Effects of cigarette smoke inhalation and coffee consumption on bone formation and osseous integration of hydroxyapatite implant / Os efeitos do cigarro e do consumo de café sobre a formação óssea e a integração óssea de implantes de hidroxiapatita

The present study aims to assess the effects of cigarette smoke inhalation and/or coffee consumption on bone formation and osseous integration of a dense hydroxyapatite (DHA) implant in rats. For this study, 20 male rats were divided into four groups (n = 5): CT (control) group, CE (coffee) group, CI (cigarette) group and CC (coffee + cigarette) group. During 16 weeks, animals in the CI group were exposed to cigarette smoke inhalation equivalent to 6 cigarettes per day; specimens in the CE group drank coffee as liquid diet; and rats in the CC group were submitted to both substances. In the 6th week a 5 mm slit in the parietal bone and a 4 mm slit in the tibia were performed on the left side: the former was left open while the latter received a DHA implant. As soon as surgeries were finished, the animals returned to their original protocols and after 10 weeks of exposure they were euthanised (ethically sacrificed) and the mentioned bones collected for histological processing. Data showed that exposure to cigarette smoke inhalation and coffee consumption did not interfere in weight gain and that solid and liquid diet consumption was satisfactory. Rats in the CC group showed a decrease in bone neoformation around the tibial DHA implant (31.8 ± 2.8) as well as in bone formation in the parietal slit (28.6 ± 2.2). On their own, cigarette smoke inhalation or coffee consumption also led to diminished bone neoformation around the implant and delayed the bone repair process in relation to the CT group. However, reduction in the bone repair process was accentuated with exposure to both cigarette smoke inhalation and coffee consumption in this study.

O presente estudo teve como objetivo avaliar os efeitos do tabagismo e do consumo de café, isolada ou concomitantemente, sobre a formação óssea e a osseointegração de implantes hidroxiapatita densa. Foram utilizados 20 ratos machos, divididos em quatro grupos (n = 5): grupo CT (controle); grupo CA (café); grupo CI (cigarro), e grupo CC (cigarro + café). Durante 16 semanas, os animais do grupo CI foram expostos à fumaça de seis cigarros/dia; os animais do grupo CA consumiram café como dieta líquida, e os animais do grupo CC, ambas as substâncias. Após seis semanas de exposição, uma falha óssea de 5 mm foi produzida no osso parietal esquerdo e de 4 mm, na tíbia esquerda dos animais. A falha do parietal foi mantida aberta, enquanto na tíbia corpos cerâmicos de hidroxiapatita densa (HAD) foram implantados em cavidade produzida cirurgicamente. Após as cirurgias, os animais retornaram aos protocolos experimentais e, ao término de dez semanas, foram eutanasiados, sendo as tíbias e os parietais coletados para processamento histológico. A exposição à fumaça do cigarro e o consumo de café não interferiram no ganho de peso dos animais, e os consumos de dieta líquida e sólida foram satisfatórios entre os grupos. Os animais do grupo CC apresentaram menor volume de osso neoformado ao redor do implante de HAD na tíbia (31,8 ± 2,8) e menor osteogênese na falha produzida no osso parietal (28,6 ± 2,2). O café e o cigarro consumidos isoladamente provocam a diminuição do volume de osso ao redor do implante e o atraso no processo de reparação óssea. Observou-se que o consumo de café associado à exposição à fumaça do cigarro reduziu de forma acentuada o processo de reparação óssea, no presente estudo.

Does heteropterys aphrodisiaca administration andendurance training alter bones of mature rats?

Heteropterys aphrodisiaca infusion, alone or associated with endurance training, was investigated in rat bonesin relation to their mechanical properties, collagen content and morphology. Male rats were divided into fourgroups (n = 8): CS- control sedentary, HS- H. aphrodisiaca sedentary, CT–control trained, HT‑H. aphrodisiacatrained. The training protocol consisted in running on a motorized treadmill, 5 times a week, for 8 weeks,with weekly increase in treadmill velocity and duration. Control groups received water while HS and HTgroups received H. aphrodisiaca infusion (104 mg/animal) by gavage during the 8 weeks. Tibiae werefrozen for collagen dosage and biomechanical analysis or preserved in Karnovsky’s fixative, then processedfor histomorphological analysis by conventional light microscopy and scanning electron microscopy. TheHT group showed significantly higher yield load and yield stress in the tibiae three-point bending test. Themaximum load, stiffness, maximum stress and elastic modulus were statistically similar for the experimentalgroups. The hydroxyproline content, morphometrical and stereological data were not significantly differentfor the four groups. Scanning electron microscopy showed more lacunae and Havers canals in the bone oftrained animals, moreover the osteons were more disorganized, when compared with sedentary groups. Thesealterations may indicate that the bone of trained animals was being remodeled. However, after 8 weeks oftraining, it was not possible verify alterations in morphometrical measurements, collagen content, stiffness andmodulus of elasticity of the trained and treated animals.