Transforming growth factor-beta family members are regulated during induced luteolysis in cattle

The transforming growth factors beta (TGFβ) are local factors produced by ovarian cells which, after binding to their receptors, regulate follicular deviation and ovulation. However, their regulation and function during corpus luteum (CL) regression has been poorly investigated. The present study evaluated the mRNA regulation of some TGFβ family ligands and their receptors in the bovine CL during induced luteolysis in vivo. On day 10 of the estrous cycle, cows received an injection of prostaglandin F2α (PGF) and luteal samples were obtained from separate groups of cows (n= 4-5 cows per time-point) at 0, 2, 12, 24 or 48 h after treatment. Since TGF beta family comprises more than 30 ligands, we focused in some candidates genes such as activin receptors (ACVR-1A, -1B, -2A, -2B) AMH, AMHR2, BMPs (BMP-1, -2, -3, -4, -6 and -7), BMP receptors (BMPR 1A, -1B and -2), inhibin subunits (INH-A, -BA, -BB) and betaglycan (TGFBR3). The mRNA levels of BMP4, BMP6 and INHBA were higher at 2 h after PGF administration (P<0.05) in comparison to 0 h. The relative mRNA abundance of BMP1, BMP2, BMP3, BMP4, BMP6, ACVR1B, INHBA and INHBB was upregulated up to 12 h post PGF (P<0.05). On the other hand, TGFBR3 mRNA that codes for a reservoir of ligands that bind to TGF-beta receptors, was lower at 48 h. In conclusion, findings from this study demonstrated that genes encoding several TGFβ family members are expressed in a time-specific manner after PGF administration

Indução do parto de bovinos aos 270 dias de gestação com a utilização prévia de glicocorticoide de longa ação e a transferência de imunidade passiva - DOI: 10.4025/actascianimsci.v31i1.398

This experiment had the objective of evaluating passive immunity transfer and placental retention rates with the early use of a long-acting glucocorticoid to induce bovine parturition at 270 pregnancy days, as well as comparing protocol efficacy regarding the timing of parturition induction. Forty-two pregnant cows were selected from a beef and dairy herd and randomly assigned into one of three groups: control (C) without drug injection, but with the same management; long-acting + induction group (LA), with one injection of 30 mg prednisolone methylacetate, subcutaneous, on pregnancy day 255 and another injection of 20 mg dexamethasone plus 0.5 mg cloprostenol, intramuscular, on pregnancy day 270; induction group (I), with 20 mg dexamethasone plus 0.5 mg cloprostenol on pregnancy day 270. The early administration of long-acting glucocorticoid did not have any difference on passive immunity transfer and placental retention. Cows from groups LA and I calved in 41.36 ± 1.89 hours post-injection of 20 mg dexamethasone plus 0.5 mg cloprostenol, regardless of previous long-acting glucocorticoid administration on the LA group. Induction of parturition using dexamethasone and cloprostenol was efficient in all cows, regardless of previous prednisolone methylacetate administration.O trabalho teve por objetivo avaliar a taxa de transferência de imunidade passiva e de retenção de placenta com a utilização prévia de um glicocorticoide de longa ação na indução do parto bovino aos 270 dias de gestação, bem como verificar a eficácia dos protocolos. Foram utilizadas 42 vacas prenhes, de corte e de leite, aleatoriamente separadas em três grupos: Grupo-controle (C) que não recebeu aplicação hormonal, mas o mesmo manejo; Grupo longa ação + indução (LA) que recebeu 30 mg de acetato de metilprednisolona, via subcutânea, no dia 255 de gestação e 20 mg de dexametasona associada a 0,5 mg de cloprostenol sódico, via intramuscular, no dia 270 de gestação; e Grupo indução (I) que recebeu 20 mg de dexametasona associada a 0,5 mg de cloprostenol sódico no dia 270 de gestação. A utilização prévia do glicocorticoide de longa ação não mostrou diferença na taxa de transferência de imunidade passiva e nos índices de retenção de placenta. As fêmeas dos Grupos LA e I pariram em 41,36 ± 1,89h após a aplicação hormonal de dexametasona associada ao cloprostenol, independente de aplicação prévia de glicocorticoide de longa ação no Grupo LA. A indução da parição com dexametasona associada ao cloprostenol, independente da aplicação prévia de acetato de metilprednisolona, mostrou-se eficaz em todos dos animais

