Effect of in vivo and in vitro application of glucagon, insulin and epinephrine on Ca++-transport properties of liver mitochondria.
In vivo administration of glucagon, insulin or epinephrine, respectively, gives rise to an increase of Ca++-retention time as well as of the Ca++-uptake rate in subsequently isolated rat liver mitochondria. Whereas the changes of Ca++-transport properties after pretreatment with glucagon or epinephrine occur already 6--15 min after their administration, the effect of insulin is observed not earlier than 30 min after its application. Under diabetic and starving conditions the Ca++-retention time of isolated liver mitochondria is prolonged, whereas no alteration of the uptake rate occurs. Since alloxan as well as streptozotocin induced qualitatively similar changes, a specific action of alloxan on liver mitochondria can be ruled out. Application of insulin 60--90 min prior to decapitation normalizes the changes of mitochondrial Ca++-transport observed under chronic alloxan diabetic conditions. Cycloheximide abolishes the prolongation of Ca++-retention in mitochondria from alloxan diabetic rats, but has no influence on the changes induced by glucagon pretreatment.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism; D004837:Epinephrine / Q000494:pharmacology*; D005260:Female; D005934:Glucagon / Q000494:pharmacology*; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology*; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D013217:Starvation; D013311:Streptozocin / Q000494:pharmacology
D007328:Insulin; D013311:Streptozocin; D005934:Glucagon; D003513:Cycloheximide; D002118:Calcium; D004837:Epinephrine