Changes of messenger RNAs encoding vascular endothelial growth factor and its receptors during the development and maintenance of caprine corpora lutea.
The present study was conducted to examine changes of mRNAs encoding vascular endothelial growth factor (VEGF) and its receptors (KDR/Flk-1 and Flt-1), and CD34, which is known to be a specific marker for endothelial cells, during the development and maintenance of the caprine corpora lutea (CL). Effects of a potent GnRH antagonist (GA), which was previously shown to suppress release of luteinizing hormone (LH), on expressions of those mRNAs during the CL development were also investigated. Goats were divided into control (n = 12) and GA-treated groups (n = 6). The goats were treated with saline or GA (50 microg/kg, sc) on days 0 (day of ovulation), 4, and 8 (control only), and CL collected on a subset of goats (n = 3 for each day) on days 0 (no saline), 4, 8, or 14 (control only). Ribonuclease protection assay was performed to quantitate the mRNAs in the CL using specific cRNA probes generated by RT-PCR and in vitro transcription. Level of CD34 mRNA significantly increased from day 0 to 8 (CL development) in the control group (P < 0.05). Long and short forms were detected in the caprine CL by RT-PCR for VEGF mRNA and analyses of their sequences showed that they correspond to mRNAs encoding VEGF(165) and VEGF(121), respectively. Level of VEGF(165) mRNA significantly increased from day 4 to 8 and day 8 to 14 (CL maintenance) in the control group (P < 0.05) while VEGF(121) mRNA did not change during the whole period. Level of KDR/Flk-1 mRNA significantly increased from day 0 to 8 (P < 0.05) while Flt-1 mRNA significantly increased from day 8 to 14 (P < 0.005) in the control group. In the GA-treated group, levels of all of the mRNAs did not alter remarkably as compared with those in the control group. These results suggest that rise of KDR/Flk-1 and VEGF(165) mRNAs during the caprine CL development may be associated with enhanced angiogenesis and that increment of VEGF(165) and Flt-1 mRNAs during the CL maintenance may play nonangiogenic roles. The present study also indicates that the changes of VEGF(165) and KDR/Flk-1 mRNAs during the CL development are probably not regulated by LH.
Kawate
Noritoshi
N
Laboratory of Theriogenology, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan. nkawate@vet.osakafu-u.ac.jp
Tsuji
Makoto
M
Tamada
Hiromichi
H
Inaba
Toshio
T
Sawada
Tsutomu
T
D000818:Animals; D003338:Corpus Luteum / Q000378:metabolism*; D016228:Endothelial Growth Factors / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D006041:Goats; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D008222:Lymphokines / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor / Q000235:genetics*; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D012333:RNA, Messenger; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D040262:Receptors, Vascular Endothelial Growth Factor; D040301:Vascular Endothelial Growth Factor Receptor-2