Assessment of the maximum uptake time of 99mTc-DMSA in renal scintigraphy in rat

Introduction: The optimal imaging time of a radionuclide scintigraphy is the time at which the organ of interest has the maximum uptake of the injected radionuclide. This study was performed to investigate the maximum uptake time of 99mTc-DMSA in rat renal scan. Methods: Renal scintigraphy was performed with 3 mCi of 99mTc-DMSA. Planar images were acquired every 20 minutes for 8 hours post-injection using a small-animal SPECT. Results: Activity and the count rate per pixel (CRPP) of the kidneys peaked 1 h post-injection, plateaued for about 1 h, and declined time-dependently. Kidney to background ratio (KBR) reached to 61.7% at 1 h after injection and remained almost constant afterwards. Conclusion: The kidneys had maximum emission and CRPP between 1 to 2 h after 99mTc-DMSA injection, whereas there was no significant difference between the KBRs after 1 h. Our results showed that image acquisition of 1-2 h post-injection is recommended for renal scintigraphy with DMSA in rat

Comparison of 99mTc-DMSA renal scintigraphy with biochemical and histopathological findings in animal models of acute kidney injury

Biochemical and histological assays are currently used for the diagnosis and characterization of kidney injury. The purpose of this study was to compare technetium- 99m-labeled dimercaptosuccinic acid (99mTc- DMSA) renal scintigraphy, as a non-invasive method, with common biochemical and histopathological methods in two animal models of acute kidney injury. Nephrotoxicity was induced either by gentamicin (100 mg/kg/day for one week) or unilateral ureteral ligation (UUO). Renal scintigraphy was performed 1 h after intravenous injection of 99mTc-DMSA (3 mCi). Furthermore, plasma levels of blood urea nitrogen (BUN), creatinine, sodium, and potassium were determined using an autoanalyzer. At the end of experiments, kidneys were excised for the measurement of activity uptake (mCi/gr) using a dose calibrator as well as histopathological examinations with hematoxylin and eosin (H&E) staining. There was a significant decrease in 99mTc-DMSA uptake in both gentamicin (P value = 0.049) and UUO (P value = 0.034) groups, and it was more significant in the former. The levels of BUN and creatinine increased in both gentamicin and UUO groups, while the levels of sodium and potassium remained unchanged. Furthermore, a strong correlation was found between DMSA uptake and histopathological findings. Scintigraphy with 99mTc-DMSA is capable of detection of kidney injury in both gentamicin and UUO groups. Moreover, a significant correlation was found between scintigraphy parameters and histopathological findings. This suggests 99mTc-DMSA as a non-invasive method for the evaluation of kidney injury induced by drugs or anatomical disorders

Serological, pathological and scintigraphic assessment of Hemiscorpius lepturus effects on renal dysfunction in rats

Objective(s): Hemiscorpius lepturus is one of the dangerous scorpions of Iran leading to acute kidney injury (AKI) especially in infants. The purpose of this animal study was to compare the serological, pathological and scintigraphic data to quickly predict the occurrence of this disorder.Materials and Methods: In two groups of animals, each contained five rats, H. lepturus venom (1200 µg/Kg) were injected intravenously via the tail vein. At three hours and one week later, 99m Tc-DMSA (3 mCi) was intravenously injected and renal scintigraphy was performed after an hour. Moreover, plasma levels of creatinine, sodium, potassium, and blood urea nitrogen (BUN) were measured. At the end of the study, renal tissues were excised and prepared to perform pathological evaluation after Hematoxylin and Eosin staining.Results: All serological indices were remained unchanged compared to control. A large number of glomerular fibrin thrombi with entrapped red blood cells and simplified tubular epithelium in dilated and ectatic tubules were observed in high power field (×100) four hours after envenomation, which reduced significantly one week later. In our scintigraphic study, there was a statistically significant difference (

Distant effects of unilateral renal ischemia/reperfusion on contralateral kidney but not lung in rats: the roles of ROS and iNOS

Acute kidney injury is usually associated with distant organ dysfunction. The roles of inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS) in this phenomenon were investigated following 2-h unilateral renal ischemia and 24-h reperfusion. There were three groups of rats subjected to either unilateral ischemia/reperfusion (UIR group), unilateral nephrectomy (UNX group), or sham-operation. Two further groups were given α-tocopherol and aminoguanidine with UIR (treated-UIR group) and UNX (treated-UNX group). Plasma nitrite/nitrate and malondialdehyde were elevated only in the UIR group. Creatinine clearance and blood flow increased in non-ischemic kidney of the UIR, but not to the same extent as remnant kidney of the UNX group, while they had equal compensatory rises in absolute NaThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

A Comparative Analysis of Saffron and Methylprednisolone on Bleomycin-Induced Pulmonary Fibrosis in Rats

