a triplet of platelet fatty acids (linoleic acid; palmitic acid; arachidonic acid). Through these analysis and the relative mapping of subjects within a SOM it was possible to make an assessment of the possible onset of mood disorders in the dogs. A critical analysis of the results obtained shows that animals have molecular analogies with humans compared to mood disorders. The German shepherd and Alaskan malamute, indeed, have, in the case of major depression, a bio-chemical profile, the most similar to man.


Assuntos
Estado de Consciência/fisiologia , Animais , Humanos , Transtornos do Humor/metabolismo
5.
J Dairy Sci ; 100(1): 620-628, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27837985

RESUMO

Stressful situations trigger several changes such as the secretion of cortisol and dehydroepiandrosterone (DHEA) from the adrenal cortex, in response to ACTH. The aim of this study was to verify whether overstocking during the dry period (from 21±3 d to the expected calving until calving) affects DHEA and cortisol secretion and behavior in Holstein Friesian cows. Twenty-eight cows were randomly divided into 2 groups (14 animals each), balanced for the number of lactations, body condition score, and expected date of calving. Cows in the far-off phase of the dry period (from 60 to 21 d before the expected calving date) were housed together in a bedded pack. Then, animals from 21±3 d before the expected calving until calving were housed in pens with the same size but under different crowding conditions due to the introduction of heifers (interference animals) into the pen. The control condition (CTR) had 2 animals per pen with 12.0m2 each, whereas the overstocked condition (OS) had 3 interference animals in the same pen with 4.8m2 for each animal. On d -30±3, -21±3, -15±3, -10±3, and -5±3 before and 10, 20, and 30 after calving, blood samples were collected from each cow for the determination of plasma DHEA and cortisol concentrations by RIA. Rumination time (min/d), activity (steps/h), lying time (min/d), and lying bouts (bouts/d) were individually recorded daily. In both groups, DHEA increased before calving and the concentration declined rapidly after parturition. Overstocking significantly increased DHEA concentration compared with the CTR group at d -10 (1.79±0.09 vs. 1.24±0.14 pmol/mL), whereas an increase of cortisol was observed at d -15 (3.64±0.52 vs. 1.64±0.46ng/mL). The OS group showed significantly higher activity (steps/h) compared with the CTR group. Daily lying bouts tended to be higher for the OS group compared with CTR group in the first week of treatment. The overall results of this study documented that overstocking during the dry period was associated with a short-term changes in DHEA and cortisol but these hormonal modifications did not influence cow behavior.


Assuntos
Desidroepiandrosterona , Hidrocortisona , Animais , Bovinos , Parto Obstétrico , Feminino , Lactação , Parto
6.
Res Vet Sci ; 95(3): 1076-80, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23962857

RESUMO

The purpose of this work was to perform a preliminary screening in the domestic cat to assess the concentration of cortisol in hairs by radioimmunoassay technique (RIA) in presence or absence of Microsporum canis infections. A total of 245 cats (7 with cutaneous lesions referable to dermatophytosis and 238 apparently healthy) coming from 14 shelters were examined. M. canis was isolated in 126 (51.4%) cats. The cortisol levels were significantly higher in cats with lesions or without lesions but with a high number of colonies in the plates (≥ 10 CFU) than in cats negative or with a lower number of colonies. The results obtained seem to highlight that chronic high levels of cortisol in cats could possibly promote the dermatophytes infections. Furthermore, in High-CFU asymptomatic cats, it could be present a state of infectious, and they, therefore, represents not a simple mechanical carrier.


Assuntos
Doenças do Gato/microbiologia , Dermatomicoses/veterinária , Cabelo/química , Hidrocortisona/análise , Microsporum , Animais , Doenças do Gato/metabolismo , Gatos , Dermatomicoses/metabolismo , Feminino , Masculino , Radioimunoensaio/veterinária
7.
J Vet Intern Med ; 27(5): 1268-72, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23869438

