Programa de Pós-graduação em Ciências Fisiológicas - Multicêntrico
URI Permanente desta comunidade
Navegar
Navegando Programa de Pós-graduação em Ciências Fisiológicas - Multicêntrico por Por Orientador "Ferreira, Reginaldo Nassar"
Agora exibindo 1 - 3 de 3
Resultados por página
Opções de Ordenação
Item Avaliação do uso de aditivos aliados ao manejo alimentar no desenvolvimento do trato digestivo de bezerros(Universidade Federal de Goiás, 2021-04-14) Caixeta, Luis Fernando de Sousa; Custódio, Carlos Henrique Xavier; http://lattes.cnpq.br/0207928273284808; Ferreira, Reginaldo Nassar; http://lattes.cnpq.br/2555785079833283; Ferreira, Reginaldo Nassar; Biancardi, Manoel Francisco; Leão, Karen Martins; Mendes, Elizabeth Pereira; Moreira, Tainá SilvestreThis study examines the effect of restricted feeding, based on the amount of milk supplied, combined with the compensatory gain mechanism and supplementation with an essential amino acid (methionine analogue - MET) or essential oils (EO) on the intestinal development and intestinal health of calves. Twenty calves were weighed and subjected to four treatments (feeding regimes) for two 28-day periods, as follows: Treatment 1 (RES+MET) - restricted milk intake in the first period (3 L/animal/day) and no restriction in the second period (6 L/animal/day) plus 4 g MET/day in both periods; Treatment 2 (MET) - no milk restriction in either period (6 L/animal/day) plus 4 g MET/day in both periods; Treatment 3 (RES+EO - milk restriction in the first period (3 L/animal/day) and no restriction in the second period (6 L/animal/day) plus 1.5 g EO/day in both periods; and Treatment 4 (EO) - no milk restriction in either period (6 L/animal/day) plus 1.5 g EO/day in both periods. Weight change in period 1 was lower in the animals on RES+MET than in the MET group, and no difference was detected between the other groups. Total live weight change at the end of the experiment was similar between the groups. There were no differences between treatment groups and periods for serum lactate, alkaline phosphatase or creatinine levels. Total proteins differed between the periods in the RES+MET, RES+EO and EO groups. Rumen papillae height was lower in the restricted groups. The methionine analogue reduced morphological changes in the hepatocyte nucleus as a result of the nutritional mechanisms induced by compensatory gain. Intestinal integrity was maintained by the action of the methionine analogue. Essential oils enhance the expression of GHS-R1a receptors in the hypothalamus.Item Contribuição dos receptores de grelina dos neurônios pré-motores simpáticos do hipotálamo paraventricular para o controle da função cardiovascular(Universidade Federal de Goiás, 2018-05-09) Santana, Joice Simões; Custódio, Carlos Henrique Xavier; http://lattes.cnpq.br/0207928273284808; Ferreira, Reginaldo Nassar; http://lattes.cnpq.br/2555785079833283; Ferreira, Reginaldo Nassar; Custódio, Carlos Henrique Xavier; Ferreira, Patrícia Maria; Colugnati, Diego Basileon the balance of the excitatory and inhibitory synapses, such as gabaergic ones, is responsible for cardiovascular system modulation. The effects of ghrelin, a 28-amino acids peptide, are mediated by subtype 1a of the growth hormone secretagogue receptor (GHSR1a), densely expressed in the sympathetic pre-motor neurons of PVH. Therefore, this work investigated the effects of ghrelin on the control exercised by PVH on cardiovascular system and its relationship with gabaergic activity. For this purpose, mean systemic arterial pressure (PAM) in the femoral artery and pressure in the left cardiac ventricle (LVP) of Wistar rats (250-300 g) were measured by catheterization. Treatment with 100 nL of 0.03 nM ghrelin injected directly into PVH reduced PAM by 40 ± 12 mmHg and the maximum blood pressure in the left cardiac ventricle (LVPmax) by 28 ± 12 mmHg, as well as its derivative