Other important explanation for decreased PR following resynchronization protocol is that 15-26% animals don't have functional luteal tissue
leading to suboptimal P4 in circulation (Silva et al., 2009; Sterry et al., 2006; Fricke et al., 2003).
Cut section showed placental tissue and blood clots grossly and were surrounded by ovarian stroma and some yellow corpus luteal tissue
. The fallopian tubes showed no evidence of any products of conception.
Total RNA Isolation and cDNA Synthesis.Total RNAwas extracted from luteal tissue
as described before using Qiagen's kit for total RNA extraction and purification (28704, Qiagen, Hilden, Germany) and DNA digested (RNase-free DNase Set, 50979254, Qiagen) according to the manufacturer's instructions.
Administration of GnRH on day 5 or 6 after estrus was found to alter follicular dynamics, induce luteal tissue
development and increase progesterone concentration upto day 13 resulting in better pregnancy rate (Arnett et al., 2002).
Acyclicity in these animals was confirmed by absence of luteal tissue
on ovaries by ultrasound scanning.
Prolactin has been shown to interact with LH in enhancing the secretion of progesterone in rat luteal tissue
Effect of dose of protaglandin [F.sub.2a] on steroidogenic components and oligonucleosomes in ovine luteal tissue
* The rise in progesterone levels during metestrus is a consequence of ovulation and subsequent transformation of tissue from ovulated follicles into luteal tissue
. These events are mediated by the LH surge.
Progesterone decreased for the two cycling cows when their luteal tissue
began to regress.
Gelatinases, endonuclease and Vascular Endothelial Growth Factor during development and regression of swine luteal tissue
. BMC Dev.
As previously mentioned (prior Section 2.1), eNOS protein was shown to be highly expressed in the mare early CL, when NO stimulated luteal tissue
for angiogenic factors production and induced bovine aortic endothelial cells (BAEC) proliferation (used as a model to assess angiogenic factors production by luteal cells).