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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-7-12
pubmed:abstractText
This study was designed to examine the role of insulin (INS) in regulating changes in lipid metabolism of larval and metamorphosing landlocked lamprey, Petromyzon marinus. Larvae and stage 6 metamorphosing individuals were injected intraperitoneally once per day for 2 days with either saline (0.6%), bovine INS (100 ng/g body weight), or alloxan (0.2 mg/g body weight). Insulin administration resulted in depressed plasma fatty acid (FA) levels, whereas alloxan injection elevated plasma FA levels at both life cycle intervals. In larvae, INS-induced hypolipidemia was attended by increased lipid concentration in kidney and muscle, reduced rates of lipolysis in kidney, liver, and muscle (as indicated by decreased triacylglycerol lipase activity), and, to a lesser extent, by higher rates of lipogenesis in kidney and muscle (as evidenced by higher acetyl-CoA carboxylase and/or diacylglycerol acyltransferase activities). In general, the effects of alloxan were opposite of those of INS. The alloxan-induced increase in plasma FA was supported by an enhanced rate of lipolysis in the kidney, a relatively lower rate of fatty acid synthesis in kidney, liver, and muscle, and a relatively lower renal rate of TG synthesis. In stage 6 metamorphosing lamprey, the INS-induced decline in plasma FA was attended by reduced renal and hepatic rates of lipolysis and by enhanced lipogenesis, as indicated by increased renal and hepatic rates of de novo fatty acid synthesis and hepatic and muscular rates of TG synthesis. In contrast, the increase in plasma FA induced by alloxan in stage 6 animals was supported by reduced TG synthesis in liver. Immunocytochemistry revealed that alloxan was not cytotoxic to pancreatic beta cells, suggesting that the effects of alloxan were extrapancreatic in the time frame of our study. Because insulin-induced lipogenesis and antilipolysis is similar to the pattern of lipid metabolism (phase I) displayed by lamprey during their spontaneous metamorphosis, INS may play a role, possibly in concert with other factors, in coordinating metamorphosis-associated changes in lipid metabolism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0016-6480
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:volume
114
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
405-14
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Effects of insulin on lipid metabolism of larvae and metamorphosing landlocked sea lamprey, Petromyzon marinus.
pubmed:affiliation
Department of Zoology and Regulatory Bioscience Center, North Dakota State University, Fargo, North Dakota 58105-5517, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't