Different levels of brain-derived neurotrophic factor and cortisol in healthy heavy smokers

Studies suggest that brain-derived neurotrophic factor (BDNF) and the hypothalamic-pituitary-adrenal (HPA) axis modulate dopaminergic activity in response to nicotine and that the concentrations of BDNF and cortisol seem to be dependent on the amount and duration of smoking. Therefore, we investigated BDNF and cortisol levels in smokers ranked by daily cigarette consumption. Twenty-seven adult males (13 non-smokers and 14 smokers) participated in the study. The smokers were divided in two groups: light (n=7) and heavy smokers (n=7). Anthropometric parameters and age were paired between the groups, and plasma BDNF and salivary cortisol levels were measured. Saliva samples were collected on awakening, 30 min after awakening, at 10:00 and 12:00 am, 5:00 and 10:00 pm. Additionally, cotinine serum levels were measured in smokers. Heavy smokers had higher mean values of BDNF compared to the control group (P=0.01), whereas no difference was observed in light smokers. Moreover, heavy smokers presented lower cortisol levels in the last collection (10:00 pm) than the control group (P=0.02) and presented statically higher values of cotinine than the light smokers (P=0.002). In conclusion, changes in BDNF and cortisol levels (10:00 pm) appear to be dependent on heavy cigarette smoking and can be involved in activation and in the relationship between the mesolimbic system and the HPA axis

Influência da heparina sódica na ocorrência de laminite eqüina induzida por sobrecarga de carboidratos

Avaliou-se a eficiência da infusão intravenosa de heparina sódica (100UI/kg/8h, a partir de 24h após o fornecimento de carboidrato, até completar 48h) no controle da laminite eqüina experimentalmente induzida por sobrecarga de carboidrato (17,6g de amido de milho/kg de peso corpóreo). Foram utilizados 15 eqüinos adultos, distribuídos em três grupos experimentais: GI (grupo-controle); GII (grupo laminite) e GIII (grupo laminite+heparina). Posteriormente ao fornecimento de carboidrato, os animais foram submetidos a exames físicos e laboratoriais durante um período de 48 horas. Ao final do experimento, os animais foram submetidos à eutanásia pela aplicação intravenosa de 5ml de maleato de acepromazina seguida de 1g de tiopental sódico e 1 litro de solução saturada de KCl para a obtenção de amostras de tecidos dos cascos, necessárias ao exame histológico. Os animais de GII e GIII, submetidos à sobrecarga de carboidratos, desenvolveram laminite, exibindo claudicação 12 e 24h após o fornecimento de carboidrato, respectivamente, bem como aumentos da freqüência cardíaca e do tempo de preenchimento capilar. As alterações histológicas, semelhantes em GII e GIII, eram do tipo degenerativo, como adelgaçamento de lâminas epidérmicas, retração, achatamento e deslocamento de lâminas dérmicas, vacuolização epidérmica e desorganização do tecido epidérmico. A infusão da heparina sódica não preveniu ou atenuou a degeneração laminar.The efficacy of intravenous heparin administration (100UI/kg/8h, from 24 to 48h after carbohydrate administration) in the control of carbohydrate overload-induced equine laminitis (17.6g of corn starch/kg live weight) was evaluated. Fifteen horses were allocated into three experimental groups: GI (control group), GII (laminitis group), and GIII (laminitis+heparin group). These animals were submitted to physical and laboratorial examination during 48h. After that time, they were euthanized with intravenous administration of 5ml of acepromazine followed by 1g of thiopental sodium and 1 liter of saturated solution of KCl to obtain hoof tissues samples for histological examination. GII and GIII horses developed laminitis, showing lameness 12 and 24h after carbohydrate administration, respectively, as well increased heart rate and capillary refill time. The histological alterations, similar in GII and GIII, were degenerative lesions, as thinness of epidermal lamina, retraction, flattening and dislocation of the dermal lamina, epidermal vacuolization, and disruption of the epidermal tissues. The occurrence of laminar degeneration was not prevented or attenuated with intravenous heparin administration.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP