Renal hemodynamics in Otsuka Long-Evans Tokushima fatty rat, a model rat of spontaneous non-insulin-dependent diabetes mellitus with obesity

Global heterogeneity of glomerular volume distribution in early diabetic nephropathy

“…However, the difference in absolute volume between OLETF rats and LETO rats was eliminated after normalization to the kidney weights, resulting in failure to detect a change in glomerular volume in diabetic nephropathy. This finding was consistent with previous consequences based on histologic evaluations [18,21,22]. Specifically, an increase in estimated glomerular volume was accompanied with increase in total kidney mass under the hyperfiltrationstate in diabetes mellitus [23,24].…”

“…The general database of both strains of rats was as follows: (1) blood glucose value during surgery was significantly higher in OLETF rats (617 ± 161 mg/dL during surgery) than LETO rats (379 ± 66 mg/dL during surgery, P < 0.05), (2) the kidney weight was significantly larger in OLETF rats (2.5 ± 0.5 g) than LETO rats (1.5 ± 0.2 g, P < 0.05), and (3) the body weight was significantly larger in OLETF rats (639 ± 31 g) than LETO rats (497 ± 21 g, P < 0.0001), which were all consistent with those in similar age of OLETF rat and LETO rat in the previous report [18]. OLETF rats at 7 weeks had a body weight of 225 ± 18 g and a blood glucose concentration of 158 ± 37 mg/dL.…”

“…Uriu et al [18] demonstrated a significant increase in glomerular filtration rate in OLETF rats of 5 to 10 months old compared to the age-matched LETO rats. Thus, glomerular enlargement in OLETF rats in the present study corresponded to hyperfiltration-state.…”

Abnormal autoregulation and tubuloglomerular feedback in prediabetic and diabetic OLETF rats

“…Furthermore, there may be a stimulation of the sympathetic nervous system, but detailed examination in the OLETF rat has not been reported. A previous report by Uriu et al (26) indicates that hyperfiltration in OLETF rats precedes the development of diabetes and persists until about the 40-wk age range. Urine volume tends to decrease with aging in nondiabetic control [Long-Evans To-kushima Otsuka (LETO)] rats, whereas a marked diuresis and reduced osmotic urine concentration prevail in OLETF rats.…”

“…OLETF rats show insulin resistance at an early stage, lateonset hyperglycemia, and relatively mild obesity and hyperlipidemia, thus resembling the development of human type 2 diabetes (26). Comparable to the human disease, insulin resistance and overweight become apparent at 10 -12 wk of age preceding the appearance of frank hyperglycemia at ϳ20 wk of age that reaches blood glucose levels of Ͼ250 mg/dl at 30 wk.…”