Background: The purpose of this study was to compare the effects of saffron and methylprednisolone on bleomycin-induced pulmonary fibrosis in rats. Methods: This study was conducted in Bushehr, southern Iran in 2017.The animals were divided into four groups of five rats each. Three groups were injected with a single intratracheal dose of bleomycin (5 mg/kg). The fourth group was administered with normal saline at the same volume (200 µl). Saffron extract dissolved in water was given to one group (100 mg /body weight) orally while intraperitoneal injection of methylprednisolone (2.5 mg/kg) injected to another one for 16 days. The rats were sacrificed 28 days following surgery and their right and left lungs were removed and washed for measuring lung indices, myeloperoxidase activities and finally histopathological examination. Results: Injection of bleomycin caused decrement of body weight aggravated by intraperitoneal methylprednisolone treatment. Lung indices were increased in the bleomycin-treated group compared with the control, while methylprednisolone, unlike saffron, had no preventive effects on it. Both saffron and methylprednisolone treatment prevented the increase in lung myeloperoxidase as a destructive enzyme. In addition, excessive collagen deposition and thickening of alveolar septa were significantly prevented with saffron treatment as compared to methylprednisolone injection following hematoxylin and eosin staining. Conclusion: Saffron with established antioxidant properties could prevent some detrimental effects in bleomycin-induced pulmonary fibrosis even more than methylprednisolone injection known as a standard therapy in this murine model. More investigations must be carried out to examine the beneficial or harmful effects of this remedy

Hemodynamic Changes in Experimentally Envenomed Anaesthetized Rats by Intravenous Injection of Hemiscorpius lepturus Venom

Background: We investigated the hemodynamic changes (Inotropic, chronotropic and arrhythmogenic) in intrave­nously envenomed anesthetized rats with Hemiscorpius lepturus venom. The neutralizing potencies of different drugs and commercial antivenom were assessed simultaneously. Methods: Different doses of the crude venom (100, 200 and 400μg/rat) were injected during five minutes via the femoral vein and cardiovascular changes were recorded in rats in Razi Institute Corporation, Karaj, Iran in 2017. The drugs (Atropine, lidocaine, propranolol and prazosin) were injected before the venom for determination of the coun­teracting effects. Different volumes (100, 500 and 1000µl) of the antivenom were pre envenomed to neutralize cardi­ovascular changes. Results: Temporary hypertension and bradycardia with no arrhythmogenic effects were depicted within twenty minutes. There was a difference in arterial pressure between the venom (400μg/rat) and the vehicle at 8 minutes (114.68±5.1mmHg versus 70.2±4.3mmHg). Elevation of the mean arterial pressure was inhibited by propranolol (2 mg/kg) and neutralized by prazosin (1mg/kg) while lidocaine (4mg/kg) and atropine (1mg/kg) had no effects. Pre­medication with Iranian commercial antivenom (1000μl) produced surprisingly temporary hypertension compared to the vehicle (140.84±4.5 versus 84.3±3.2). It had no neutralizing properties on blood pressure variation before the venom injection. Volume-expanded hypertension phenomenon was ruled out in a parallel study. Conclusion: This venom has vasoconstrictive effects in rats probably due to the presence of norepinephrine like ma­terials in its content or liberated from adrenal gland inhibited by prazosin premedication. The neutralizing effects of antivenom on venom-induced hypertension are questionable

Saffron Protection against Bleomycin-Induced Pulmonary Fibrosis in Rats

Background: Bleomycin-induced lung fibrosis has been accepted as an animal model for fibrosis in rats. The aim of this study was to evaluate the effects of saffron aqueous extract on this disorder paving the way for more investigation in treating idiopathic pulmonary fibrosis in human. Methods: Male Wistar rats (250–300 gr) were instilled a single dose of bleomycin (5 mg/kg) via intratracheal tube (n=6) in 2015. Sham group received normal saline. Saffron aqueous extract (50 mg/kg and 100 mg/kg) were given orally in two different treated groups with bleomycin for 28 days. Lung Indices was calculated at the end of this experiment. Lung segments fixed in 10% formaldehyde were used for pathological preparation with Hematoxylin & Eosin and trichrome staining. Results: The body weight was decreased and lung Indices increased in bleomycin group (P<0.5). Bleomycin administration increased myeloperoxidase, malondialdehyde and finally TNF-α in lung tissue homogenates (P<0.05) compared with sham group. The fibrotic process and thickening of alveolar septa in treated rats with bleomycin were increased by H&E and Masson Trichrome staining. Saffron treatment (50 and 100 mg/kg) attenuated the increase in MDA (264.43±10.4 nmol/g by the higher dose versus 378.4±18.1nmol/g), MPO (0.19±0.03 and 0.13± 0.04 IU/ml versus 0.39.2±0.05 IU/ml) and TNF-α level (18.42±3.7 ng/ml and14.31±3.6 ng /ml versus 35.32±4.2) in lung homogenates compared to bleomycin group (P<0.05). It decreased collagen accumulation and alveolar destructive patterns in pulmonary fibrosis. Conclusion: This study introduces saffron as novel anti-fibrotic agent against bleomycin-induced fibrosis due to histological examinations and preventive effects on destructive enzyme release in rats