RESUMO

BACKGROUND: Measurement of hair cortisol is a noninvasive technique used for several purposes in humans and in animals. OBJECTIVES: To measure hair cortisol concentrations (HCC) in dogs with spontaneous hypercortisolism (HC) and determine whether it can represent a useful diagnostic test for this syndrome. ANIMALS: Twenty-two dogs with spontaneous HC before treatment, 28 sick control dogs (SCD), and 40 healthy dogs. METHODS: In this prospective, observational clinical study, the HCC was measured by an RIA assay after extraction in HC dogs, in dogs with other chronic diseases, and in healthy dogs. The diagnostic accuracy of HCC was evaluated by subjecting data from dogs with HC and dogs with other chronic diseases to receiver operating characteristic (ROC) curve analysis. RESULTS: Median (range) cortisol concentration in dogs with HC was 4.53 pg/mg (0.32-74.62 pg/mg) and was significantly higher than in SCD (1.49 pg/mg, 0.13-14.19 pg/mg) and healthy dogs (1.28 pg/mg, 0.34-5.38 pg/mg). Within the 3 groups, there was a large overlap of HCC. The area under the ROC curve was 0.80 (95% CI: 0.67-0.92). A cut-off value of HCC of 1.93 pg/mg revealed 91% sensitivity and 61% specificity to diagnose HC. CONCLUSIONS AND CLINICAL IMPORTANCE: Hair cortisol concentrations are higher in dogs with HC compared to SCD and healthy dogs. It is a noninvasive technique that should be further investigated as a possible diagnostic procedure for the diagnosis of HC in dogs.


Assuntos
Síndrome de Cushing/veterinária , Doenças do Cão/diagnóstico , Cabelo/química , Hidrocortisona/química , Animais , Síndrome de Cushing/diagnóstico , Doenças do Cão/metabolismo , Cães , Feminino , Hidrocortisona/metabolismo , Masculino
8.
J Dairy Sci ; 90(4): 1683-91, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17369208

RESUMO

Leptin is an important hormone regulating nutritional status in humans and animals. Its most relevant activity is at the hypothalamic level, where it modulates food behavior, thermogenesis, and secretion of several pituitary hormones. The exact mechanisms underlying these processes are unclear. The purpose of this study was to verify whether leptin could modulate growth hormone (GH) and prolactin (PRL) secretion acting directly on bovine pituitary cells. Adenohypophyseal explants were cultured with different concentrations of leptin (50, 250, and 500 ng/mL); GH and PRL concentrations in culture media were determined by RIA. On tissues treated with 250 ng/mL of leptin, GH and PRL mRNA, as well as protein content, were estimated by reverse transcription-PCR and Western immunoblotting, respectively. Concentrations of GH in culture media containing 250 and 500 ng/mL of leptin were significantly higher than in controls: 1,063.5 +/- 141.2 (mean +/- SEM) and 1,018.8 +/- 88.4 vs. 748.9 +/- 74.0 ng/mg of tissue, respectively, after 1 h of treatment. Prolactin concentrations were significantly higher in culture media containing 50, 250, and 500 ng/mL of leptin than in controls after 2 h of treatment (547.1 +/- 50.3, 547.5 +/- 58.8, and 577.0 +/- 63.7 vs. 406.8 +/- 43.9 ng/mg of tissue, respectively). Tissues cultured with 250 ng/mL of leptin had significantly higher GH mRNA and lower GH protein content than controls (389.7 +/- 17.9 vs. 289.7 +/- 16.7; 1,601.5 +/- 90.1 vs. 2,212.7 +/- 55.6 arbitrary units, respectively) after 5 h of treatment. In contrast, no significant differences were found for PRL mRNA and protein content, possibly because of a delay in the leptin stimulation of PRL secretion. The results suggest that GH and PRL secretion in bovine pituitary explants can be directly regulated by leptin.


Assuntos
Bovinos/metabolismo , Hormônio do Crescimento/metabolismo , Leptina/farmacologia , Leptina/fisiologia , Adeno-Hipófise/efeitos dos fármacos , Prolactina/metabolismo , Animais , Células Cultivadas , Meios de Cultura/análise , Regulação da Expressão Gênica/efeitos dos fármacos , Hormônio do Crescimento/genética , Masculino , Adeno-Hipófise/citologia , Adeno-Hipófise/metabolismo , Prolactina/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária
9.
J Dairy Sci ; 89(12): 4678-86, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17106100

