title: Renal effects of alpha-ketoglutarate early after coronary operations.
abstract: BACKGROUND
  Alpha-ketoglutarate (alpha-KG) is a Krebs cycle intermediate and the carbon skeleton of glutamate. Alpha-ketoglutarate has provoked interest in heart surgery because of its proposed critical role in myocardial metabolism. This study investigates the role of alpha-KG in renal function after cardiac surgical procedures.
  
  
  METHODS
  Twenty-two patients with normal preoperative renal function were included in a prospective, randomized, and controlled study. Eleven patients received intravenous infusion of 30 g alpha-KG/hour after the operation. Measurements were performed before operation, immediately after operation, and after 30 minutes of alpha-KG infusion.
  
  
  RESULTS
  Renal blood flow was higher during alpha-KG infusion, 297% +/- 97% (of preoperative value), than in controls, 125% +/- 20% (p < 0.05). Filtration fraction was lower (12.3% +/- 0.05% versus 17.2% +/- 1.1%, p < 0.01), which prevented a significant difference in glomerular filtration rate. The renal arteriovenous differences of lactate, glutamate, glutamine, and glycine changed toward a net release during alpha-KG infusion.
  
  
  CONCLUSIONS
  Infusion of alpha-KG enhances renal blood flow early after coronary surgical procedures in patients with normal renal function. The mechanism is unclear, but could be associated with primarily metabolic effects, and may potentially convey a beneficial effect for renal function.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Sahlgrenska University Hospital, Göteborg, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Jeppsson
authors.forename: R
authors.initials: R
authors.lastname: Ekroth
authors.forename: P
authors.initials: P
authors.lastname: Friberg
authors.forename: K
authors.initials: K
authors.lastname: Kirnö
authors.forename: I
authors.initials: I
authors.lastname: Milocco
authors.forename: F N
authors.initials: FN
authors.lastname: Nilsson
authors.forename: S
authors.initials: S
authors.lastname: Svensson
authors.forename: J
authors.initials: J
authors.lastname: Wernerman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures; D005919:Glomerular Filtration Rate; D005971:Glutamates / Q000097:blood; D005998:Glycine / Q000097:blood; D006801:Humans; D007656:Ketoglutaric Acids / Q000008:administration & dosage / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects*; D007773:Lactates / Q000097:blood; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012079:Renal Circulation / Q000187:drug effects
chemical_list: D005971:Glutamates; D007656:Ketoglutaric Acids; D007773:Lactates; D005998:Glycine