Differences in the amount of lipolysis induced by atrial natriuretic peptide in small and large adipocytes.
Atrial natriuretic peptide (ANP) is a 28-amino acid polypeptide that is primarily secreted by the heart. ANP is believed to be a hormone that regulates cardiovascular dynamics and renal functions; however, studies conducted in the past few decades revealed that ANP is also a potent lipolytic agent in human adipocytes that functions through the cGMP-dependent pathway. In this study, we separated human adipocytes within the same fat depot into small and large fractions using their floating properties and nylon filters of different pore sizes. Real-time PCR revealed that large adipocytes expressed higher mRNA levels of natriuretic peptide receptor (NPR)-A and hormone sensitive lipase, and binding studies showed that large adipocytes expressed more NPR-A on the membrane than small adipocytes. This finding was confirmed by the increase in the amount of glycerol that was released from adipocytes as the cell size increased. Taken together, these results clearly suggest that adipocyte size is an important determinant of ANP-stimulated lipolysis.
Yu
Jiahua
J
Department of Biochemistry, Medical School and Institute for Medical Sciences, Chonbuk National University, Jeonju, Jeonbuk, 561-756, Korea.
Yu
Hee-Chul
HC
Kim
Kyung-Ah
KA
Kwon
Kang-Beom
KB
Park
Jin-Woo
JW
Kim
Sung-Zoo
SZ
Kim
Suhn Hee
SH
Park
Byung-Hyun
BH
D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D000328:Adult; D000368:Aged; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001665:Binding Sites; D048429:Cell Size; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007457:Iodine Radioisotopes; D008066:Lipolysis / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D017461:Receptors, Atrial Natriuretic Factor / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D002787:Sterol Esterase / Q000235:genetics
D007457:Iodine Radioisotopes; D012333:RNA, Messenger; D009320:Atrial Natriuretic Factor; D002787:Sterol Esterase; D017461:Receptors, Atrial Natriuretic Factor; C091715:atrial natriuretic factor receptor A