Efficient analysis of hepatic glucose output and insulin action using a liver slice culture system.
BACKGROUND
Liver slices have been reported to retain histological integrity and metabolic capacity for over 24 hours in flask culture systems, and they have been used for pharmacological and toxicological studies before. However, whether this method is suitable to measure hepatic glucose output is unknown.


METHODS
Precision-cut liver slices were prepared from fresh male rat liver. After high-glucose pre-incubation (11.2 mmol/l), medium was changed to low-glucose conditions (0.5 mmol/l). Glucose and lactate levels as well as aspartate aminotransferase activity were monitored for 50 minutes with or without addition of insulin (600 pmol/l) and/or epinephrine (0.5 micromol/l). Slice potassium content and histology were examined to prove liver viability.


RESULTS
We observed a stable glucose production from the liver slices of 0.3-0.4 micromol/g liver/min. Epinephrine increased (by 82+/-30%) and insulin decreased (by 80+/-8%) liver slice glucose output. Significant signs of ischemia were not detected.


CONCLUSIONS
Hepatic glucose release can be reliably measured in a liver slice culture system, and it is regulated by major hormone systems. This method may be helpful for further characterization of direct insulin action and resistance in a complex tissue as the liver; however, pharmacological applications such as the analysis of drug effects on hepatic glucose metabolism can also be envisioned.
Buettner
R
R
Department of Internal Medicine I, University of Regensburg, Germany. roland.buettner@klinik.uni-regensburg.de
Straub
R H
RH
Ottinger
I
I
Woenckhaus
M
M
Schölmerich
J
J
Bollheimer
L C
LC
D000818:Animals; D004837:Epinephrine / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D007333:Insulin Resistance; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009924:Organ Culture Techniques / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D013566:Sympathomimetics / Q000494:pharmacology
D007004:Hypoglycemic Agents; D007328:Insulin; D013566:Sympathomimetics; D006003:Glycogen; D005947:Glucose; D004837:Epinephrine