Effect of renal denervatoin on the glomerular filtration rate [GFR] and tubular function

The renal nerves are the communicating link between the central nervous system [CNS] and the kidney, contributing importantly to homeostatic regulation, renal blood flow [RBF], glomerular filtration rate [GFR], renal tubular solute and water transport and hormonal release. In patho-physiological conditions, abnormal regulation of efferent nerve activity constitutes significantly to associated abnormalities of renal function which in turn are of importance in the pathogenesis of many diseases such as hypertension. Denervation is a method commonly used to study the role of renal nerves in the control of kidney function, also it is mandatory in cases of kidney transplantation and when using ganglion blockers. To study the effect of renal denervation on kidney function in dog, using unilateral renal Denervation and split urine collection model. The left kidney was denervated through an abdominal approach. Urine and blood samples were collected for six clearance periods [10 minutes each]. The following parameters were done: Urine flow rate Uv [ml/min/m[2] surface area]. GFR [ml/min/m[2]] by inulin clearance method [C[1n]] Urinary excretion rate for Na[+], K[+], Cl[-l] [U[Na+] V, U[K+] V, U[cl-]. V for denervated [DNX] and innervated [INN] kidneys. Percentage fractional excretion of Na[+] [%FE[Na+] was also calculated for both kidneys. Marked diuresis, natriuresis, kaliuresis, chloresis and increased% FE Na[+] and GFR for the denervated [DNX] kidney were found as compared to the innervated [INN] control. Renal denervation results in marked diuresis and solute loss in the acute stage, therefore it is recommended to compensate for these losses especially in the early stages of renal Denervation whether surgical as in kidney transplantation or pharmacological as by delivering ganglion blockers or a-adrenoceptor inhibitors for patients with hypertension, otherwise grave water and electrolyte imbalances may occur

Effect of renal ischemia / reperfusion [I/R] injury on glomerular filtretion rate [GFR] and tubular functions

Renal ischemia reperfusion [I/R] injury is of great clinical interest because of its role in renal failure, renal graft rejection and potential future chronic renal complications. Ten mongrel dogs were the material of the present study. Animals were subjected to renal ischemia by clamping the left renal artery for 30 minutes. After releasing the artery clamp six clearance periods [10 min each] were allowed to determine in each period glomerular filtration rate [GFR] by determining the inulin clearance [C[IN]], urinary flow rate [v], urinary excretion rate [UE] for Na[+], K[+], Cl[-],% Fractional excretion of sodium [%FE[Na]+], for both the ischemic left kidney and contralateral control kidney. The ischemic / control ratio [I/C] was determined for all the above parameters determined. v, UE[K+] decreased during the first collection period after reperfusion [10 min]. v increase markedly after that. GFR [C[IN]] and UE[K+] decreased also during the remaining 5 collection periods [50 min]. UE[Na+], UE[CI-] and FE[Na]% increased dramatically allover the collection periods [60 min]. The mechanisms of these changes were discussed. Gradual renal reperfusion and pre and post administration of antioxidants and anti-inflammatory drugs are recommended to ameliorate the deleterious affects ofl/R on the structure and function of the kidney

Pathophysiological effects of mobile phone radiations on the brain: an experimental study

The increased use of mobile phone worldwide has focused interest on the possible effects of radiofrequency fields on health. However, until now no satisfactory mechanism has been proposed to explain the biological effects of these radiations. Thus this study was undertaken in order to investigate the effect of radiations emitted from mobile phone on: Malonyldialdehyde [MDA], as a lipid peroxidation product, and serotonin concentrations, as well as the activities of acetylcholinesterase [AChE] and sodium-potassium ATP-ase [Na[+] K[+] ATP-ase] enzymes in the different parts of rats brain. The study was conducted on twenty adult male albino rats. Ten were exposed to radiations emitted from cellular phone [the experimental group] and ten rats were in the same exposure conditions but the mobile phone was turned off [the control group]. Na[+] K[+] ATP-ase enzymatic activity was significantly lower while MDA and serotonin concentrations were significantly higher in all studied brain parts of the experimental group. AChE was found to be significantly lower only in the cerebellum of the experimental group. These results support the interaction of radiofrequency fields of mobile phones with biological systems. Oxidative stress and diminished Na[+] K[+] P-ase enzymatic activity in addition to disturbance in serotonergic neurons and possibly cholinergic neurons, all may play a role in the mechanism of adverse effects of electromagnetic radiations. Further studies are needed so as to find the threshold level for exposure to electromagnetic field [EMF] that is not adverse to human health

Association between serum OPG/s rankl system and leptin with aging in male rats

Increasing evidences have suggested the association between serum leptin and bone formation. Osteoprotegerin [OPG], an osteoblast derived regulator of bone resorption and formation binds with soluble receptor activator of nuclear factor Kappa beta ligand [sRANKL] on osteoclast surface -which binds to its cognate receptor RANK on the osteoclast precursor. Thus, OPG/RANKL/RANK system controls the balance in bone formation and resorption. This study is designed to evaluate whether the OPG/sRANKL system and leptin levels are modified with aging and how they are related to bone and aortic changes. Three groups of rats were selected according to age, 4 months old [Group I], 12 months old [Group II] and 24 months old [Group III]. Serum levels of OPG, sRANKL, leptin, calcium and phosphorus [in sera and aortic extracts] were determined. Histopathological examination of rat femur and aorta from each group was also done. ANOVA test revealed significant difference between the three groups. The aged group [Group III] had higher calcium levels in sera and aortic extracts, serum phosphorus, serum sRANKL, leptin with increased sRANKL/OPG ratio. However OPG was significantly decreased in the same group in comparison to the other 2 groups. A significant negative correlation between serum OPG and sRANKL/OPG ratio [r = -0.879, p < 0.001] and body weight [r = -0.763, p < 0.01] and positive correlation between leptin and sRANKL/OPG ratio [r = 0.734, p < 0.01] and Ca aortic extract [r = 0.844, p < 0.01]. The disruption of OPG/sRANKL system and leptin with old age due to deficient OPG, high serum sRANKL and leptin resistance would represent a link between arterial calcification and bone resorption that are mostly present in the elderly