Gonadotropin-releasing hormone

Introduction In vertebrates, reproduction is primarily controlled by the hypothalamus-pituitary-gonad axis. The gonadotropin-releasing hormone (GnRH) neurons in the hypothalamus are key regulators of the hypothalamic neuroendocrine system mainly though the synthesis of GnRH (Moenter et al., 2003). The decapeptide GnRH is released from the hypothalamus in a pulsatile manner, and the amplitude and frequency of these pulses change throughout the estrous cycle (McCartney et al., 2002; Moenter et al., 2003). High amplitude and low frequency pulses of GnRH secretion occur during the luteal phase of the estrous cycle with pulse frequency increasing and amplitude decreasing during the follicular phase (Savio et al., 1988; Clarke and Pompolo, 2005).…

synthetic decapeptide hormone which falls under the gonadotropin-releasing hormone agonist (GnRH agonist) utilized as the pamoates or acetate salts. GnRH is Triptorelin (GnRH) initiates persistent stimulation of the pituitary glands and therefore leads to a decline in the levels of follicle stimulating hormone (FSH) and gonatropins luteinizing hormone (LH) secreted by the pituitary gland. It achieves this function by over stimulating the body’s production of these hormones hence leading to a…

Puberty is considered to be a period of transition consisting of both physiological and morphological changes when an individual becomes a fecund adult from a juvenile. All mammals undergo puberty (1) although the precise timing of this event is different for each species. Pubertal onset, in mammals, is governed by the pulsatile release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. GnRH promotes secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from…

maintains blood glucose levels and other nutrients, oversees the functions of the reproductive system, controls contractions of the uterus during childbirth and stimulates breast milk, and aids in the effective of the immune system. The releasing and inhibiting hormones that are produced and released from hypothalamic neurons are the growth hormone-releasing hormone (GHRH), growth hormone-inhibiting hormone (GHIH), Thyrotropin-releasing hormone (TRH), Corticotropin-releasing hormone (CRH),…

synthesis B) increased T3/T4 synthesis C) increased body temperature D) decreased blood cholesterol levels E) increased lipolysis ____ 66. Increased levels of thyroid hormones would A) decrease basal metabolic rate. B) up regulate beta receptors C) impair body growth. D) decrease the effects of norepinephrine on the heart and blood vessels. E) decrease protein synthesis. ____ 67. Calcitonin A) is synthesized by the parathyroid glands. B) acts primarily on osteoblasts. C) decreases blood Ca2+…

A comparative study done by McGraw & Young (2010) used voles as subjects, because of their distinct social behavior. They showed that prairie vole pups, which are part of monogamous species, react to social isolation with ultrasonic calls as well as an increase in corticosterone level, which is a hormone involved in stress responses. On the other hand, montane vole pups, which are promiscuous species, did not respond to social isolation as a stressor, but on the contrary did produce ultrasonic…

many years in which many physical growth, sexual and psychological changes happen and therefore lead to a sense of maturity. A number of physiological changes occur as part of pubertal and biological development such as increases in individuals’ height, weight, body structure and organ systems (circulatory and respiratory). Hormonal activity is therefore what hugely influences these particular changes. Once puberty starts, hormones act as an organizational factor, hence preparing the body to act…

is the most beautiful and significant experience. The middle adulthood, is considered highly productive, especially in the intellectual and artistic sphere, and is ultimately the period in which full self-realization is achieved. In this period the cognitive development of the people are in their peak mental performance. Also, there are physical, psychological and social changes like menopause and andropause. The menopause cease and this is due to a change in the hormonal secretions of…

The nerve cell knows when to release a neurotransmitter after an electrical signal is triggered. Once the electrical signal is triggered the nerve cell will secrete a chemical, the neurotransmitter, which will diffuse across the synapse. The synapse is a compact space between the target cell and the nerve cell. Hormonal Signaling Endocrine cells secrete hormones into the blood vessel, which then send them to target cells. For any cell signaling and response to happen, a specific cell must send a…

Cells and cell networks can also adjust in response to external stimuli. For example, GnRH signaling in gonadotrope cells can cause actin reorganization, resulting in membrane projections and cellular migration towards blood vessels (70). Interestingly, pituitary cell networks can also exhibit sex differences. For example, a higher proportion of somatotrope cells respond to growth hormone releasing hormone (GHRH) in males than in females (71). It is possible that something similar may be…