Matrix metalloproteinase-2 activity, protein, mRNA, and tissue inhibitors in small arteries from pregnant and relaxin-treated nonpregnant rats

• Published in: Journal of applied physiology (1985) 2006-06, Vol.100 (6), p.1955-1963
• Main Authors: Jeyabalan, Arundhathi, Kerchner, Laurie J, Fisher, Michelle C, McGuane, Jonathan T, Doty, Ketah D, Conrad, Kirk P
• Format: Article
• Language: English
• Subjects: Animals; Arteries - chemistry; Arteries - cytology; Arteries - physiology; Biological and medical sciences; Endothelium, Vascular - chemistry; Endothelium, Vascular - cytology; Endothelium, Vascular - physiology; Enzyme Activation - drug effects; Enzyme Activation - physiology; Female; Fundamental and applied biological sciences. Psychology; Inhibitor drugs; Matrix Metalloproteinase 2 - metabolism; Mesenteric Arteries - chemistry; Mesenteric Arteries - cytology; Mesenteric Arteries - physiology; Pregnancy; Pregnancy, Animal - physiology; Proteins; Rats; Relaxin - pharmacology; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; RNA, Messenger - genetics; Rodents; Tissue Inhibitor of Metalloproteinase-1 - analysis; Tissue Inhibitor of Metalloproteinase-2 - analysis; Tissue Inhibitor of Metalloproteinases - analysis; Vasodilation - drug effects; Vasodilation - physiology; Veins & arteries
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.01330.2005

1 Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine and Magee-Women's Research Institute, and 3 Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and 2 Department of Zoology and Howard Florey Institute, University of Melbourne, Parkville, Victoria, Australia Submitted 19 October 2005 ; accepted in final form 13 February 2006 Vascular gelatinase activity is essential for pregnancy- and relaxin (Rlx)-induced renal vasodilation and hyperfiltration in rats. The objective of this study was to further elucidate the mechanisms for the increase in vascular matrix metalloproteinase (MMP)-2 activity caused by pregnancy and Rlx. We first corroborated our earlier work by showing that pro- and active forms of MMP-2 were increased in small renal arteries from pregnant compared with virgin rats and Rlx-treated compared with vehicle-treated nonpregnant rats. We next investigated other artery types and showed that MMP-2 activity was upregulated in mesenteric arteries from pregnant rats (pro-MMP-2 by 50% and active MMP-2 by 40%, both P < 0.05) and from Rlx-treated nonpregnant rats (pro-MMP-2 by 50% and active MMP-2 by 90%, both P < 0.005) compared with their respective controls. To corroborate these results obtained by gelatin zymography, pro-MMP-2 protein was determined by Western analysis in the same small arteries. Pro-MMP-2 protein was increased in small renal arteries from pregnant compared with virgin rats and from Rlx- compared with vehicle-treated nonpregnant rats: pro-MMP-2-to- -actin ratio = 0.29 vs. 0.21 ( P < 0.01) and 0.43 vs. 0.32 ( P < 0.005). Findings were similar for mesenteric arteries. MMP-2 mRNA as measured by real-time PCR was increased in small renal arteries from pregnant and Rlx-treated nonpregnant rats compared with their respective controls. There were no significant differences in tissue inhibitor of metalloproteinase (TIMP-1 or TIMP-2) activity by reverse zymography in small renal arteries. Thus increases in MMP-2 mRNA and protein expression are major factors contributing to increased MMP-2 activity in small arteries from pregnant and Rlx-treated nonpregnant rats. gelatinase; pregnancy; vasodilation Address for reprint requests and other correspondence: K. P. Conrad, Magee-Women's Research Institute, 204 Craft Ave., Pittsburgh, PA 15213 (e-mail: rsikpc{at}mwri.magee.edu )