RESUMO
Many cytokines have been proposed to regulate reproduction due to their actions on hypothalamic kisspeptin cells, the main modulators of gonadotropin-releasing hormone (GnRH) neurons. Hormones such as leptin, prolactin and growth hormone are good examples of cytokines that lead to Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway activation, consequently exerting effects in kisspeptin neurons. Different studies have investigated how specific components of the JAK/STAT signaling pathway affect the functions of kisspeptin cells, but the role of the suppressor of cytokine signaling 3 (SOCS3) in mediating cytokine actions in kisspeptin cells remains unknown. Cre-Loxp technology was used in the present study to ablate Socs3 expression in kisspeptin cells (Kiss1/Socs3-KO). Then, male and female control and Kiss1/Socs3-KO mice were evaluated for sexual maturation, energy homeostasis features, and fertility. It was found that hypothalamic Kiss1 mRNA expression is significantly downregulated in Kiss1/Socs3-KO mice. Despite reduced hypothalamic Kiss1 mRNA content, these mice did not present any sexual maturation or fertility impairments. Additionally, body weight gain, leptin sensitivity and glucose homeostasis were similar to control mice. Interestingly, Kiss1/Socs3-KO mice were partially protected against lipopolysaccharide (LPS)-induced body weight loss. Our results suggest that Socs3 ablation in kisspeptin cells partially prevents the sickness behavior induced by LPS, suggesting that kisspeptin cells can modulate energy metabolism in mice in certain situations.
Assuntos
Kisspeptinas , Lipopolissacarídeos , Animais , Peso Corporal/fisiologia , Citocinas/metabolismo , Feminino , Kisspeptinas/genética , Kisspeptinas/metabolismo , Leptina/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , RNA Mensageiro , Proteína 3 Supressora da Sinalização de Citocinas/genética , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Redução de PesoRESUMO
The effect of cactus (Opuntia ficus-indica) added to the diet of lactating (21 days of lactation) sows on voluntary feed intake, and its impact on the productive and reproductive post-weaning performance was evaluated. Data collected of 72 farrowings from 37 hybrid sows were analyzed during 12-month period. The sows were divided into two groups: (i) control group (CG; n = 18 sows), sows fed only with commercial feed, and (ii) experimental group (EG; n = 19 sows), sows fed with commercial feed plus cactus supplement. The variables evaluated were blood glucose (BG), daily feed intake (DFI) and total feed intake (TFI), loss of body weight (LBW), weaning-estrus interval (WEI), and subsequent litter size (SLS). Data analysis was carried out using fixed effects models. A nested effect was found for farrowing number (FN) into of group and an interaction group × season on the analyzed variables (P < 0.001). EG observed lower levels of BG with 47.0 ± 7.9 mg dL-1 pre-prandial and 56.1 ± 5.9 mg dL-1 post-prandial at the 10th day of lactation (P < 0.05). DFI and TFI were higher in the sows of the EG independently of the FN and season (P < 0.05). No differeces were observed on the nested effect of FN into group on the levels of BG (P < 0.05). Autumn showed the higher TFI: 121.4 kg-1 sow-1 (P < 0.05). Sows from CG 3rd farrowing and from EG 4th farrowing observed higher LBW (13.8 and 6.9%, respectively) (P < 0.05). Summer showed a higher LBW with 12.7% for CG and 8.2% for EG (P < 0.05). EG showed a lower WEI (5.5 days) and greater SLS up to 1.8 piglets more depending upon the season (P < 0.05). The lactating sow's diet supplemented with cactus can counterbalance the negative effects of lactational hypophagia due to reduction on levels of BG during lactation and an increase on DFI and, therefore, improves performance of LBW, WEI, and SLS.
Assuntos
Ração Animal/análise , Dieta/veterinária , Lactação/fisiologia , Opuntia , Suínos/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Ingestão de Alimentos/fisiologia , Estro/efeitos dos fármacos , Feminino , Gravidez , Distribuição Aleatória , Reprodução/efeitos dos fármacosRESUMO
The effect of spineless cactus intake (Opuntia ficus-indica) on blood glucose (BG) levels in lactating sows and its impact on daily and total feed intake (dFI-1 and TFI, respectively), body weight loss (BWL), and weaning-estrus interval length (WEI) were evaluated. Thirty-four hybrid (Yorkshire × Landrace × Pietrain) sows in lactation phase were used. Sows were divided into two groups: G1 (n = 17) where they received commercial feed and G2 (n = 17) provided with commercial feed plus an average of 2.0 ± 0.5 kg spineless cactus, based on a sow's body weight. The variables evaluated were BG, dFI-1, TFI, BWL, and WEI. Statistical analysis was performed by using a fixed and mixed model methodology, under a repeated measurements experiment. Group effects were found on all analyzed variables (P < 0.05). The BG was lower in G2 (55.2 and 64.5 mg/dL pre- and post-prandial, respectively), compared to that in G1 (70.9 and 80.1 mg/dL pre- and post-prandial, respectively) (P < 0.05). G2 showed better performance than G1 for dFI-1, BWL, and WEI (P < 0.05) whose averages were 5.5 ± 1.8 kg, 7.4 ± 4.5%, and 5.3 ± 1.2 days, respectively. Averages for these variables in G1 were 4.7 ± 1.5 kg, 16.8 ± 4.6%, and 6.1 ± 1.6 days, respectively. Intake of spineless cactus reduced BG levels in lactating sows, generating greater dFI-1, lower BWL at the end of lactation, and a lower WEI.