Role of renal sympathetic nerve activity in volatile anesthesia's effect on renal excretory function

Regulation of fluid balance is pivotal during surgery and anesthesia and affects patient morbidity, mortality and hospital length of stay. Retention of sodium and water is known to occur during surgery but the mechanisms are poorly defined. In this study, we explore how the volatile anesthetic sevoflurane influences renal function by affecting renal sympathetic nerve activity (RSNA). Our results demonstrate that sevoflurane induces renal sodium and water retention during pediatric anesthesia in association with elevated plasma concentration of renin but not arginine-vasopressin. The mechanisms are further explored in conscious and anesthetized ewes where we show that RSNA is increased by sevoflurane compared with when conscious. This is accompanied by renal sodium and water retention and decreased renal blood flow. Finally, we demonstrate that renal denervation normalizes renal excretory function and improves renal blood flow during sevoflurane anesthesia in sheep. Taken together this study describes a novel role of the renal sympathetic nerves in regulating renal function and blood flow during sevoflurane anesthesia.

THE ROLE OF THE KIDNEYS IN THE REGULATION OF THE ACID – BASE BALANCE OF THE BLOOD IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE

The aim: To study the regulation of acid-base balance and blood acid – renal excretory function in patients with COPD. Materials and methods: We examined 82 people, suggests that even during the most severe stages of COPD. Group 1 included 56 patients with COPD, group C. The average age was 60.54 + 2.04 years old, including 24 men and 32 women. The second group included 16 patients with COPD, group B, whose average age was 55.37 + 3.21 years old, including 7 men and 9 women. The third group included 10 healthy individuals, with an average age of 34.30 + 2.21 years, including 6 men and 4 women. Respiration function was evaluated on the basis of the forced expiratory curve recorded on a Spirolab II MIR S / N computer spirograph. The following indicators were evaluated: forced vital capacity (FVC), forced expiratory volume (FEV1) and FEV1 / FVC ratio. Results: For all patients with COPD there is a characteristic presence of acidosis (pH in patients with COPD group B – 7,34 ± 0,01, in patients with COPD group C – 7,31 ± 0,07). For patients with COPD group C there are pronounced respiratory disorders (pCO2 – 48,25 + 1,14 mm Hg, p02 – 28.07 +1.37 mm Hg). For patients with COPD group B characteristic metabolic disorders (BE--3,71 + 0,57), which increase as the disease progresses. For patients with COPD group C this figure is equal to 7.62 + 0.49. Thus, the analysis of indicators indicates the presence for all patients of mixed (respiratory and metabolic) acidosis, which increases as the chronic obstructive pulmonary disease progresses. Conclusions: There is activation of acid – renal excretory function and the inclusion of renal mechanisms in the regulation of acid-base balance.

Antihypertensive Effects of Gynura divaricata (L.) DC in Rats with Renovascular Hypertension

Gynura divaricata (L.) DC (Compositae) (GD) could be found in various parts of Asia. It has been used as a traditional medicine to treat diabetes, high blood pressure, and other diseases, but its effects have not yet been scientifically confirmed. Therefore, we aimed at determining whether GD could affect renal function regulation, blood pressure, and the renin-angiotensin-aldosterone system (RAAS). Cardio-renal syndrome (CRS) is a disease caused by the interaction between the kidney and the cardiovascular system, where the acute or chronic dysfunction in one organ might induce acute or chronic dysfunction of the other. This study investigated whether GD could improve cardio-renal mutual in CRS type 4 model animals, two-kidney one-clip (2K1C) renal hypertensive rats. The experiments were performed on the following six experimental groups: control rats (CONT); 2K1C rats (negative control); OMT (Olmetec, 10 mg/kg/day)-treated 2K1C rats (positive control); and 2K1C rats treated with GD extracts in three different doses (50, 100, and 200 mg/kg/day) for three weeks by oral intake. Each group consisted of 10 rats. We measured the systolic blood pressure weekly using the tail-cuff method. Urine was also individually collected from the metabolic cage to investigate the effect of GD on the kidney function, monitoring urine volume, electrolyte, osmotic pressure, and creatinine levels from the collected urine. We observed that kidney weight and urine volume, which would both display typically increased values in non-treated 2K1C animals, significantly decreased following the GD treatment (###p < 0.001 vs. 2K1C). Osmolality and electrolytes were measured in the urine to determine how renal excretory function, which is reduced in 2K1C rats, could be affected. We found that the GD treatment improved renal excretory function. Moreover, using periodic acid-Schiff staining, we confirmed that the GD treatment significantly reduced fibrosis, which is typically increased in 2K1C rats. Thus, we confirmed that the GD treatment improved kidney function in 2K1C rats. Meanwhile, we conducted blood pressure and vascular relaxation studies to determine if the GD treatment could improve cardiovascular function in 2K1C rats. The heart weight percentages of the left atrium and ventricle were significantly lower in GD-treated 2K1C rats than in non-treated 2K1C rats. These results showed that GD treatment reduced cardiac hypertrophy in 2K1C rats. Furthermore, the acetylcholine-, sodium nitroprusside-, and atrial natriuretic peptide-mediated reduction of vasodilation in 2K1C rat aortic rings was also ameliorated by GD treatment (GD 200 mg/kg/day; p < 0.01, p < 0.05, and p < 0.05 vs. 2K1C for vasodilation percentage in case of each compound). The mRNA expression in the 2K1C rat heart tissue showed that the GD treatment reduced brain-type natriuretic peptide and troponin T levels (p < 0.001 and p < 0.001 vs. 2K1C). In conclusion, this study showed that GD improved the cardiovascular and renal dysfunction observed in an innovative hypertension model, highlighting the potential of GD as a therapeutic agent for hypertension. These findings indicate that GD shows beneficial effects against high blood pressure by modulating the RAAS in the cardio-renal syndrome. Thus, it should be considered an effective traditional medicine in hypertension treatment.

Nephroprotective Effect of the Herbal Composition BNO 2103 in Rats with Renal Failure

(1) Background: this research aims at studying the nephroprotective properties of BNO 2103 in a model of chromate-induced renal failure in rats and at proving the possibility of using BNO 2103 in clinical practice for the complex treatment of chronic kidney disease (CKD). (2) Methods: fifty rats divided into five groups were studied. The drugs BNO 2103, Prednisolone and Lespephril were administered within 20 days. The excretory function and the functional state of kidneys, blood biochemical parameters and indicators of nitrogen metabolism were determined. (3) Results: under the influence of BNO 2103, there was a significant improvement in renal excretory function, in nitrogen metabolism and blood biochemical parameters compared with the control pathology group. BNO 2103 also outperformed the comparators in most indicators. (4) Conclusions: BNO 2103 has demonstrated nephroprotective, hypoazotemic and diuretic effects; and can be used to implement to the combined therapy of CKD.