ABSTRACT Objective To determine whether passive smoking causes morphological and structural changes in the arcuate arteries of rats exposed for 7 to 28 days. Methods Wistar rats aged eight weeks and weighing 260g on average were allocated to a Control or a Smoker Group. Groups were further divided into 4 groups containing 5 animals each. Morphological-functional analysis of the right kidneys was carried out after 7 and 28 days of exposure to the smoke of 40 cigarettes per day. Cigarettes were burned at set times using automated cigarette-burning equipment (“Smoking Machine” - SM-MC-01). At the end of each exposure period, the kidneys were dissected and submitted to histological processing for morphological and quantitative analysis. Results Exposure to cigarette smoke for 7 days led to a decrease in inner vascular diameter. Decreased thickness of the vascular tunica media was observed after exposure for 28 days. Increased thickness of the tunica adventitia, increased total vascular wall thickness, increased total vascular diameter and qualitative increase in collagen deposition were observed. Vascular volume increased after 28 days of exposure. Conclusion Passive smoking has a negative impact on renal vasculature.

RESUMO Objetivo Analisar se a inalação passiva da fumaça do cigarro proporciona alterações morfológicas, estruturais e funcionais nos rins de ratos. Métodos Ratos Wistar, com oito semanas de idade, pesando, em média, 260g, foram divididos em Grupo Controle e Grupo Tabagista. Cada grupo foi subdividido em quatro grupos de dez animais para análise morfofuncional, em um período de sete e 28 dias. O Grupo Tabagista foi exposto à fumaça de 40 cigarros por dia, em horários determinados e equipamento automatizado de queima de cigarros, denominado smoking machine (SM-MC-01). Após o período de exposição, foram coletadas amostras de urina e sangue para as análises funcionais, e os rins foram dissecados e submetidos a procedimentos histológicos para análises morfoquantitativas. Resultados Após a exposição dos animais do Grupo Tabagista, observou-se menor ganho de peso; menor consumo de água e ração; menor peso, diâmetro e volume renal; redução em espessura cortical e densidade de volume glomerular; diminuição no diâmetro glomerular e capsular; aumento na densidade mesangial; volume urinário diminuído; níveis aumentados de glicose, creatinina sérica e microalbuminúria; níveis reduzidos de creatinina urinária e redução da taxa de depuração da creatinina. Conclusão O tabagismo passivo influencia negativamente na morfologia renal e na taxa de filtração glomerular, com efeitos semelhantes aos descritos na literatura em relação ao tabagismo ativo.

ABSTRACT Objective To analyze whether passive inhalation of cigarette smoke causes morphological, structural, and functional changes in kidneys of rats. Methods Wistar rats, aged eight weeks, weighing on average 260g, were divided into Control Group and Smoking Group. Each group was subdivided into four groups of ten animals for morphofunctional analysis, in a period of seven and 28 days. The Smoking Group was exposed to smoke of 40 cigarettes per day, at certain times and in automated equipment for cigarette burning, called smoking machine (SM-MC-01). After the exposure period, urine and blood samples were collected for the functional analyses, and the kidneys were dissected and submitted to histological procedures for morphoquantitative analyses. Results After exposure of animals of the Smoking Group, the following were observed: lower weight gain; lower water and feed intake; decreased renal weight, diameter, and volume; reduction in cortical thickness and glomerular volume density; decrease in glomerular and capsular diameter; increase in mesangial density; decreased urine volume; increased levels of glucose, serum creatinine and microalbuminuria; decreased urinary creatinine levels and creatinine clearance rate. Conclusion Passive smoking negatively influences renal morphology and glomerular filtration rate, with effects similar to those described in the literature regarding active smoking.