RESUMO

Leptin is mainly secreted by adipocytes and is implicated in the regulation of metabolic status, feed intake, and body condition. Day length (DL) can affect leptin gene expression and secretion. The aim of the study was to evaluate the effect of DL on gene expression of leptin and leptin receptors in adipose tissue (AT). Four lactating and pregnant Holstein cows were housed in a climate-controlled chamber for 51 d. The first 30 d were used to adapt animals to the new housing conditions. During that period the DL adopted was 12 h light:12 h dark (12:12). The experimental period included 3 different and consecutive phases: 7 d of neutral DL (12:12); 7 d of long DL (18 h light:6 h dark); and 7 d of short DL (6 h light:18 h dark). Subcutaneous AT biopsies were performed at the end of each phase. Prolactin, growth hormone, cortisol, leptin, glucose, nonesterified fatty acids, beta-OH-butyrate, and cholesterol were determined in plasma samples. Abundance of leptin mRNA, and Ob-Ra and Ob-Rb leptin receptor mRNA were determined in AT samples by ribonuclease protection assay. Day length did not affect feed intake or body condition score. Exposure to short DL significantly reduced milk yield (13.1 +/- 2.2 vs. 15.8 +/- 1.7 and 16.0 +/- 2.0 kg/d for short vs. neutral and long DL, respectively). Plasma leptin, growth hormone, cortisol, nonesterified fatty acids, beta-OH-butyrate, and glucose were not affected by DL; cholesterol was lowest under short DL (3.93 +/- 0.38 vs. 4.36 +/- 0.39 and 4.07 +/- 0.38 mmol/L for short vs. neutral and long DL, respectively). Prolactin increased under long DL (134.82 +/- 16.94 vs. 81.98 +/- 20.25 and 96.16 +/- 0.38 ng/mL for long vs. neutral and short DL, respectively). Gene expression of leptin and its receptors was affected by DL. Leptin mRNA increased under long DL (11.91 +/- 0.84 vs. 7.82 +/- 0.84 and 7.56 +/- 0.84 pg of mRNA/microg of total RNA for long vs. neutral and short DL, respectively). Leptin receptors Ob-Ra and Ob-Rb mRNA were higher under long DL, whereas Ob-Ra and Ob-Rb mRNA were lower under short DL (Ob-Ra: 1.91 +/- 0.41, 2.49 +/- 0.41, and 0.65 +/- 0.41 pg of mRNA/microg of total RNA for neutral, long, and short DL, respectively; Ob-Rb: 5.29 +/- 0.79, 5.98 +/- 0.68, and 2.02 +/- 0.70 pg of mRNA/microg of total RNA for neutral, long, and short DL, respectively). Results of the present study appear to exclude an effect of feed intake and metabolic status on leptin gene expression. A prolactin-mediated effect of photoperiod on AT leptin modulation may be proposed in lactating dairy cows.


Assuntos
Tecido Adiposo/fisiologia , Bovinos/fisiologia , Regulação da Expressão Gênica/fisiologia , Leptina/biossíntese , Fotoperíodo , Receptores para Leptina/biossíntese , Tecido Adiposo/química , Ração Animal/análise , Animais , Primers do DNA/química , Feminino , Gliceraldeído-3-Fosfato Desidrogenases/análise , Lactação/fisiologia , Leptina/análise , Reação em Cadeia da Polimerase/veterinária , Gravidez , Prolactina/sangue , Receptores para Leptina/análise , Fatores de Tempo
10.
Tissue Eng ; 11(5-6): 709-14, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15998212

RESUMO

Granulosa cells from bovine and porcine ovaries were cultured either in monolayer or in follicle-like barium alginate capsules for 6 days. Morphological investigation by electron scanning microscopy indicated that culture in a three-dimensional (3D) system allows self-organization of spherical-polyhedral shape cells. The luteinization index (progesterone:17beta-estradiol ratio) was significantly higher for monolayer cells than for the 3D cell culture system, confirming the results of morphological analysis and indicating more physiological growth. The encapsulated 3D culture system appears to be a promising way of obtaining in vitro maturation and development of follicles and oocytes.


Assuntos
Células da Granulosa , Membranas Artificiais , Modelos Biológicos , Engenharia Tecidual , Alginatos , Animais , Bovinos , Técnicas de Cultura de Células , Feminino , Ácido Glucurônico , Ácidos Hexurônicos , Microscopia Eletrônica de Varredura , Oócitos , Protaminas , Suínos , Fatores de Tempo
11.
Domest Anim Endocrinol ; 29(2): 274-82, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15998501

