The metabolic effects of pokeweed mitogen in mice.
Lectins are a family of proteins that stimulate cellular responses after binding to carbohydrate chains on plasma membranes. In the study described here, a mixture of lectins--pokeweed mitogen (PKW)--was shown to have insulinomimetic effects in mice. After receiving PKW (15 mg/kg intraperitoneally [IP]), serum glucose declined from 154 +/- 3 to 23 +/- 10 mg/dL by 24 hours later. Anorexia developed, and by 3 days, there was a significant decline in body weight. Carcass weights were 10% lower, and epididymal fat pad weights were 45% lower. When given for 16 days, PKW 3 mg/kg every other day caused a sustained 10% weight loss. Severe combined immune deficiency (SCID) mice were sensitive to PKW, showing that B and T lymphocytes were not required for the effects to develop. Cytokine antagonists attenuated the hypoglycemia and anorexia, but only by 50%. Further study showed that PKW has insulin-like effects in vitro. Glucose uptake was stimulated when murine C2C12 myotubes were exposed to an enriched fraction of PKW. These results demonstrated that PKW has both insulin-like activity and weight-reducing effects when administered to mice. The development of therapy for adult-onset diabetes or obesity based on lectins from pokeweed may be possible.
Lazarus
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ProScript, Cambridge, MA 02139, USA.
Trimble
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Moldawer
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D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D001786:Blood Glucose / Q000032:analysis*; D002460:Cell Line; D016207:Cytokines / Q000037:antagonists & inhibitors; D003847:Deoxyglucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy; D004435:Eating; D007328:Insulin / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D016513:Mice, SCID; D009132:Muscles / Q000378:metabolism; D009765:Obesity / Q000188:drug therapy; D011043:Pokeweed Mitogens / Q000494:pharmacology* / Q000627:therapeutic use; D013601:T-Lymphocytes / Q000276:immunology; D015431:Weight Loss
D001786:Blood Glucose; D016207:Cytokines; D007328:Insulin; D008055:Lipids; D011043:Pokeweed Mitogens; D019344:Lactic Acid; D003847:Deoxyglucose