Opposite regulation of brain and C-type natriuretic peptides in the streptozotocin-diabetic cardiopathy

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Item Type:	Article
Title:	Opposite regulation of brain and C-type natriuretic peptides in the streptozotocin-diabetic cardiopathy
Creators Name:	Walther, T., Heringer-Walther, S., Tschoepe, R., Reinecke, A., Schultheiss, H.P. and Tschoepe, C.
Abstract:	C-type natriuretic peptide (CNP), a recent addition to the family of natriuretic peptides including atrial and brain natriuretic peptide (ANP, BNP), is believed to be an endothelium-derived vasodilator and to have an antimitotic effect. ANP and BNP concentrations are increased in conditions such as congestive heart failure, but cardiac CNP concentrations have not been investigated in this connection. Diabetes mellitus also involves myocardial dysfunctions without coronary artery disease or systemic hypertension. We therefore investigated the cardiac expression of CNP mRNA compared with that of BNP mRNA in streptozotocin (STZ)-diabetic rats. STZ- diabetic male Wistar rats (n=6) were studied in comparison with controls (n=6). The animals were characterized by their mean arterial blood pressure and plasma glucose concentrations. After extraction of total cardiac RNA, a specific cDNA probe of BNP was used for northern blot analysis, whereas myocardial CNP expression was analyzed by an RNase-protection assay. Twelve weeks after diabetes was induced, the rats were normotensive (96.4 ± 2.0 compared with 95.1 ± 1.9 mmHg) and hyperglycaemic (615 ± 61 compared with 165 ± 21 mg/dl; P<0.001). Left ventricular pressure was significantly impaired (76.8 ± 6.4 compared with 51.2 ± 3.6 mmHg). STZ-diabetic rats had a 3.2-fold increase in cardiac BNP expression compared with controls. In contrast, cardiac CNP mRNA concentrations were decreased 2.6-fold. CNP seems to be downregulated like other peptides with antimitotic and vasodilator activities (nitric oxide, prostacyclin, kinins). This may contribute to cardiac dysfunction in diabetes mellitus and suggests that stimulation of CNP expression could provide cardiac protection in such cases.
Keywords:	Brain, Brain Natriuretic Peptide, C-Type Natriuretic Peptide, Experimental Diabetes Mellitus, Heart Diseases, Messenger RNA, Streptozocin, Wistar Rats, Animals, Rats
Source:	Journal of Molecular Endocrinology
ISSN:	0952-5041
Publisher:	Society for Endocrinology
Volume:	24
Number:	3
Page Range:	391-395
Date:	1 June 2000
PubMed:	View item in PubMed

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