Nervous tissue physiological role

Among vertebrate species, the neuro-endocrine-immime system is responsible for many complex, inter-related physiological processes including neuronal, homeostatic, reproductive and immune functions. There are four main types of hormone polypeptides, eicosanoids, steroids and thyroid hormones. Reflecting the inter-dependency of the neiiro-endocrine and immune systems, hormones, neuropeptides and other neiirotransmitters are known to be produced by some immune cells and play a role in the regulation of the immune system, while endocrine and nervous tissues express receptors for many substances produced by the immune system. The major focus of interest in endocrine disruption has... 

In conclusion, the discovery of incretins has now come to an end in terms of therapeutic strategy of metabolic diseases since new medicines will be put on the market these coming years. However, a lot more needs to be done with regard to the physiological role of the hormones. Whereas the major filed of investigation for GLP-1 now relates to the effect of the peptide on the central nervous system and on (3-cell proliferation, for GIP it remains to understand its role in the numerous tissues where the corresponding receptor is expressed. 

Although many motor proteins are found in nervous tissue, there are few instances in which we hilly understand their cellular functions. The proliferation of different motor molecules and the existence of numerous isoforms raises the possibility that some physiological activities require multiple motors. There may be cases in which motors serve a redundant role to ensure that the physiological activity is maintained in the event of a loss of one motor protein. Finally, the existence of so many different types of motor molecule suggests that novel physiological activities requiring molecular motors may be as yet unrecognized. 

Abstract Quantitative receptor autoradiography methods have heen widely used over the last three decades to study the distribution and physiological role of a receptor in various tissues. This review provides an overview of in vivo and in vitro receptor autoradiography methods and their advantages as well as disadvantages in the study of receptors in the central nervous system. Comparison with immuno-histochemical and in situ hybridization methods is also highlighted in relation to the study of a given receptor in the nervous sytem. 

Although cells are the basic unit of the body, it is then-organisation into tissues that enables them to carry out their physiological roles. A tissue is an aggregate - a sheet or cluster - of similar cells that carry out one or more common functions. There are four basic types epithelial, connective, muscular and nervous. 

CNP consists of 22 amino acids (Figure 17-5). It is located predominantly in the central nervous system but is also present in several tissues including the vascular endothelium, kidneys, and intestine. It has not been found in significant concentrations in the circulation. CNP has less natriuretic and diuretic activity than ANP and BNP but is a potent vasodilator. Its physiologic role is unclear. 

P-Adrenergic receptors ((i-ARs) are members of the superfamily of G protein-coupled receptors that are stimulated by the catecholamines epinephrine and norepinephine (1). As part of the sympathetic nervous system, P-ARs have important roles in cardiovascular, respiratory, metabolic, central nervous system, and reproductive functions. Mice lacking one or more of the three p-AR subtype genes (P, p2, and p3) have been generated to elucidate the physiological role of individual subtypes. Moreover, cells and tissues extracted from these mice have been utilized as tools to understand the molecular and cellular basis of subtype-specific receptor function. These studies are summarized in this chapter. 

Vitamin B-12 coenzymes perform the following physiological roles at the cellular level, especially in the cells of the bone marrow, nervous tissue, and gastrointestinal tract... 

How is NAPE synthesized, and how is its biosynthesis controlled Unfortunately, we cannot satisfactorily answer this question at present. A calcium-dependent enzyme activity that catalyzes the transfer of fatty acyl groups from various donor phospholipids to PE, producing NAPE, has been partially characterized in dog brain tissue and in primary cultures of rat brain neurons.In these neurons, NAPE biosynthesis is stimulated by stimuli that elevate intracellular calcium levels and is potentiated by cAMP-dependent protein kinase activity. But the physiological roles, anatomical distribution and regulation of NAPE biosynthesis in the adult nervous system remain unknown. 

Histamine is a biogenic amine that is widely distributed in the body and functions as a major mediator of inflammation and allergic reactions, as a physiological regulator of gastric acid secretion in the stomach, as a neurotransmitter in the central nervous system (CNS) and may also have a role in tissue growth and repair. 

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