effect of endurance training in changes of blood lactate and plasma calcitonin gene related peptide levels in type 2 diabetic rats

Streptozotocin-induced type2 diabetes causes functional and metabolic changes in some tissues and subsequently produces some intermediates and substances which enter the circulation. On the other hand, endurance training can modify the amount of these substances. In this study, the effects of diabetes and endurance training on resting levels of blood lactate and plasma calcitonin gene- related peptide [CGRP] were investigated. Fifty rats were divided into 4 groups including control nondiabetic [n=10] training nondiabetic [n=10] nontraining diabetic [n=15] and training diabetic. Diabetes was induced by feeding with high fat diet HFD and injecting STZ. The training groups underwent an endurance training program on treadmill. Blood Lactate concentration was measured by a lactate kit and plasma CGRP concentration was determined by enzyme immunoassay kit [EIA]. In the control nondiabetic, training nondiabetic, nontraining diabetic control and training diabetic groups, the restig values of blood lactate were 2.4, 2.08, 4.5, 3.7 [mmol/L] and plasma CGRP values were 0.40, 0.35, 4.9,3.0 [ng/ml], respectively. Resting levels of circulating lactate and CGRP were higher in diabetic subjects than in control nondiabetic rats and endurance training decreased resting value of blood lactate in diabetic rats but did not change the plasma CGRP. Thus, it seems that the role of endurance training in ameliorating diabetes is due to decreasing resting level of blood lactate, but not plasma CGRP

Gen de la calcitonina: síntesis química y expresión en Escherichia coli / Human calcitonine gene: chemical synthesis and expression in Escherichia coli

La calcitonina es una hormona polipéptida de 32 aminoácidos que interviene en la regulación del metabolismo del fósforo y el calcio en los vertebrados. En este trabajo presentamos los resultados de la síntesis química y la expresión directa de los genes humanos de calcitonina en E. coli. Para evitar la acción recombinante de la calcitonina contra proteasas bacteriales, se construyó una serie de genes oligómeros de calcitonina que codifican proteínas multidominio con un número variable de monómeros. Se expresaron bajo el control de un promotor fuerte sintético y en un sitio de unión al ribosoma, y se encontró que en el gen de calcitonina tetrámera daba un producto estable del 13 % de rendimiento del total de la proteína bacteriana. La calcitonina recombinante multidominio puede pasar a forma monómera mediante tratamiento con BrCN