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Growth and Regression in Bovine Corpora Lutea: Regulation by Local Survival and Death Pathways
Author(s) -
Skarzynski DJ,
PiotrowskaTomala KK,
Lukasik K,
Galvão A,
Farberov S,
Zalman Y,
Meidan R
Publication year - 2013
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/rda.12203
Subject(s) - corpus luteum , luteolysis , luteal phase , endocrinology , medicine , biology , angiogenesis , ovulation , estrous cycle , luteinizing hormone , prostaglandin , follicular phase , ovary , hormone
Contents The bovine corpus luteum ( CL ) is a transient gland with a life span of only 18 days in the cyclic cow. Mechanisms controlling CL development and secretory function may involve factors produced both within and outside this gland. Although luteinizing hormone ( LH ) surge is the main trigger of ovulation and granulosa cells luteinization, many locally produced agents such as arachidonic acid ( AA ) metabolites, growth factors and cytokines were shown to complement gonadotropins action in the process of CL development. Bovine CL is a highly vascular gland, where the very rapid angiogenesis rate (until Day 5 of the cycle) results in the development of a capillary network, endowing this gland with one of the highest blood flow rate per unit mass in the body. Angiogenesis in the developing CL is later followed by either controlled regression of the microvascular tree in the non‐fertile cycle or maintenance and stabilization of the blood vessels, as seen during pregnancy. Different luteal cell types (both steroidogenic and accessory luteal cells: immune cells, endothelial cells, pericytes and fibroblasts) are involved in the pro‐ and/or anti‐angiogenic responses. The balance between pro‐ and anti‐angiogenic responses to the main luteolysin – prostaglandin F2α ( PGF 2α) could be decisive in whether or not PGF 2α induces CL regression. Fibroblast growth factor‐2 ( FGF2 ) may be one of the factors that modulate the angiogenic response to PGF 2α. Manipulation of local production and action of FGF2 will provide new tools for reproductive management of dairy cattle. Luteolysis is characterized by a rapid decrease in progesterone production, followed by structural regression. Factors like endothelin‐1, cytokines (tumour necrosis factorα, interferons) and nitric oxide were all shown to play critical roles in functional and structural regression of the CL by inhibiting steroidogenesis and inducting apoptosis.