Grb10 characterization in bovine cumulus oocyte complexes from different follicle sizes

The objective of this study was to investigate the mRNA expression and protein localization of Grb10 gene in bovine cumulus-oocyte complexes (COCs) from different follicle sizes. Firstly, it was investigated the mRNA expression to correlate with maturation rates. COCs from follicles at 1-3, 4-6, 6-8 and &gt;8mm were used to evaluate Grb10 gene expression by qRT-PCR assay and nuclear maturation rates. It was observed that more competent oocytes (from follicles at 6-8 and &gt;8mm; P&gt;0.05), had lower Grb10 mRNA expression levels when compared to the oocytes from follicles at 1-3 and 4-6mm (P&gt;0.05). After it was performed an immunofluorescence analysis in COCs from different follicle sizes (1-3, 4-6, 6-8 and &gt;8mm) to investigate Grb10 protein localization. Samples were incubated with primary antibody: Polyclonal rabbit anti-Grb10 (1:100). Primary antibody was detected using goat anti-rabbit IgG antibody conjugated with Alexa Fluor 488 (1:500). Positive fluorescence signal was detected in all analyzed samples but less evident in COCs from largest follicles. These results characterized Grb10 gene in bovine COC and provide evidences for its involvement during oocyte molecular maturation

Expression of Ion Transporters and Na+/K+-ATPase and H+-ATPase Activities in the Gills and Kidney of Silver Catfish (Rhamdia quelen) Exposed to Different pHs

Exposure to acidic and alkaline pHs results in an ionic imbalance. Cellular responses involved in osmoregulation in silver catfish exposed to different pHs (5.5, 7.5, and 9.0) for 24 h were evaluated. The gills and kidney were collected to measure Na+/K+-ATPase (NKA) and H+-ATPase (V-ATPase) activities and to evaluate the expression of ion transporter-related genes: NKA (atp1a1), H+-ATPases (atp6v0a1b, atp6v0a2a, atp6v0a2b), Na+/H+ antiporter (slc9a3), K+/Cl&minus; symporters (slc12a4, slc12a6, slc12a7a, slc12a7b), Na+/K+/2Cl&minus; symporter (slc12a2), and ammonium transporter Rh type b (rhbg). The gills presented greater responses to pH changes than the kidney. The pH alterations changed the atp1a1 gene expression and NKA activity, whereas the H+-ATPase activity increased in the gills in alkaline water, probably to maintain ionic balance. The slc9a3 and slc12a2 genes play more prominent roles in the ion uptake at acidic pH than H+-ATPase. The slc12a7a was the only isoform of this transporter affected by pH. The rhbg is apparently related to ammonia excretion through the gills and kidney (minor scale). Exposure to alkaline pH seems to be battled by impairment of NKA and H+-ATPase activities in the gills, whereas the expression of some ion transporters in silver catfish changes during both acidic and alkaline pHs

