n. 1. a yellow carotenoid pigment and potent *antioxidant found in many vegetables. Like the related pigment zeaxanthin (see also mesozeaxanthin), it occurs in high concentrations in the human eye. For this reason these pigments are thought to be crucial to healthy vision. 2. the yellow pigment of the corpus luteum.
(LH) This is a sugar-bearing protein manufactured by the anterior pituitary. Like a lot of the pituitary hormones, it surges on and off, since constant secretion would overload and deaden receptors. In women, it builds up after menses, stimulating the release of estrogen from the ovaries. Estrogen in turn stimulates the hypothalamus to increase its stimulation of LH from the pituitary, until, a day or two before ovulation, they produce a guitar-amp feedback, and the cells that produce LH start to surge follicle-stimulating hormone (FSH). The egg pops, being replaced by the corpus luteum, which produces progesterone for the next eleven to twelve days. Progesterone inhibits and lowers LH levels, as well as inhibiting levels of estrogen already being produced by the young follicles that will produce next month’s egg. In men, LH is responsible for stimulation of testosterone, although FSH and the testes hormone inhibin are responsible for both the production of sperm and controlling testosterone.... luteinizing hormone
(LH-RH) The same substance as Follicle-Stimulating-Hormone Releasing Hormone (FSH-RH), both of which are actually Gonadotrophin-Releasing Hormone (GnRH or GRH). Confused? Imagine being an endocrinologist 20 years ago. These (This) are (is) a peptide secreted into the little portal system that drains from the hypothalamus to the pituitary. If it is surged hourly and not too strongly, the pituitary secretes LH and the ovaries secrete estrogen. If it is surged hourly and strongly, the estrogens rise drastically, the pituitary secretes FSH, you pop an egg, start the corpus luteum and begin progesterone secretion. The surge is now slowed to every four or five hours, not too strongly, and the pituitary secretes LH every four or five hours...and the ovaries make progesterone. The same hypothalamic hormone triggers different pituitary responses based on AMPLITUDE and FREQUENCY.... luteinizing-hormone releasing hormone
A hormone secreted by the anterior PITUITARY GLAND which stimulates OVULATION, maturation of the CORPUS LUTEUM, and the synthesis of progesterone by the ovary (see OVARIES) and testosterone by the testis (see TESTICLE).... luteinising hormone
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