Primary hormone

The primary hormone responsible for conversion of glucose to glycogen is insulin (Figure 6.36). Insulin is secreted by special cells in the pancreas called the islets of Langerhans. Secretion of insulin is a response to increased glucose in the... 

The primary hormonal signals serve as extracellular signals that are interpreted by a signal transduction apparatus and turned into signals within the cell—these second messengers such as cAMP and fructose 2,6-bisphosphate warn individual enzymes within the cell about what s happening outside. 

In cells that synthesize epinephrine, the final step in the pathway is catalyzed by the enzyme phenylethanolamine /V-methyltransferase. This enzyme is found in a small group of neurons in the brainstem that use epinephrine as their neurotransmitter and in the adrenal medullary cells, for which epinephrine is the primary hormone secreted. Phenylethanolamine N-methyltransferase (PNMT) transfers a methyl group from S-adenosylmethionine to the nitrogen of norepinephrine, forming a secondary amine [5]. The coding sequence of bovine PNMT is contained in a... 

The bottom line for any of the above disorders is that insulin action is lost. Insulin is the primary hormone that regulates the metabolism of glucose in its conversion to the storage of carbohydrate—glycogen stored in the liver and muscles. Insulin also... 

Tay M-H, Kaufman DS, Regan MM, Leibowitz SB, George DJ, Febbo PG, Manola J, Smith MR, Kaplan ID, Kantoff PW, Oh WK. Finasteride and bicalutamide as primary hormonal therapy in patients with advanced adenocarcinoma of the prostate Ann Oncol 2004 15 974-8. 

The purpose of this chapter is to review the basic aspects of endocrine function, including the primary hormones and their effects. The factors regulating hormonal release and the cellular mechanisms of hormone action are also briefly discussed. Finally, the basic ways in which drugs can be used to alter endocrine function are presented. This overview is intend-... 

The thyroid gland synthesizes two primary hormones thyroxine and triiodothyronine. A discussion of the synthesis and function of these hormones follows. 

PTH works with two other primary hormones— calcitonin and vitamin D—in regulating calcium homeostasis. These three hormones, as well as several other endocrine factors, are all involved in controlling calcium levels for various physiologic needs. How these hormones interact in controlling normal bone formation and resorption is of particular interest to rehabilitation specialists. Regulation of bone mineral homeostasis and the principal hormones involved in this process are presented in the following section. 

Consequently, bone is a rather dynamic tissue that is constantly undergoing changes in mineral content and internal structure. The balance between bone resorption and formation is controlled by the complex interaction of local and systemic factors. In particular, several hormones regulate bone formation and help maintain adequate plasma calcium levels. The primary hormones involved in regulating bone mineral homeostasis are described below. 

With the availability of labeled hormones of high specific activity and the application of the principles of affinity chromatography, researchers were able to isolate cellular proteins that bind to plant hormones in vitro. Such proteins have been referred to as receptor proteins, binding proteins, or acceptor proteins. Tacit in the concept of hormone receptor proteins is the stereo-specific interaction of the hormone and the receptor protein (19). The resulting hormone-protein complex participates in growth processes that depend on new or enhanced protein synthesis. Advances in molecular biology and related sciences have enabled many researchers to study the role of receptors in the control of nuclear functions or other activities and to determine the site of primary hormonal action. 

C9. Chang, A., Yeap, B., Davis, T., Blum, R., Hahn, R., et al., Double-blind, randomized study of primary hormone treatment of stage D2 prostate carcinoma Flutamide versus diethylstilbestrol. J. Clin. Oncol. 14, 2250-2257 (1996). 

PTH and 1,25-dibydroxyvitamin D are the primary hormones regulating bone and mineral metabolism. Calcitonin has pharmacological actions, but a physiological role has not been established in adults. PTHrP is the principal mediator of hmnoral hypercalcemia of malignancy. 

The most striking fact revealed on this chart is that the isolation, structure, and partial synthesis of all of the primary hormones in each class, excepting aldosterone, were achieved concurrently within the 1930 s, a ten-year period. It would be tempting to assume from this table that structure determination and synthesis are routine consequences of the isolation. The isolations of this entire group, excepting aldosterone, occurred rather close together. However, the reasons which explain the... 

Together these three enzymes degrade the original molecule to glycerol and three unesterified fatty acids. In adipose tissue, the primary hormonal effects are mediated by epinephrine in stress situations and by glucagon during fasting. 

Some Primary Hormones of Interest and Their Actions... 

The adrenal medulla forms part of the sympathetic nervous system and is the primary site for the production of the catecholamines—epinephrine (adrenaline) and norepinephrine (noradrenaline), which are primary hormones (also called biogenic amines). The cells of the medulla are arranged in lobules and the medulla contains chromaffin cells, which are modified postganglionic cells of the sympathetic nervous system. The medulla produces catecholamines from tyrosine and their structures contain catechol and amine groups (Figure 10.3.3). 

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