A novel model of surgical injury in adult rat kidney: a "pouch model"

Altered Emotional Phenotypes in Chronic Kidney Disease Following 5/6 Nephrectomy

Increased prevalence of chronic kidney disease (CKD) and neurological disorders including cerebrovascular disease, cognitive impairment, peripheral neuropathy, and dysfunction of central nervous system have been reported during the natural history of CKD. Psychological distress and depression are serious concerns in patients with CKD. However, the relevance of CKD due to decline in renal function and the pathophysiology of emotional deterioration is not clear. Male Sprague Dawley rats were divided into three groups: sham control, 5/6 nephrectomy at 4 weeks, and 5/6 nephrectomy at 10 weeks. Behavior tests, local field potentials, and histology and laboratory tests were conducted and investigated. We provided direct evidence showing that CKD rat models exhibited anxiogenic behaviors and depression-like phenotypes, along with altered hippocampal neural oscillations at 1–12 Hz. We generated CKD rat models by performing 5/6 nephrectomy, and identified higher level of serum creatinine and blood urea nitrogen (BUN) in CKD rats than in wild-type, depending on time. In addition, the level of α-smooth muscle actin (α-SMA) and collagen I for renal tissue was markedly elevated, with worsening fibrosis due to renal failures. The level of anxiety and depression-like behaviors increased in the 10-week CKD rat models compared with the 4-week rat models. In the recording of local field potentials, the power of delta (1–4 Hz), theta (4–7 Hz), and alpha rhythm (7–12 Hz) was significantly increased in the hippocampus of CKD rats compared with wild-type rats. Together, our findings indicated that anxiogenic behaviors and depression can be induced by CKD, and these abnormal symptoms can be worsened as the onset of CKD was prolonged. In conclusion, our results show that the hippocampus is vulnerable to uremia.

The effect of zinc on healing of renal damage in rats

Background:

Several studies have previously been performed to promote kidney healing after injuries. Objectives: The aim of this study was to investigate the effect of zinc on renal healing after traumatic injury in rats.

Materials and Methods:

Forty healthy female rats were selected and one of their kidneys was incised. Half of the incisions were limited only to the cortex (renal injury type I) and the other ones reached the pelvocalyceal system of the kidney (renal injury type II). All the rats in the zinc treated group (case group) received 36.3 mg zinc sulfate (contained 8.25 mg zinc) orally. After 28 days, the damaged kidneys were removed for histopathological studies.

Results:

In the rats with type I injury, kidney inflammation of the case group was significantly lower than that of the control group. However, the result was not significant in rats with type II injury. Tissue loss and granulation tissue formation were significantly lower in the case group than the control group in both type I and II kidney injuries.

Conclusions:

Overall, Zinc can contribute to better healing of the rat’s kidneys after a traumatic injury.

Evaluation of Renal-Hepatic Functional Indices and Blood Pressure Based on the Progress of Time in a Rat Model of Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is defined as either kidney damage or a decline in renal function as determined by a decreased glomerular filtration rate (GFR) for three months or longer. CKD is an important risk factor for mortality.

OBJECTIVES

The aim of this study was to evaluate the effects of CKD on renal-hepatic functional indices and blood pressure in 5/6 nephrectomized (5/6 Nx) rats over the course of nine months.

MATERIALS AND METHODS

Male Wistar rats were subjected to either 5/6 Nx or sham operations (n = 8). Members of the sham group underwent the same procedure without surgical reduction of the kidney mass. For all animals, body weight (BW), serum creatinine (Cr), blood urea nitrogen (BUN), alanine transaminase (ALT), and aspartate transaminase (AST) levels were measured before and after surgery. After two-, three-, six-, and nine-month intervals, blood was collected to assay renal and hepatic functional indices. Tail-cuff blood pressure was recorded in each month after surgery.

RESULTS

BW was lower for the 5/6 Nx group rats after the operations compared with the BW of those in the sham operation group. Furthermore, the 5/6 Nx group showed elevations in blood pressure, Cr, BUN, ALT, and AST levels compared with the sham group over the course of time.

CONCLUSIONS

In summary, CKD induced by the 5/6 Nx model caused hypertension and increased serum levels of Cr, BUN, ALT, and AST. These changes are augmented by the progress of time.