luteinisierende

Luteinization refers to the ovarian process by which follicular cells transform into luteal cells after ovulation, leading to the formation of the corpus luteum. The term "luteinisierende" can describe the processes, stimuli, or cells involved in this transformation.

During the peri-ovulatory period, the midcycle surge of luteinizing hormone (LH) triggers luteinization. The theca interna and granulosa cells convert to two types of luteal cells: small and large luteal cells, collectively called granulosa lutein and theca lutein cells. They proliferate, acquire steroidogenic capacity, and secrete progesterone predominantly, with estrogen produced in smaller amounts. Cholesterol is transported into mitochondria via StAR protein to start steroidogenesis. The corpus luteum then forms and supports the luteal phase of the menstrual cycle.

Maintenance: In humans, the corpus luteum is maintained by LH in the early luteal phase and by human chorionic gonadotropin (hCG) if pregnancy occurs, which mimics LH. If pregnancy does not occur, luteolysis leads to regression of the corpus luteum around day 22–24, progesterone and estrogen decline, and menstruation ensues.

Clinical relevance: Luteinization is essential for establishing a receptive endometrium and early pregnancy. Abnormal luteinization can contribute to luteal phase defects, infertility, or anovulation. In veterinary medicine and research, luteinization is studied in the context of ovulation induction and assisted reproduction.