Chapters authored
Clinical Use of Progesterone and Its Relation to Oxidative Stress in Ruminants
Studies to determine the physiological effects and functions of progesterone started in the twentieth century. Progesterone is a steroid-structured hormone with 21 carbon atoms originating from cholesterol. The corpus luteum, formed after ovulation in ruminants, secretes progesterone, which plays a role in the continuity of the pregnancy. Progestagens can be used for estrus synchronization in cows and heifers. Similarly, they are used for estrus synchronization during the breeding season or outside the breeding season by taking advantage of the negative feedback effect of progesterone in small ruminants. It is applied for the treatment of embryonic deaths due to luteal insufficiency in cows with high milk yield. In anovulatory anestrus, exogenous progesterone applications can be very useful. Progesterone treatment contributes to the resolution of the anestrus by rearranging hypothalamic functions in cattle with follicular cysts. The oxidative stress index in the luteal phase, when progesterone is high in ruminants, is higher than in the follicular phase. In the critical period of pregnancy, a high index of oxidative stress-induced progesterone causes embryonic death. Factors that cause stress in high milk-yielding cows can affect the amount of progesterone synthesis by inhibiting luteal cell function due to excessive free radical production.
Part of the book: Sex Hormones in Neurodegenerative Processes and Diseases
Kisspeptin: Role in Female Infertility
Kisspeptin is a neuropeptide encoded by the kisspeptin gene (Kiss1) and located in different brain regions, primarily in the hypothalamus. Kisspeptin and its receptor G-protein-coupled receptor-54 (GPR54), are also found in behavioural brain regions such as the hippocampus and cortex. Kisspeptin, a very powerful neuropeptide that stimulates the secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary, does this by increasing gonadotropin-releasing hormone (GnRH) levels. In recent studies, it has been noted that kisspeptin is effective on reproductive functions. Globally 8 to 12% of couples have infertility problems, and the majority are residents of developing countries. Approximately 70% of infertility cases are caused by fertility problems in women. The frequency of infertility in women continues to increase every year and the underlying factors require further research. Bearing this problem in mind, this review examines the possible role of kisspeptin in female infertility. In doing so, it aims to find out how future application of kisspeptin may potentially unravel the neural reproductive disorder.
Part of the book: Reproductive Hormones