The uptake of 14C-chloroquine by mouse pancreatic islets in vitro.
The uptake of 14C-chloroquine by isolated mouse pancreatic islets in vitro was investigated. The islets were found to have a very high capacity to accumulate the substance. The uptake of 14C-chloroquine in the islets was a saturable process. Metabolic inhibitors, ouabain, anaerobic conditions and absence of glucose did not inhibit the uptake of 14C-chloroquine in the islets, suggesting that the substance is accumulated by some means other than energy-dependent active transport or pinocytosis. The uptake of 14C-chloroquine was inhibited by low temperature and low pH and in the presence of mepacrine, chlorpromazine, imipramine and desmethylimipramine. Only a small part of the 14C-chloroquine which had been taken up in the islets left the cells during 45 min. incubation in non-radioactive media. Two possible mechanisms for the uptake of 14C-chloroquine in the islets are considered: (1) The accumulation may be due to a binding of the substance to cellular constituents. (2) Chloroquine may be trapped by protonation within lysosomes or other membrane-surrounded organelles with low pH.
D000042:Absorption; D000818:Animals; D002738:Chloroquine / Q000378:metabolism*; D002746:Chlorpromazine / Q000494:pharmacology; D003891:Desipramine / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007099:Imipramine / Q000494:pharmacology; D007515:Islets of Langerhans / Q000378:metabolism*; D008012:Lidocaine / Q000494:pharmacology; D051379:Mice; D009538:Nicotine / Q000494:pharmacology; D009584:Nitrogen / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D011796:Quinacrine / Q000494:pharmacology; D013696:Temperature
D010042:Ouabain; D009538:Nicotine; D002738:Chloroquine; D008012:Lidocaine; D011796:Quinacrine; D005947:Glucose; D009584:Nitrogen; D007099:Imipramine; D003891:Desipramine; D002746:Chlorpromazine