RESUMO
INTRODUCTION: Amino acid transport across the placenta is crucial for fetal growth. In rodent models, the visceral yolk sac (referred to as yolk sac hereafter) is also likely to contribute to fetal amino acid provision. System L amino acid transporters mediate the transport of essential amino acids. System L activity is mediated by light chains LAT1 (Slc7a5) and LAT2 (Slc7a8) which form functional complexes by heterodimeric linkage to CD98 (Slc3a2). LAT4 (Slc43a2) is monomeric, possessing overlapping amino acid substrate specificity with LAT1 and LAT2. METHODS: This study investigates the expression of these LAT subtypes in fetus-matched rat placenta and yolk sac. RESULTS: Slc7a5, Slc7a8 and Slc43a2 transcripts were expressed in placenta and yolk sac with similar expression patterns between sexes. LAT1 expression was significantly higher in placenta than yolk sac. Conversely, LAT2 and LAT4 expression was significantly higher in yolk sac than placenta; CD98 expression was comparable. LAT1, LAT2, LAT4 and CD98 were distributed to rat placental labyrinth zone (LZ) and junctional zone (JZ). LAT1 and LAT4 demonstrated higher expression in LZ, whilst LAT2 was more intensely distributed to JZ. LAT1, LAT2, LAT4 and CD98 were expressed in yolk sac, with punctate LAT1 staining to endodermal cell cytoplasm, contrasting with the intense LAT2, LAT4 and CD98 endodermal cell basolateral distribution, accounting for greater LAT2 and LAT4 expression in yolk sac compared to placenta. CONCLUSION: LAT1, LAT2 and LAT4 are expressed in rat placenta and yolk sac implicating a combined role for these LAT subtypes in supporting fetal growth and development.
Assuntos
Sistema L de Transporte de Aminoácidos/genética , Placenta/metabolismo , Saco Vitelino/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sistema L de Transporte de Aminoácidos/classificação , Sistema L de Transporte de Aminoácidos/metabolismo , Sistema y+ de Transporte de Aminoácidos/genética , Sistema y+ de Transporte de Aminoácidos/metabolismo , Animais , Feminino , Cadeias Leves da Proteína-1 Reguladora de Fusão/genética , Cadeias Leves da Proteína-1 Reguladora de Fusão/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Transportador 1 de Aminoácidos Neutros Grandes/genética , Transportador 1 de Aminoácidos Neutros Grandes/metabolismo , Masculino , Gravidez , Ratos , Ratos WistarRESUMO
PURPOSE: To understand the geometry of the proximal humerus and glenoid fossa to facilitate the design of components used in shoulder arthroplasty. The aim is to evaluate the geometry of the proximal humerus and glenoid fossa and their relationship using a MicroScribe 3D digitizer. METHODS: Scans and measurements were obtained from 20 pairs of dry proximal humeri and scapulae [10 female and 10 male cadavers: median age 81 years (range 70-94 years)] using a MicroScribe 3D digitizer and Rhinoceros software. RESULTS: Means (±SD) of humeral inclination, medial wall angle of the bicipital groove, and radius of the humeral head values were 135 ± 11°, 39 ± 19°, and 14 ± 3 mm, respectively. Means (±SD) of glenoid height and width were 35 ± 4 and 26 ± 4 mm, while the means (±SD) of the angles of glenoid inclination, retroversion, and rotation were 87 ± 32°, 96 ± 10°, and 9 ± 6°, respectively. A significant difference in glenoid height (P ≤ 0.002) and width (P ≤ 0.0001) was observed between males and females, despite them having almost an identical radius of the humeral head, glenoid inclination, retroversion, and angle of rotation. There was also a significant difference (P ≤ 0.01) in the angle of glenoid retroversion between the right and left sides. CONCLUSIONS: Using a MicroScribe 3D digitizer, the glenoid fossa was observed to be significantly smaller in females than males; furthermore, there was a difference in glenoid retroversion between the right and left sides.