Bone strength is reduced in a neonatal androgenized rat model

Background: Whether polycystic ovary syndrome (PCOS) affects bone health during a woman's lifespan remains controversial. An androgenized rodent model replicated many metabolic and reproductive features of women with PCOS, and we aimed to use it to investigate the impact of androgens on microarchitecture (by micro-CT), bone mechanical strength, bone formation and resorption markers in rats with intact ovaries (SHAM) who underwent oophorectomy. Methods: Wistar rats (Rattus norvegicus albinus) were employed for the experiments in this study. The protocol of androgenization consisted of the application of 1.25 mg s.c. testosterone propionate beteween days 2–5 of life, while the controls received the same amount of corn oil s.c. as previously established. Androgenized SHAM rats exhibited chronic anovulation identified by vaginal cytology and a reduction in the proportion of corpus luteum in the ovary in comparison to control SHAM rats. The realization of the ovariectomy or SHAM procedure occurred on Day 100 of life. All groups (n = 8) were followed-up for 180 days to address the study endpoints. Results: Micro-CT from androgenized female rats (SHAM) showed a divergence between the trabecular and cortical bone profiles. Compared to SHAM controls, these rats had an increase in trabecular bone mass with a diminution in bone resorption C-terminal telopeptide of type 1 collagen (CTX) (p < 0.05), a concomitant decrease in cortical area and thickness in the femur, and a reduction in the strength of the femur on the mechanical test (p < 0.01). Conclusions: Our results suggest that a reduction in the cortical thickness and cortical area observed in PCOS model rats was associated with a reduced strength of the femur, despite increased trabecular formation. Ovariectomy in the androgenized OVX group limited the progression rate of cortical bone loss, resulting in bone resistance and cortical thickness comparable to those observed in the control OVX group

Relationship between clinical and postmortem evaluation in repeat breeder beef cows Relação entre características clínicas e post-mortem em vacas de corte repetidoras de serviço

The objective of this study was to investigate the causes of the repeat breeder syndrome comparing clinical signs and postmortem findings in beef cows. The identification of factors affecting the reproductive tract can support decisions as to whether treatment of repeat breeder cows is justifiable than culling. Since all animals were submitted to clinical examination before being slaughtered, this study has a differential approach when compared with others, where genital tracts from abattoir were examined. In this study, 130 crossbred cows and heifers that have failed to conceive after three or more services were identified, submitted to a clinical examination and blood collection for karyotyping and sent to an abattoir. postmortem examinations included macroscopic evaluation of the genital tracts, bacteriology and histopathology of the uterus. Uterine alterations were predominant followed by oviduct and ovarian pathologies. Histopathological examination was more sensitive as a diagnostic tool than clinical examination. Repeat breeder cows had a predominance of uterine abnormalities (95%), such as inflammatory (42.9%) and degenerative (59.7%) conditions. Oviduct abnormalities were found in 29.8 % of animals. Furthermore, 1 out 10 karyotyped cows showed aneuploidy. Thus, this study stressed the importance of laboratory exams in the diagnosis of the causes of infertility of repeat breeder cows.<br>O objetivo deste estudo foi avaliar as causas de infertilidade em vacas de corte repetidoras de serviço, relacionando sinais clínicos com características laboratoriais post-mortem. A identificação dos fatores que afetam o desempenho reprodutivo pode fornecer uma fundamentação científica para auxiliar na decisão quanto ao destino de vacas repetidoras de serviço; tratamento ou descarte. Este estudo tem abordagem diferencial dos trabalhos que contemplam somente a ocorrência de alterações post-mortem do trato genital. A correlação das alterações post-mortem com o histórico clínico dos animais pode auxiliar na determinação da causa de repetição de serviço de animais sem alteração clínica. Foram utilizadas 130 vacas e novilhas cruzas que não conceberam depois de, no mínimo, três serviços. Todos os animais foram identificados e submetidos à exame clínico e coleta de sangue para cariotipagem. Foram incluídos no estudo apenas animais com histórico de falha reprodutiva. Os animais foram encaminhados para um abatedouro e foram realizados exames post-mortem como inspeção macroscópica do trato genital, cultura bacteriológica e estudo histopatológico do útero. Alterações uterinas foram predominantes seguidas de alterações de oviduto e ovário. Foi observada uma maior freqüência de alterações histopatológicas de útero que alterações clínicas. Os animais utilizados no estudo apresentaram alta freqüência de patologia uterina (95%), tanto inflamatórias (42,9%) quanto degenerativas (59,7%). Patologias diagnosticadas somente por exames post-mortem e laboratoriais como oclusão tubária (29,8%) e trissomia do par sexual também foram observadas (1/10 vacas). Portanto, este estudo evidencia a importância do exame laboratorial no diagnóstico das causas de infertilidade de vacas com histórico de repetição de serviço