RESUMO

We have demonstrated that insulin-like growth factor binding protein-5 (IGFBP-5) production by mammary epithelial cells increases dramatically during forced involution of the mammary gland in rats, mice and pigs. We proposed that growth hormone (GH) increases the survival factor IGF-I, whilst prolactin (PRL) enhances the effects of GH by decreasing the concentration of IGFBP-5, which would otherwise inhibit the actions of IGFs. To demonstrate a causal relationship between IGFBP-5 and cell death, we created transgenic mice expressing IGFBP-5, specifically, in the mammary gland. DNA content in the mammary glands of transgenic mice was decreased as early as day 10 of pregnancy. Mammary cell number and milk synthesis were both decreased by approximately 50% during the first 10 days of lactation. The concentrations of the pro-apoptotic molecule caspase-3 was increased in transgenic animals whilst the concentrations of two pro-survival molecules Bcl-2 and Bcl-x were both decreased. In order to examine whether IGFBP-5 acts by inhibiting the survival effect of IGF-I, we examined IGF receptor- and Akt-phoshorylation and showed that both were inhibited. These studies also indicated that the effects of IGFBP-5 could be mediated in part by IGF-independent effects involving potential interactions with components of the extracellular matrix involved in tissue remodeling, such as components of the plasminogen system, and the matrix metallo-proteinases (MMPs). Mammary development was normalised in transgenic mice by R3-IGF-I, an analogue of IGF-I which binds weakly to IGFBPs, although milk production was only partially restored. In contrast, treatment with prolactin was able to inhibit early involutionary processes in normal mice but was unable to prevent this in mice over-expressing IGFBP-5, although it was able to inhibit activation of MMPs. Thus, IGFBP-5 can simultaneously inhibit IGF action and activate the plasminogen system thereby coordinating cell death and tissue remodeling processes. The ability to separate these properties, using mutant IGFBPs, is currently under investigation.


Assuntos
Morte Celular/fisiologia , Matriz Extracelular/fisiologia , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/fisiologia , Glândulas Mamárias Animais/citologia , Animais , Sobrevivência Celular/fisiologia , Feminino , Hormônio do Crescimento/fisiologia , Fator de Crescimento Insulin-Like I/fisiologia , Neoplasias/etiologia , Prolactina/fisiologia
12.
Reprod Domest Anim ; 40(3): 217-23, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15943695

RESUMO

Leptin may play a role in the endocrine-metabolic processes that guarantee the physiological course of lactation in dairy cattle. This study was aimed at determining the changes in plasma concentrations of leptin and some of the main hormones and metabolites involved in the lactogenetic process in high-yielding dairy cows throughout lactation; we also wanted to assess whether leptin secretion is subjected to seasonal influences. Blood samples were collected from 23 Italian Friesian dairy cows from the end of a lactation to the ninth month of the subsequent one; in addition, blood was sampled from 47 dairy cows in different phases of lactation during February and July. Plasma concentrations of leptin, growth hormone (GH), insulin, prolactin (PRL), glucose, non-esterified fatty acids (NEFA) and urea were quantified by either validated radioimmunoassay (RIA) or enzymatic colorimetric methods. At the beginning of lactation, GH concentrations significantly increased, while a significant reduction occurred in leptin and insulin. This endocrine condition, such as the significant increase in NEFA plasma concentrations, is indicative of a marked lipid mobilization. In the more advanced stages of lactation, when both energy and protein balances become positive, leptin plasma concentrations increased, whereas GH and NEFA concentrations declined. During the summer months, a significant increase in leptin plasma concentrations, irrespective of the phase of lactation, was observed. Collectively, our findings suggest that, in dairy cows, leptin may represent a 'metabolic signal' of animal's status of fattening and nutritional level; in addition, leptin seems to be influenced by photoperiod and environmental temperature.


Assuntos
Bovinos/sangue , Hormônio do Crescimento/sangue , Insulina/sangue , Lactação/fisiologia , Leptina/sangue , Prolactina/sangue , Fenômenos Fisiológicos da Nutrição Animal , Animais , Glicemia/análise , Metabolismo Energético , Ácidos Graxos não Esterificados/sangue , Feminino , Fotoperíodo , Proteínas/metabolismo , Estações do Ano , Temperatura , Fatores de Tempo , Ureia/sangue
13.
J Physiol Pharmacol ; 56(4): 689-98, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16391424

