Determination of Ghrelin Immunoreactivity in Kidney Tissues of Diabetic Rats

Abstract

Backgrounds/Aims. Ghrelin, a recently discovered hormone, is released largely from stomach and might affect insulin secretion and glucose metabolism. The aim of this study was to determine the immunohistochemical localization of ghrelin in streptozotocin-induced diabetic rat kidneys. Methods. Fifty-four adult male Wistar rats were used in this study. All rats were divided into nine groups according to three time points of the study (2, 4, and 6 weeks) as control group, control group given 0.1 M phosphatecitrate, and diabetic group given 50 mg/kg streptozotocin intraperitoneally. The rats in all groups were decapitated at the end of 2, 4, and 6 weeks of the study. The kidneys of the rats were removed, and tissue samples were processed by using routine paraffin techniques. The samples were immunohistochemically stained using avidin-biotin-peroxidase method for ghrelin immunoreactivity. Results. There were no differences of ghrelin immunoreactivity between the control groups. Ghrelin immunoreactivity was observed in both distal tubulus and collecting ducts in the diabetic groups, while it was detected only in distal tubules of the control groups. The intensity of ghrelin immunoreactivity was increased at 4 and 6 weeks of the study in the diabetic groups. Conclusion. Increased ghrelin immunoreactivity in the diabetic rat kidney tissues suggests that ghrelin may contribute to the pathophysiological mechanism of diabetic nephropathy.

Expression of Ghrelin and GHSR-1a in Long Term Diabetic Rat's Kidney

“…In a study investigating the effect of enalapril and losartan on ghrelin immunoreactivity, it was shown that the immunoreactivity was significantly increased in the kidneys of diabetic rats (Donder et al 2013). Other studies showed that ghrelin immunoreactivity in the distal and collecting tubules was gradually increased with duration of diabetes (Yabuki et al 2006;Kuloglu and Dabak 2009). In the present study, ghrelin immunoreactivity was observed in the distal and collecting tubules in the control group, whereas it was also observed in the proximal tubules in the diabetes groups.…”

“…Total and active ghrelin levels were significantly increased in STZ-induced diabetic rats (Masaoka et al 2003). It has been suggested that increased ghrelin levels in diabetes contributed to the pathogenesis of nephropathy by increasing GH levels (Kuloglu and Dabak 2009). However, there are unsatisfactory data on ghrelin and ghrelin receptor (GHSR-1a) mRNA expression levels in the diabetic kidney.…”