Streptozotocin-induced diabetes decreases mammary gland lipoprotein lipase activity and messenger ribonucleic acid in pregnant and nonpregnant rats.
Diabetes mellitus is associated with a reduction of lipoprotein lipase (LPL) activity in adipose tissue and development of hypertriglyceridemia. To determine how a condition of severe insulin deficiency affects mammary gland LPL activity and mRNA expression during late pregnancy, streptozotocin (STZ) treated (40 mg/kg) and non-treated (control) virgin and 20 day pregnant rats were studied. In control rats, both LPL activity and mRNA were higher in pregnant than in virgin rats. When compared to control rats, STZ-treated rats, either pregnant or virgin, showed decreased LPL activity and mRNA content. Furthermore, mammary gland LPL activity was linearly correlated with mRNA content, and either variable was linearly correlated with plasma insulin levels. Thus, insulin deficiency impairs the expression of LPL in mammary glands, revealing the role of insulin as a modulator of the enzyme at the mRNA expression level.
Blanco-Dolado
Laura
L
Servicio de Bioquímica-Investigación, Hospital Ramón y Cajal, Madrid, Spain.
Martín-Hidalgo
Antonia
A
Herrera
Emilio
E
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology* / Q000235:genetics; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D007328:Insulin / Q000502:physiology; D008071:Lipoprotein Lipase / Q000235:genetics* / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000201:enzymology*; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000201:enzymology* / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D014158:Transcription, Genetic
D001786:Blood Glucose; D007328:Insulin; D012333:RNA, Messenger; D008071:Lipoprotein Lipase