RESUMO

Leptin, a protein produced and secreted by adipocytes, is know to regulate food intake and whole-body energy metabolism, but knowledge about its possible effect in bovine mammary gland is scarce. Leptin may be involved in the regulation of glucose transport even though this effect at the tissue level remains controversial. Once uptaken by the mammary gland, glucose is utilised in several ways but the majority, about 60-70%, is drained for lactose synthesis. This study was aimed at investigating the effect of leptin on glucose regulation in bovine mammary gland. We have examined the effects of leptin on the expression of GLUT1 mRNA, pyruvate kinase (PK) as well as glucose-6-phosphate dehydrogenase (G6PDH) activity. Treatment of mammary gland explants with recombinant leptin did not influence glucose assimilation, pathway transport (GLUT1 mRNA) and glucose metabolism (PK and G6PDH) in this tissue. The results from this study seem to exclude an involvement of leptin in glucose uptake and metabolism in bovine mammary gland.


Assuntos
Glucose/metabolismo , Leptina/farmacologia , Glândulas Mamárias Animais/metabolismo , Animais , Bovinos , Feminino , Glândulas Mamárias Animais/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Técnicas de Cultura de Tecidos
14.
J Dairy Sci ; 86(1): 152-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12613860

RESUMO

To investigate the correlation between lactation and thyroid hormone metabolism, the authors studied concentrations of total and free thyroxine (T4 and fT4), triiodothyronine (T3 and fT3), and reverse triiodothyronine (rT3) in plasma and milk, as well as liver and mammary gland 5'-deiodinase (5'D) activity in dry, early, middle, and late lactating dairy cows. Cows in early lactation show lower plasma levels of T4 and rT3 than dry, middle, and late lactating animals, whereas T3 shows the lowest plasma levels in the dry period; free T4 and T3 show a similar pattern. In early lactation there is a clear decrease in liver 5'D associated with a notable increase in mammary 5'D. Concentrations of T4 and T3 in milk drop significantly in the first few days after delivery, whereas rT3 increases up to the fourth month. The findings suggest a relationship between the hypothyroid status of lactating cows and the rearrangement of organ-specific 5'-deiodinase activity related to the maintenance of the udder's function.


Assuntos
Bovinos/fisiologia , Iodeto Peroxidase/metabolismo , Lactação/metabolismo , Fígado/enzimologia , Glândulas Mamárias Animais/enzimologia , Tironinas/sangue , Animais , Bovinos/metabolismo , Feminino , Leite/química , Radioimunoensaio/veterinária , Tironinas/análise , Tri-Iodotironina/análise , Tri-Iodotironina/sangue , Tri-Iodotironina Reversa/análise , Tri-Iodotironina Reversa/sangue
15.
J Dairy Sci ; 85(3): 507-13, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11949853

RESUMO

Bovine mammary involution, an important process for subsequent lactations, is characterized by loss of epithelial cells by apoptosis, but its hormonal regulation is still not well defined. Prolactin (PRL) and growth hormone (GH) play a specific role on rat mammary gland apoptosis, through insulin-like growth factor 1 (IGF-1) and the IGF binding protein (IGFBP) system. The purpose of our investigation was to determine the possible role of PRL, GH, and IGF-1 on cell survival and on IGFBP-5 expression in the bovine mammary gland. Mammary gland explants were cultured in the presence of cortisol, 17beta-estradiol, progesterone, insulin, PRL, GH, and IGF-1 and with the same treatment but without PRL, GH or IGF-1, respectively. After 24 h of culture, we determined the level of apoptosis through evaluation of DNA laddering in the oligonucleosomal fraction and examined IGFBP-5 messenger RNA (mRNA) expression. The results show a high level of DNA laddering and an increase in IGFBP-5 mRNA content in mammary explants cultured in the absence of PRL, GH, or IGF-I with respect to explants treated with all hormones. Moreover, explants cultured in presence of PRL, GH, or IGF-I show a low level of DNA laddering and IGFBP-5 expression with respect to explants cultured without any hormones. These data demonstrate a relationship between levels of apoptosis and IGFBP-5 mRNA expression in the bovine mammary gland and confirm the involvement of this binding protein programmed cell death and its relationship with the main lactogenic hormones.


Assuntos
Apoptose/fisiologia , Bovinos/fisiologia , Hormônio do Crescimento/fisiologia , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Fator de Crescimento Insulin-Like I/fisiologia , Prolactina/fisiologia , Animais , Apoptose/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Fragmentação do DNA , Células Epiteliais , Feminino , Regulação da Expressão Gênica , Lactação/fisiologia , Glândulas Mamárias Animais/citologia , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária
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