Extracellular HSP70 levels in diabetic environment in rats

Abstract

The expression of HSP70 in embryonic cells of mammals and its role for their normal development and protection is an important aspect to be investigated in pregnancy and/or mild diabetes. In this sense, the present study evaluated the effects of mild diabetes on maternal reproductive parameters and HSP70 levels in Wistar rats at different stages of life and in their offspring. Mild diabetes was induced by a betacytotoxic drug (streptozotocin) at birth. Four experimental groups were evaluated: at 90 days of age: nonpregnant nondiabetic (ND90) and nonpregnant mild diabetic (D90) female rats, and at term pregnancy: pregnant female rats of both glycemic status were examined (NDP and DP, respectively). The rats were submitted to oral glucose tolerance test, and blood samples were collected for determination of HSP70 levels. In addition, the reproductive performance of pregnant rats was assessed and HSP70 levels determined in their offspring blood samples. The HSP70 levels and maternal reproductive performance presented no difference between ND and D rats, regardless of the life stage. The HSP70 levels were increased in D90 rats and lower in offspring from D rats. Maternal HSP70 levels were positively correlated to the number of dead embryos. In conclusion, mild diabetes did not affect maternal reproductive performance, but high maternal HSP70 levels compromised embryo development. In addition, offspring from D rats exhibited lower HSP70 levels, showing that this protein can be used as an indicator of metabolic consequences of diabetes and predictor of related disorders in adulthood.

Mild diabetes: long‐term effects on gastric motility evaluated in rats

“…Recently, mild diabetes model was characterized by changes in two or more points in the glucose curve during OGTT (Santos et al . ). Measurements of OGTT three months after induction indicate that diabetic rats have a late response to endogenous insulin during glucose uptake in at least two points (Figure ), confirming the success of our model.…”

“…; Santos et al . ). Mild diabetic state was confirmed when two or more time points on the glycaemic curve were higher than 140 mg/dl (Santos et al .…”

“…Glucose solution (200 g/l) was administered to the animals by gavage after 8-h fasting. Blood samples were collected from a cut tip tail at time 0 (before glucose overload), 30, 60 and 120 minutes (min) before administration, to determine the glucose level using a glucometer Easy True Read â (Home Diagnostics, Fort Lauderdale, FL, USA) (Santos et al 2015).…”

“…Adult animals present with an abnormal oral glucose tolerance test, consistent with mild diabetes (Santos et al . ). This diabetic status reproduces the blood glucose level similar to type 2 or gestational DM.…”

“…Streptozotocin (STZ) is a diabetes induction drug which is administered during the neonatal period in rats to produce diabetes with mild glycaemic intensity in adult life (Sinzato et al 2012). Adult animals present with an abnormal oral glucose tolerance test, consistent with mild diabetes (Santos et al 2015). This diabetic status reproduces the blood glucose level similar to type 2 or gestational DM.…”