Effects of steroids on calcium activated potassium channels and Essay

Effects of steroids on calcium activated potassium channels and secretion of LH and FSH in Atlantic cod (Gadus morhua) - Essay Example The secretion of these hormones by the gonadotropes is in turn mediated by the activity of gonadotropin releasing hormone (GnRH) produced by the BPG axis (Borg, 1994). Apart from regulating gametogenesis, these hormones also control steroidogenesis, a process that produces sex steroids involved in moderating gametogenesis (Schulz and Goos, 1999). Another important regulating hormone for the gonadotropins is dopamine, which has been reported as a down regulator in several teleost fish (Borg, 1994). The releasing hormone, GnRH, once produced binds and activates its receptors found on the membrane of the hormone producing cells of the pituitary gland (Bliss, Navratil, Xie, & Roberson, 2010). Contrastingly in teleost, there is a direct innervation of the pituitary gland by GnHR neurons, whereas, in humans and other mammals, the action of GnHR is via neurochemostasis (Mousa & Mousa, 2003). The binding of GnHR to its receptors on the gonadotropes triggers an increase in intracellular calcium ion concentration an action that stimulates the secretion of the hormones by the activated cells. The initial and immediate secretion of the hormones is by exocytosis of hormone vesicles, which is later followed by long term gene transcription to sustain prolonged secretions. The increase in calcium ion concentration is mediated by various mechanisms, such as an influx via voltage-gated channels, and release from intracellular stores. For example, action potentials tend to promote the influx of extracellular calcium ions in voltage-gated calcium ion channels expressing cells. The elevated calcium ions concentration, in the cells activates, calcium activated Potassium channels (CAPC), a pathway that plays a significant role in modulating membrane potentials and thus the electrophysiological effect on hypothalamic releasing hormones (Fettiplace & Fuchs, 1999). CAPCs are

Online Assingment Article Example | Topics and Well Written Essays - 500 words

Online Assingment - Article Example The New York Presbyterian hospital is the first hospital to test surgery that is designed only for type 2 diabetes. This study is designed to test if diabetes is better handled by surgery as opposed to the other medical treatment options that there are today. This is the first study available to those who are overweight or mildly obese and may open doors to new studies. Under guidelines that currently exist, bariatric surgery is used for the treatment of severe obesity or morbid obesity for people who have a body mass index of 35 or greater. Treatment is now available for patients with a body mass index as low as 26. The body mass index of a healthy person is 19 to 25 while those who are overweight have a body mass index of 26 to 29. Those who are obese have a body mass index that is above 30. Patients with a body mass index below 26 and above 35 are not permitted in the study because the health risks are too dangerous. Previous research has shown that gastric bypass surgery for thos e people with a body mass index of 35 or greater will benefit from the results to treat their type 2 diabetes.