The physiological role of luteinizing hormone-releasing hormone (LH-RH) in mediating the secretion of gonadotrophins is well established. However, administration of large doses of LH-RH produces a paradoxical anti-fertility effect. Thus, in women, agonists of LH-RH have been shown to inhibit ovulation (Nillius, Bergquist & Wide, 1978) and interfere with corpus luteum function (Casper & Yen, 197...

The relationship between embryo and corpus luteum was studied in an experiment on Barbari goats which were made unilaterally pregnant by embryo transfer 5 days after oestrus. Two embryos were transferred to each recipient whose luteal stage was coinciding with that of the donor. The site of transfer was either ipsilateral uterine horn (group I) or contralateral uterine horn (group II). The "ips...

The corpus luteum is a unique organ, which is transitory in nature. The development, maintenance and regression of the corpus luteum are regulated by endocrine, paracrine and autocrine signaling events. Defining the specific mediators of luteal development, maintenance and regression has been difficult and often perplexing due to the complexity that stems from the variety of cell types that mak...

Neat1 is a non-protein-coding RNA that serves as an architectural component of the nuclear bodies known as paraspeckles. Although cell-based studies indicate that Neat1 is a crucial regulator of gene expression, its physiological relevance remains unclear. Here, we find that Neat1 knockout (KO) mice stochastically fail to become pregnant despite normal ovulation. Unilateral transplantation of w...

The aim of this work was to study the influence of hypokinetic conditions on the ovary and corpus luteum of pregnant rats. The rats were kept in hypokinetic conditions for 5 days in the period between the 13th and 18th days of pregnancy. A three-dimensional reconstruction of the ovary and corpora lutea and also a stereological evaluation of the luteal cells and their nuclei were performed using...

Ovaries of lactating grey seals, which had been shot, were measured to obtain the size of each follicle and corpus luteum. Plasma samples were collected by temporarily immobilizing lactating females. The single corpus luteum regressed rapidly after pupping and circulating progesterone levels declined at parturition and remained low throughout most of lactation. A single wave of follicular growt...

The corpus luteum is an endocrine gland whose limited lifespan is hormonally programmed. This debate article summarizes findings of our research group that challenge the principle that the end of function of the corpus luteum or luteal regression, once triggered, cannot be reversed. Overturning luteal regression by pharmacological manipulations may be of critical significance in designing strat...

Chemerin, a chemokine, plays important roles in immune responses, inflammation, adipogenesis, and carbohydrate metabolism. Our recent research has shown that chemerin has an inhibitory effect on hormone secretion from the testis and ovary. However, whether G protein-coupled receptor 1 (GPR1), the active receptor for chemerin, regulates steroidogenesis and luteolysis in the corpus luteum is stil...

The human corpus luteum is a unique endocrine organ that is periodically constructed from the ovulated follicle. During human corpus luteum formation, which is well known as a pathophysiological model for tissue remodeling, the precise mechanisms by which centripetal vascular development is regulated remain unknown. Recently platelets were reported to contain chemoattractive substances with the...

The decline in pulsatile LH secretion and pituitary responsiveness to GnRH as pregnancy advances may be due to non-steroidal factors secreted by the ovine corpus luteum of pregnancy. Corpora lutea from ten ewes on days 70-80 of gestation were homogenized, charcoal-treated and, together with charcoal-treated follicular fluid from superovulated women, were subjected to inhibin immunoaffinity chro...