Neuroendocrine Factors
Michael H. Stone, Timothy J. Suchomel, W. Guy Hornsby, John P. Wagle, Aaron J. Cunanan in Strength and Conditioning in Sports, 2023
Endocrine glands are stimulated by chemical substances (e.g., releasing factors or neurotransmitters). Stimulation subsequently leads to the secretion of a hormone, a process that has several characteristics including: Secretion occurs in very small amounts; many, if not all, endocrine glands release their hormones in a pulsatile fashion.The hormone has no effect on its secretory gland; only the target tissue is affected.The target tissues may be discrete or ubiquitous.Hormones may trigger alterations in the rate of biochemical reactions, which can persist even after the hormone has returned to baseline concentrations.
Prolactin and the Regulation if Secretion Including Membrane Flow: Potential Roles for Tubulin and Microtubules*
James A. Rillema in Actions of Prolactin on Molecular Processes, 1987
Few cellular processes integrate structure and function in the number and variety of ways as does secretion. Advances in almost any area of cell biology such as receptor physiology, membrane excitability, peptide synthesis, fluid and electrolyte transport, membrane-bound enzyme complexes, cell ultrastructure, energy metabolism, gene expression, motility and contractility, protein phosphorylation, calcium and cyclic nucleotide second messengers, etc. have found some application in the secretory process, thus accounting for rapid advances in our understanding. The Latin root for secretion means “to separate” and reflects the original concept of a process in which glands simply filter substances from the blood. We now know that most types of secretions are a mix of epithelial cell products synthesized de novo, and plasma substances transported across the epithelial sheet either transcellularly or between the cells, paracellularly. In exocrine cells, contributions may occur in gland regions where secretory cells are clustered into designated secretory sites (acini or alveoli) or along ducts.
Cystic Fibrosis
Stephen D. Litwin in Genetic Determinants of Pulmonary Disease, 2020
The pathogenesis of the disease is reasonably clear [3]. The most remarkable disturbance in pathophysiology lies in the behavior of the secretions from the exocrine glands. The mucous secretions are abnormally viscous; they obstruct the bronchi giving rise to pulmonary disease and the pancreatic ducts leading to pancreatic insufficiency. Hepatic cirrhosis, usually of the biliary type, intestinal obstruction caused by inspissated secretions, and other complications may arise. The only reliable biochemical abnormality is the increase in the sodium and chloride content of the sweat [3]. This is present from birth, continues throughout life, and is not related to the severity of the clinical disease [3-5]. The meconium [3,5] and electrolyte-sensitive electrode [4,6] tests used for diagnosis are both considered to be about 85% sensitive and 85-99% specific [7].
Modified mixed nanomicelles with collagen peptides enhanced oral absorption of Cucurbitacin B: preparation and evaluation
Published in Drug Delivery, 2018
Lan Tang, Lulu Fu, Zhuanfeng Zhu, Yan Yang, Boxuan Sun, Weiguang Shan, Zhenhai Zhang
The transport content has a linear relationship with the concentration and treatment time of the drug, whereas the carrier-mediated transport pathway possesses a non-linear relationship with these factors, and the transport quantity saturates at a given concentration. Therefore, the results from our study of the transmembrane transport behavior and absorption mechanism showed that the transport rate, apparent transport capacity, and apparent permeability coefficient of CuB-MMs-CPs nanomicelles were increased. Its absorption mechanism was also changed, in comparison to that of free CuB. The absorption of CuB was dominated by passive spreading and this occurred in a concentration-dependent manner. Due to the presence of the P-gp efflux effect, the P-gp inhibitor could significantly improve its absorption. The secretory process involved vector-mediated protein involvement, which required energy consumption and might be associated with interstitial protein mediation. The absorption of Cu-MMs-CPs nanomicelles was dominated by active transport, of which the carriers Labrasol and Korlliphor could effectively inhibit the P-gp efflux. The transport process required energy consumption, and its endocytotic proteins might be clathrin and caveolin. The secretion process was mainly controlled by changes in concentration.
Recent advances in our understanding of mast cell activation – or should it be mast cell mediator disorders?
Published in Expert Review of Clinical Immunology, 2019
Theoharis C. Theoharides, Irene Tsilioni, Huali Ren
Unfortunately, there are many confusing aspects both in the naming and diagnosis of such disorders. First, the term ‘activation’ is typically reserved for activation of receptors or enzymes while ‘stimulation’ is used for cells. Second, stimulation of mast cells may imply proliferation without secretion of all or even any mast cell mediators as in the case of mast cell sarcoma. Next, the term ‘secretion’ is usually reserved for mediators stored inside secretory granules, while the term ‘release’ is used for both pre-stored and newly synthesized mediators. Be it as it may, release of mast cell mediators can occur in many physiologic and pathologic settings. To make matters worse, there are a number of other diseases that mimic and/or are comorbid with diseases involving mast cells (Table 2). As a result, affected patients often go for 10–20 years and as many physicians of different specialties before a diagnosis is made, by which time they have been prescribed numerous medications, often with severe drug interactions that further complicate their presentation and course of their disease.
Surface properties of Enterococcus faecalis cells isolated from chicken hearts determine their low ability to form biofilms
Published in Biofouling, 2018
Jolanta Cieśla, Dagmara Stępień-Pyśniak, Agnieszka Nawrocka, Małgorzata Łukowska, Tomasz Hauschild, Andrzej Wernicki, Andrzej Bieganowski
Among the strains that were analysed, only E. faecalis (ATCC 29212) showed negative results for the β-galactosidase and lactose tests and, additionally, completely destroyed the blood cells (β-haemolysis). This is linked to the production and extracellular secretion of certain substances. One such substances is cytolysin/haemolysin, which displays both haemolytic and bactericidal activities towards a number of eukaryotic cell types, including macrophages and polymorphonuclear neutrophils, as well as Gram-positive bacteria (Libertin et al. 1992). Another substance, gelatinase, is an extracellular zinc endopeptidase that hydrolyses collagen, gelatine, and small peptides and has been shown to exacerbate endocarditis in an animal model. The production of these substances may potentially contribute to virulence in enterococci (Toğay et al. 2010).
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