as a function of time (LVdP / dTmax), a measure of inotropism, which was reduced by 2051 ± 946 mmHg / s, without causing statistically significant changes in cardiac chronotropism. In contrast, to demonstrate that the effects of ghrelin were mediated by GHS-R1a, the inhibition of this receptor with 100 nL of PF04628935 (0.06 nM) in PVH caused an increase in PAM of 8 ± 3 mmHg and of LVPmax by 29 ± 8 mmHg; in addition to stimulating inotropism, with LVdP / dTmax being elevated at 1449 ± 467 mmHg / s, and chronotropism, with elevated heart rate at 29 ± 12 bpm. Finally, the comparison of its effects with muscimol, a GABAA receptor agonist, demonstrated that ghrelin potentiated the reduction in blood pressure induced by that drug, reducing PAM by 19 ± 5 mmHg, without significantly altering the pressure in the cardiac left ventricle and inotropism. Interestingly, ghrelin promoted na increase in heart rate by 27 ± 12 bpm, after muscimol injection. The present study demonstrated that the ghrelin axis - GHS-R1a in PVH contributes to cardiovascular control and related these effects to interactions with the gabaergic system.Item Papel da grelina e do receptor GHS-R1a no controle da função renal e hemodinâmica em animais normotensos e hipertensos(Universidade Federal de Goiás, 2019-03-14) Silva, Elder Sales da; Custódio, Carlos Henrique Xavier; http://lattes.cnpq.br/0207928273284808; Ferreira, Reginaldo Nassar; http://lattes.cnpq.br/2555785079833283; Custódio, Carlos Henrique Xavier; Ferreira, Patrícia Maria; Gomes, Rodrigo Mello; Gingozac, Marc Alexandre Duarte; Ferreira, Reginaldo NassarGhrelin (GRE) is a 28-amino acid peptide that depends on the acylation of serine at position 3 to act as a signaling molecule on growth hormone secretagogues (GHS-Rs). Its function depends on this interaction and these receptors are expressed in several tissues which may imply multisystemic actions. The objective of this research was to evaluate the responses related to renal and hemodynamic function in normotensive and hypertensive rats through administration of ghrelin and GHS-R1a agonists (MK0677) and antagonists (PF04628935). For this purpose, mice were used as experimental models being normotensive (WT) and spontaneously hypertensive (SHR). The following experimental designs were established: 1) Rats were injected subcutaneously (sc) vehicle (VEH) (NaCl 0,9%), ghrelin (GRE) (10μg / kg), GHS-R1a AT antagonist (PF04628935) (0.4mg / kg), ghrelin + PF0462893 or GHS-R1a agonist AGO (MK0677) (10μg / kg) and maintained in metabolic cages for further urinary and plasma analysis. 2- WT and SHR animals received intravenous (i.v.) injections of ghrelin (10 / kg), PF04628935 (0.4 mg / kg) or a combination of ghrelin and PF04628935 for vascular conductance record. 3 - GHS-R1a receptor expression was evaluated by Western blot in the aortic artery, renal artery, cortex and renal medulla. Metabolic parameters (renal function) revealed significant differences in relation to water and feed intake as well as urinary volumes in both the Wistar and SHR treated groups. The same was observed for free water and creatinine clearance in addition to osmolarity and urinary sodium and potassium levels. Intravenous injection of ghrelin reduced mean blood pressure in both strains without evoking significant chronotropic changes. Ghrelin increased Renal Vascular Conductivity (CVR) in SHR rats. The hypotensive and vasomotor effects (CVR) produced by ghrelin in SHR mice were reversed by the specific antagonism of GHS-R1a with PF04628935 (20 minutes after ghrelin injection), for all analyzes was determined (p <0.05). GHS-R1a receptor expression was shown to be decreased in the renal cortex of SHR animals. Thus, the data obtained suggest possible participation of ghrelin and GHR-S1a receptors in renal function and hemodynamic adjustments of normotensive and hypertensive rats.