RESUMO
People with type 1 diabetes (T1D) require exogenous administration of insulin, which stimulates the translocation of the GLUT4 glucose transporter to cell membranes. However, most bloodstream cells contain GLUT1 and are not directly affected by insulin. Here, we report that C-peptide, the 31-amino acid peptide secreted in equal amounts with insulin in vivo, is part of a 3-component complex that affects red blood cell (RBC) membranes. Multiple techniques were used to demonstrate saturable and specific C-peptide binding to RBCs when delivered as part of a complex with albumin. Importantly, when the complex also included Zn2+, a significant increase in cell membrane GLUT1 was measured, thus providing a cellular effect similar to insulin, but on a transporter on which insulin has no effect.
Assuntos
Peptídeo C/administração & dosagem , Eritrócitos/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Soroalbumina Bovina/química , Zinco/administração & dosagem , Trifosfato de Adenosina/química , Animais , Transporte Biológico , Bovinos , Membrana Celular/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Regulação da Expressão Gênica , Glucose/metabolismo , Humanos , Insulina/metabolismoRESUMO
Type 1 diabetes is associated with such complications as blindness, kidney failure, and nerve damage. Replacing C-peptide, a hormone normally co-secreted with insulin, has been shown to reduce diabetes-related complications. Interestingly, after nearly 30 years of positive research results, C-peptide is still not being co-administered with insulin to diabetic patients. The following review discusses the potential of C-peptide as an auxilliary replacement therapy and why it's not currently being used as a therapeutic.
Assuntos
Peptídeo C/uso terapêutico , Complicações do Diabetes/terapia , Diabetes Mellitus Tipo 1/terapia , Insulina/uso terapêutico , Animais , Bibliometria , Peptídeo C/deficiência , Peptídeo C/história , Peptídeo C/farmacocinética , Ensaios Clínicos como Assunto , Complicações do Diabetes/história , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Diabetes Mellitus Tipo 1/história , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Modelos Animais de Doenças , História do Século XX , História do Século XXI , Humanos , Insulina/deficiência , Insulina/história , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Ferro/metabolismo , Ligação Proteica , Albumina Sérica/metabolismo , Albumina Sérica/farmacocinética , Zinco/metabolismoRESUMO
Feeding related lateralization was examined in a population of 23 small-eared bushbabies (Otolemur garnettii). The three measures used to determine lateralization were food reaching, holding, and manipulation. Sex and age differences were found, with adult females showing a strong right bias and adult males a left bias. Juvenile males were weakly lateralized and less consistent across measures than adult animals. The use of standard scores to assess lateralization allowed species comparisons to be made. The results of this study were compared with results from a previous study on lateralization in the ring-tailed lemur (Lemur catta). Species comparisons found sex differences to be a stronger factor in lateralization than species differences.