Luteinizing Hormone

Luteinizing Hormone is also known as gonadotropin, which is secreted by the anterior pituitary gland under the controlled action of a hypothalamic hormone called Gonadotropin-releasing hormone(GnRH). Follicle-stimulating hormone is another member of gonadotropins and is regulated by Gonadotropin-releasing hormone(GnRH). Both LH and FSH take action on gonadal activities of males and females and are called gonadotropins.

The action of Luteinizing Hormone on Males

Luteinizing Hormone controls the synthesis and secretion of a group of hormones, mainly testosterone, from the Leydig cells of testis in males. Testosterone is the primary sex hormone that initiates the primary role in developing male reproductive organs and helps increase muscle mass. Along with FSH, it helps in spermatogenesis. Any changes in LH and testosterone blood levels cause changes in the sexual personality of human males. Testosterone is an endocrine hormone, so after its secretion enters into the bloodstream through direct contact. The primary function of testosterone are as follows:-

• It helps in the development and maturation of male accessory reproductive organs.
• It helps in the role of spermatogenesis (production of sperms).
• It helps in the growth of muscle mass.
• It helps in the growth of facial hairs and axillary hairs.
• It helps maintain the male personality, like the low pitch of the vocal cord or aggressiveness.
• It acts on the central neural system and controls male sexual behavior (libido).

The action of Luteinizing Hormone on Females

Luteinizing Hormone helps in the development of immature follicles into mature Graafian follicles inside the ovary of females. After the formation of the Graafian follicle on the 14th day of the menstrual cycle called “LH surge,” where it helps in ovulation ( releasing the egg from the follicle) and helps in the conversion of the residual follicle into the corpus luteum. If pregnancy occurs, LH levels will decrease, and the total luteal phase is regulated by progesterone secreted by the corpus luteum. The primary function of LH in females are as follows:-

• It helps in the Follicular phase for the development of follicles which secretes oestrogens.
• It helps in the Ovulation of the mature egg on the 14th day.
• It maintains the corpus luteum in the luteal phase to secrete progesterone which helps retain the endometrium wall during pregnancy.
• It helps in the stimulation of oestrogens and progesterone production from the ovary.

The action of Luteinizing Hormone in another metabolism

Luteinizing hormone acts by restricting to a G-protein coupled receptor, which  initiates adenylyl cyclase. Adenylyl cyclase, a catalyst, then, at that point, produces cyclic-AMP, in this manner expanding its intracellular fixation, which then, at that point, actuates a kinase atom called protein kinase A (PKA). PKA then, at that point, phosphorylates explicit intracellular proteins that thus accomplish the end physiological activities of LH like steroid creation and ovulation. Androgens secreted by luteinizing hormones produce anabolic effects on protein and carbohydrate metabolism. LH also regulates the metabolism action of Phosphorylation within mitochondria of the steroidogenic cells of the ovary.

Conclusion

 Luteinizing hormone is secreted by the Gonadotrophic-releasing hormone (GnRH) from the hypothalamus, which is primarily responsible for maintaining male and female reproductive sex organs. In males, Luteinizing hormone secretes androgens which in turn plays basic role in overall development and maturation of testicles and maintain the male sexual behavior. In females, Luteinizing hormone secretes androgens which in turn plays a basic role in development of ovarian follicle and in ovulation and also helps in maintenance of pregnancy by secreting progesterone. This means that LH secretes androgens in both males and females but the action taking mechanism is different in both sexes. There is negative feedback and positive feedback mechanism that regulate the LH production from the hypothalamus.