Friederike Mueller1, Johanna Katharina Teloh-Benger1, Bjoern Hussmann2, Sven Lendemans3, Indra Naemi Waack4. 1. Institute of Physiological Chemistry, University of Duisburg-Essen, University Hospital Essen, Essen, Germany. 2. Department of Special Trauma Surgery, Alfried Krupp Hospital Essen-Ruettenscheid, Essen, Germany. 3. Department of Special Trauma Surgery, Alfried Krupp Hospital Essen-Ruettenscheid, Essen, Germany; Department of Trauma and Orthopedic Surgery, Alfried Krupp Hospital Essen-Steele, Essen, Germany. 4. Institute of Physiological Chemistry, University of Duisburg-Essen, University Hospital Essen, Essen, Germany. Electronic address: indra.waack@uk-essen.de.
Abstract
BACKGROUND: In the past, protective effects in terms of prolonged survival of malate-containing solutions were demonstrated in the treatment of experimental hemorrhagic shock (HS). The objective of the present study was to investigate malate's impact on the kidneys. Therefore, renal function and morphological and histological anomalies were examined. MATERIALS AND METHODS: Male Wistar rats were subjected to severe HS by dropping the mean arterial blood pressure to 25-30 mmHg. The depth was held for 60 min. Subsequently, reperfusion with Ringer's solution or a 10 mM malate-containing solution was performed both together with blood in a 2:1 relation, followed by an observation period of 150 min. RESULTS: Compared with the control group (Ringer's solution), malate increased diuresis and, thus, enhanced excretion of creatinine and urea. Shock-induced histopathological changes were reduced by malate administration. Renal hemorrhages in the straight proximal tubule and in the distal tubule were reduced and even significantly reduced in the proximal convoluted tubule. Malate significantly preserved the endothelial glycocalyx in the proximal tubule. Surprisingly, malate induced glucosuria in the absence of a significant renal dysfunction, morphological damage, or hyperglycemia. CONCLUSIONS: The protective effect of malate observed in the treatment of severe HS in the rat may be explained by a certain protective effect of this substance for the kidney.
BACKGROUND: In the past, protective effects in terms of prolonged survival of malate-containing solutions were demonstrated in the treatment of experimental hemorrhagic shock (HS). The objective of the present study was to investigate malate's impact on the kidneys. Therefore, renal function and morphological and histological anomalies were examined. MATERIALS AND METHODS: Male Wistar rats were subjected to severe HS by dropping the mean arterial blood pressure to 25-30 mmHg. The depth was held for 60 min. Subsequently, reperfusion with Ringer's solution or a 10 mM malate-containing solution was performed both together with blood in a 2:1 relation, followed by an observation period of 150 min. RESULTS: Compared with the control group (Ringer's solution), malate increased diuresis and, thus, enhanced excretion of creatinine and urea. Shock-induced histopathological changes were reduced by malate administration. Renal hemorrhages in the straight proximal tubule and in the distal tubule were reduced and even significantly reduced in the proximal convoluted tubule. Malate significantly preserved the endothelial glycocalyx in the proximal tubule. Surprisingly, malate induced glucosuria in the absence of a significant renal dysfunction, morphological damage, or hyperglycemia. CONCLUSIONS: The protective effect of malate observed in the treatment of severe HS in the rat may be explained by a certain protective effect of this substance for the kidney.