Rat pancreatectomy combined with isoprenaline or uninephrectomy as models of diabetic cardiomyopathy or nephropathy

Abstract: Cardiovascular and renal complications are the predominant causes of morbidity and mortality amongst patients with diabetes. Development of novel treatments have been hampered by the lack of available animal models recapitulating the human disease. We hypothesized that experimental diabetes in rats combined with a cardiac or renal stressor, would mimic diabetic cardiomyopathy and nephropathy, respectively. Diabetes was surgically induced in male Sprague Dawley rats by 90% pancreatectomy (Px). Isoprenaline (Iso, 1 mg/kg, sc., 10 days) was administered 5 weeks after Px with the aim of inducing cardiomyopathy, and cardiac function and remodeling was assessed by echocardiography 10 weeks after surgery. Left ventricular (LV) fibrosis was quantified by Picro Sirius Red and gene expression analysis. Nephropathy was induced by Px combined with uninephrectomy (Px-UNx). Kidney function was assessed by measurement of glomerular filtration rate (GFR) and urine albumin excretion, and kidney injury was evaluated by histopathology and gene expression analysis. Px resulted in stable hyperglycemia, hypoinsulinemia, decreased C-peptide, and increased glycated hemoglobin (HbA1c) compared with sham-operated controls. Moreover, Px increased heart and LV weights and dimensions and caused a shift from α-myosin heavy chain (MHC) to β-MHC gene expression. Isoprenaline treatment, but not Px, decreased ejection fraction and induced LV fibrosis. There was no apparent interaction between Px and Iso treatment. The superimposition of Px and UNx increased GFR, indicating hyperfiltration. Compared with sham-operated controls, Px-UNx induced albuminuria and increased urine markers of kidney injury, including neutrophil gelatinase-associated lipocalin (NGAL) and podocalyxin, concomitant with upregulated renal gene expression of NGAL and kidney injury molecule 1 (KIM-1). Whereas Px and isoprenaline separately produced clinical endpoints related to diabetic cardiomyopathy, the combination of the two did not accentuate disease development. Conversely, Px in combination with UNx resulted in several clinical hallmarks of diabetic nephropathy indicative of early disease development

Effects of sertindole on sleep-wake states, electroencephalogram, behavioral patterns, and epileptic activity of rats

Contains fulltext : 29052.pdf (publisher's version ) (Open Access)In this study we addressed the effects of the 5-HT2 receptor antagonist sertindole in rats. The compound was administered in doses of 0.08, 0.32, and 1.28 mg/kg, whereas a control group received the solvent. The effects of sertindole on sleep-wake states, behavioral patterns, and background electroencephalogram were studied. Following injection of drug or solvent, we recorded the electroencephalogram and electromyogram for two periods of 4 h in the dark period of the light-dark cycle on 2 successive days. On the 1st day sertindole induced a significant increase in deep slow-wave sleep, but only with a dose of 0.32 mg/kg. Furthermore, a decrease in REM sleep in all three drug groups was established. The suppression of REM sleep was still present on the 2nd day. Sertindole also induced a decrease in alternation between behavioral patterns on the 1st day. There were no significant changes in the spectral content of the background electroencephalogram. In a parallel experiment it appeared that sertindole had no main effects on epileptic spike-wave discharges. This was established with a dose of 1.28 mg/kg sertindole in rats with absence seizures. These findings suggest that sertindole, similar to other compounds modulating 5-HT2 receptors, influences sleep-wake states in rats by decreasing REM sleep and mildly increasing deep slow-wave sleep, whereas behavioral variation is slightly diminished, with no effects on the background EEG and almost no effects on spike-wave discharges