Abstract
The lipolytic response of isolated adipocytes from genetic obese (C57/BL/6J ob/ob)
and lean (C57BL/6J +/? ) mice to ACTH-(1-24), isoproterenol and glucagon has been
studied. The mean cell diameter of adipocytes from ob/ob mice was approximately twice
that of lean controls. The adipocytes from obese mice contained on the average approximately
six times the amount of triacylglycerol present in the smaller lean mouse adipocyte.
Lipolysis was calculated both on a per cell basis (105 cells) and per µ mole of triacylglycerol and when expressed on a cell number basis,
the larger adipocytes from obese mice showed an ACTH-(1-24) stimulated glycerol release
which was quantitatively similar to that of smaller adipocytes from lean mice. When
expressed per µ mole of triacylglycerol, the smaller cells from lean animals appeared
to be dramatically more responsive to either isoproterenol or ACTH-(1-24). On either
basis, ACTH-(1-24) stimulated glycerol release from obese mouse cells was greater
than the isoproterenol response. The obese mouse adipocyte showed selective loss of
response to isoproterenol compared to its lean control.
ACTH-(1-24) = corticotrophin-(1-24)-tetracosadecapeptide
Key words
Isolated Adipocytes - Obese Hyperglycemic Mice - Adrenocorticotrophin - Isoproterenol
- Glucagon - Cellularity