Morphometry and histomorphometry of the testis in crossbred pigs fed diets with different protein levels / Morfometria e histomorfometria do testículo em suínos híbridos recebendo dietas com diferentes níveis de proteína

Aiming to evaluate the effect of the diet protein content on testicular parameters in pigs, 21 non-gelded male Dalland pigs were used and randomly divided into three groups. Males belonging to groups G2 and G3 received a diet with crude protein levels of 15% below and above, respectively, in relation to G1 (control). At 210 days of age, animals were castrated, and testis and epididymis were collected for morphometric and histomorphometry analyses. No difference was observed in relation to the total length of seminiferous tubules (G1=3239.9±333,3m; G2=2989.4±171,7m and G3=3059.5±254.9m), population of Sertoli cell (G1=4.7±0.5x10(9); G2=4.3±0.3x10(9) and G3=4.7±0.5x10(9)), population (G1=31.6±5.58x10(9); G2=27.3±4.0x10(9) and G3=26.4±3.9x10(9)) and volume of Leydig cells (G1=1289.3±182.6µm³; G2=1179.1±85.4µm³ and G3=1133.3±37.8µm³) and sperm production (G1=5.9±0.9x10(9); G2=5.6±0.6x10(9) and G3=5.1±0.3x10(9)). Protein levels were sufficient to maintain spermatogenesis in different experimental groups. It can be concluded that the magnitude of variation in levels of protein used in different stages of development was not sufficient to promote significant changes in testicular development and spermatogenesis process in adult animals.(AU)

Avaliou-se o efeito do teor de proteína da dieta sobre características testiculares em suínos, utilizando-se 21 suínos da raça Dalland, distribuídos aleatoriamente em três grupos. Os animais do G2 e G3 receberam dieta com porcentagens de proteína bruta de 15% para mais e para menos, respectivamente, em relação ao G1 (controle). Aos 210 dias de idade, os animais foram orquiectomizados e os testículos e epidídimos foram coletados para análises morfométricas e histomorfométricas. Observou-se efeito significativo da porcentagem de proteína sobre o comprimento e a largura dos testículos, e nenhuma diferença foi identificada em relação ao comprimento total dos túbulos seminíferos (G1=3239,9±333,3m; G2=2989,4±171,7m e G3=3059,5±254,9m), à população de células de Sertoli (G1=4,7±0,5x10(9); G2=4,3±0,3 x10(9) e G3=4,7±0,5x10(9)), à população (G1=31,6±5,58x10(9); G2=27,3±4,0x10(9) e G3=26,4±3,9x10(9)) e ao volume das células de Leydig (G1=1289,3±182,6µm³; G2=1179,1±85,4µm³ e G3=1133,3±37,8µm³) e à produção espermática (G1=5,9±0,9 x10(9); G2=5,6±0,6x10(9) e G3=5,1±0,3x10(9)). Os percentuais de proteína foram suficientes para a manutenção da espermatogênese nos diferentes grupos. Pode-se concluir que a magnitude da variação dos níveis de proteína usada em diferentes fases do desenvolvimento não foi suficiente para promover alterações significativas no desenvolvimento testicular e no processo espermatogênico em animais adultos.(AU)

Expressão da caderina na discondroplasia tibial / Cadherin expression in the tibial dyschondroplasia

By immunohistochemistry the expression of a pan-cadherin antibody that recognizes a wide variety of cadherins in chondrocytes from normal and tibial dyschondroplasia (TD) growth plates was compared. Surprisingly, an upregulated expression that was not expected in TD lesion chondrocytes was observed. The reason for this apparent upregulation is not clear. The increased expression may simply be due to the particular phenotype of lesion chondrocytes, and cadherin may be involved in apoptosis of chondrocytes of TD lesion. Another possibility, is that a low level of calcium in the lesion may be responsible for the observed upregulation. The results of the present study suggest that the formation of the dyschondroplastic lesion is not merely due to the impaired terminal differentiation of lesion chondrocytes and that other mechanisms are probably involved in TD etiology. Further studies will be necessary to provide insight into the precise nature of the condition.(AU)

Expressão imunoistoquímica da proteína S-100 na discondroplasia da tíbia / S-100 protein immunostaining in tibial dyschondroplasia

It was compared, by immunohistochemistry, the expression of S-100 protein from normal and tibial dyschondroplasia (TD) growth plates. The results suggest that S-100 may be involved in growth plate homeostasis. The expression of S-100 in dyschondroplastic chondrocytes may be due to a low level of calcium in the lesion and/or compression of chondrocytes by the accumulated matrix. One further possibility is the association between S-100 and the regulation of matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs). Further studies will be necessary to provide insight into involvement of S-100 in tibial dyschondroplasia development and the precise nature of the pathology.(AU)