Metabolism in hypothermically perfused human kidney carcinoma: Incorporation rate of leucine into proteins

Abstract

Protein synthesis in tumour-involved human kidneys was studied before, during and after hypothermic perfusion. Before and after perfusion the incorporation rate of leucine into tumour and kidney cortex proteins was determined by incubation of tissue slices at 37 degrees C. During perfusion the incorporation of leucine from the perfusate into tumour and kidney cortex proteins was determined. Before hypothermic perfusion the incorporation rate of leucine into proteins at 37 degrees C was almost the same in kidney cortex and tumour. Leucine was incorporated linearly with time into kidney cortex and tumour proteins during hypothermic perfusion but the incorporation rate was 3-4 times higher into kidney cortex proteins than into tumour proteins. After 6 days of hypothermic perfusion the leucine incorporation rate into proteins at 37 degrees C was depressed by 50% in kidney cortex and by 90% in tumour tissue. The specific activity of leucine in the perfusate decreased during the perfusion period indicating a release of leucine from degradation of proteins. It is concluded that the effect of hypothermic perfusion on protein synthesis was more pronounced in the tumour than in the normal renal parenchyma.

Unraveling metabolism during kidney perfusion using tracer studies: a systematic review

“…In five studies (5/30, 17%), the different groups did not have similar baseline characteristics or analyses were not adjusted for confounders 35,38,48,51,55 . Performance bias was rated as high in three studies, 31,34,40 low in one study, 42 and unclear in all others (26/30, 87%) 27–30,32,33,35–39,41,43–55 . Random housing of animals was not performed in two studies (2/30, 7%) 31,40 and was not reported in the remaining studies 27–30,32–39,41–56 .…”

“…Kidneys were retrieved from rats (21/30, 70%), rabbits (2/30, 7%), dogs (4/30, 13%), and more recently from pigs (3/30, 10%). A perfusion device, allowing ex situ kidney perfusion was used in all but four cases 27–51 . In the latter, the kidney was perfused in situ 52–54 or the perfusion method was unclear 55 .…”

“…The risk of bias was assessed as “unclear” because essential information was often not reported (Figure 3, Tables S3 and S4). The risk of selection bias remained unclear for the majority of studies (21/30, 70%) 27–30,32–34,36,37,39,41,43–47,49,52–54 and could be rated as low in two studies 42,50 and high in seven 31,35,38,40,48,51,55 . Group allocation was not reported in 25 studies (25/30, 83%) 27–30,32–37,39,41,43–49,51–56 .…”

“…The risk of detection bias was unclear in most of the studies (23/30, 77%) 27–30,33,35–37,39,41,43–49,51–56 . A low risk was found in the two recent studies 42,50 whereas five older studies 31,32,34,38,40 were deemed to have high risk because outcomes were not assessed randomly (5/30, 17%) 31,32,34,38,40 or the outcome assessor was not blinded (2/30, 7%) 31,40 . The risk of attrition bias was high in 18 studies (18/30, 60%), 27–30,35,37,38,40,43,45–49,51,53,55,56 low in two studies (2/30, 7%) 33,36 and unclear in the others (10/30, 33%) 31,32,34,39,41,42,44,50,52,54 .…”

“…A low risk was found in the two recent studies 42,50 whereas five older studies 31,32,34,38,40 were deemed to have high risk because outcomes were not assessed randomly (5/30, 17%) 31,32,34,38,40 or the outcome assessor was not blinded (2/30, 7%) 31,40 . The risk of attrition bias was high in 18 studies (18/30, 60%), 27–30,35,37,38,40,43,45–49,51,53,55,56 low in two studies (2/30, 7%) 33,36 and unclear in the others (10/30, 33%) 31,32,34,39,41,42,44,50,52,54 . In 11/30 (37%) articles, outcomes were not reported selectively, reducing the risk of reporting bias 31,32,34,36,39,41,42,44,50,52,54 .…”