RESUMO
In pigs, a paternally (pat) imprinted mutation in the IGF-II gene is associated with increased muscle mass and decreased backfat thickness. The aim of this study was to determine whether this mutation influenced cellular, biochemical and metabolic features of skeletal muscle and adipose tissue. Muscle (trapezius) and subcutaneous adipose tissue (SCAT) were collected from pigs (106kg) carrying (Qpat, n=6) or not carrying (qpat, n=7) the mutation. Adipocytes were isolated from those tissues by collagenase treatment. Lipid content and activity of lipogenic enzymes were determined using standard assays. Gene expression levels were determined by real-time PCR. Levels of IGF-II mRNA were higher (P<0.01) in muscle of Qpat than in that of qpat pigs, but they did not differ significantly between the two groups in SCAT. Whereas levels of IGF-I mRNA in muscle were similar in both groups, they were higher (P<0.05) in SCAT of Qpat pigs than in that of qpat pigs. Muscle lipid content and intramuscular adipocyte diameters were not influenced significantly by the IGF-II genotype. In SCAT, the reduction of backfat thickness in Qpat pigs compared with qpat pigs was associated with lower (P<0.05) lipid content and smaller (P<0.05) adipocytes, with no significant genotype-effects on expressions and/or activities of lipogenic enzymes. In summary, our results suggest that the IGF-II mutation altered body composition in pigs by favoring myofiber hypertrophy and repressing adipose cell development in SCAT.
Assuntos
Fator de Crescimento Insulin-Like II/genética , Fator de Crescimento Insulin-Like II/metabolismo , Metabolismo dos Lipídeos/genética , Músculo Esquelético/metabolismo , Gordura Subcutânea/metabolismo , Suínos/genética , Suínos/metabolismo , Adipócitos/citologia , Adipócitos/metabolismo , Animais , Contagem de Células/veterinária , Tamanho Celular , Ácido Graxo Sintase Tipo I/genética , Ácido Graxo Sintase Tipo I/metabolismo , Feminino , Expressão Gênica , Histocitoquímica/veterinária , Fator de Crescimento Insulin-Like I/biossíntese , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like II/biossíntese , Malato Desidrogenase/genética , Malato Desidrogenase/metabolismo , Masculino , Músculo Esquelético/citologia , Músculo Esquelético/enzimologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptor IGF Tipo 1/biossíntese , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Receptor IGF Tipo 2/biossíntese , Receptor IGF Tipo 2/genética , Receptor IGF Tipo 2/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Gordura Subcutânea/citologia , Gordura Subcutânea/enzimologiaRESUMO
BACKGROUND: Determining the cellular content of saliva by means of conventional microscopy chamber counting is a very time-consuming and operator-sensitive procedure. This study concentrated on the use of flow cytometry to examine the cellular content of saliva. Erythrocytes, leukocytes, epithelial cells and bacteria were quantified and the results were compared with caries experience and the presence of gingivitis. METHODS: 258 uncentrifuged vortexed paraffin-stimulated saliva samples (112 males and 146 females) were analyzed with the UF-100 flow cytometer. Salivary reference values were established for erythrocyte, leukocyte, epithelial cell and bacterial count. Caries experience (DMF) and the presence of gingivitis were recorded. RESULTS: Caries experience or caries risk could not be assessed with flow cytometry. However, salivary flow cytometry may be useful in determining an individual's risk for gingivitis: a significant increase in salivary leukocytes was observed in individuals with gingivitis. At a cut-off level of 10(3) leukocytes micro l(-1) saliva, a sensitivity of 76% and a specificity of 45% was obtained. Other analytes were not significantly different between individuals with and without gingivitis. CONCLUSION: Flow cytometry of paraffin-stimulated human saliva seems a promising diagnostic or predictive tool and further investigations of diseases of the oro-pharyngeal loge, such as tonsillitis and periodontitis, should be carried out in the future.
