The tachykinin peptide family

Health benefits of saliva: a review.

The tachykinin peptide family certainly represents one of the largest peptide families described in the animal organism. So far, more than 40 tachykinins have been isolated from invertebrate (insects, worms, and molluscs), protochordate, and vertebrate (skin, gastrointestinal tract, peripheral and central nervous system) tissues. Substance P (SP), first identified by bioassay as early as 1931 but sequenced only in 1971, several years after the elucidation of the structure of eledoisin from molluscan tissues and of physalaemin from amphibian skin, may be considered as a prototype of the tachykinins. Hitherto, as many as 19 tachykinins have been isolated from amphibian integument, and eight additional peptides have been isolated from amphibian gut and brain. Counterparts of skin tachykinins in mammalian tissues are SP, neurokinin A, and neurokinin B. Three main receptor subtypes for the tachykinins have been identified (NK1, NK2, and NK3), but their number is probably destined to increase. It is obvious that the peripheral and central effects of the tachykinins may substantially vary depending on the activation of different receptor subtypes. Matters are further complicated by the frequent capacity of the single tachykinins to bind, although with different affinity, to more receptors. It has been recognized that tachykinins have a variety of effects in physiological and pathological conditions, and there is evidence suggesting intrinsic neuroprotective and neurodegenerative properties of these neuropeptides. This review provides an update on the current body of knowledge regarding tachykinin occurrence and distribution in the animal kingdom, from the lowest invertebrates to man, and the physiological and pharmacological actions of tachykinins outlining the pregnant importance of this large peptide family.

The Tachykinin Peptide Family

Publisher Summary This chapter discusses the cell polyploidy and its relation to tissue growth and function. Cytophotometry established a fundamental similarity between polyploidy and polyteny, their common feature being multiple doubling of DNA in the cell. The occurrence and properties of polyploid cell populations is discussed. Polyploid nuclei have been found in protozoa and in the cells of many metazoa, both animals and plants. The common property of polyploid cell populations is retention of ability to reproduce DNA by differentiating and often fully differentiated cells. The stem cell phenomenon, which is clearly defined in many diploid cell populations, is in polyploid ones deprived of its main function being the only source of proliferation. The mode of polyploidy is briefly explained. Different types of mitotic polyploidization proper, complete abolition of the mitotic mechanism, and other cases of increases in the DNA content of cells are considered. The mechanism of supplanting mitotic syntheses by tissue-specific ones as the cause of reduction in the stages of mitosis may be common for different cell populations. But polyploidy in different tissues may have a different meaning associated with the specific function of the tissue. Polyploidization, as a rule, accompanies cell differentiation.

Cell polyploidy: its relation to tissue growth and function.

The chemical and physical basis for red wine astringency is reviewed. Models describing the physiological foundation of astringency are presented and compared. The phenolic and other red wine components that evoke astringency are described, together with their sensory properties and the factors that affect their perception. The paper also presents a detailed account of the chemical properties of saliva and the possible modes of interaction between these and red wine phenolics that lead to the necessary physical changes in saliva required to elicit astringency. Reasons for differences in astringency perception across oral sites and amongst individual tasters are also discussed. It is concluded that whilst great advances have been made in the field of red wine phenolic chemistry in recent years, a better understanding of the effect of wine polyphenol‐salivary protein interaction on the rheological properties of saliva is required in order to gain a comprehensive understanding of red wine astringency.

Red wine astringency: a review

Composition of saliva in mammalia

SummaryA diet of liquid ration (either Metrecal or liquid homogenized chow) caused atrophy of all major salivary glands in rats. No nutritional inadequacy accounted for the effects. The glands, as well as the acinar cells of these tissues, were markedly reduced in size; ducts were not appreciably altered. The parotid gland, the most affected of the 3, exhibited a decrease in amylase in the gland as well as in the secretion, but no appreciable change in concentration of Na and K in the secretion was noted. The functional and structural changes observed occur despite an intact innervation and suggest that activity of the glands, dissociated from neurotrophic influences, plays a major role in maintenance of gland integrity.

Salivary Gland Atrophy in Rat Induced by Liquid Diet.

SummaryElectrolyte composition ([K], [Na], [Cl], [HCO3]) and flow rate have been characterized in rat submaxillary saliva evoked by electrical stimulation of the sympathetic innervation. [K] and [H...

Role of β-Receptors in Sympathetic Regulation of Electrolytes in Rat Submaxillary Saliva.∗:

SummaryWhen stimulation of the rat parotid gland was effected by pilocarpine administration immediately following removal of one superior cervical ganglion, the amylase levels in the secretion obtained from the denervated gland were approximately 1/10 the levels obtained from the normally innervated gland, and were very similar to levels obtained as the result of stimulation of the auriculo-temporal nerve, or following administration of the β-adrenergic blocking agent Inderal prior to pilocarpine stimulation. On the other hand, amylase levels of pilocarpine-evoked saliva were not modified either by severing of the preganglionic fibers to the superior cervical ganglion or by removal of both adrenal glands. It is concluded that the sympathetic-like character of pilocarpine-evoked saliva results from an indirect stimulation of adrenergic receptors in the gland that is mediated through the superior cervical ganglion and the sympathetic postganglionic fibers.

Autonomic pathways involved in a sympathetic-like action of pilocarpine on salivary composition.

Stimulation of rat parotid gland by way of the auriculotemporal nerve was used to delineate the relationship between flow rate and concentration of Na and K in the saliva. It was found that [Na] in...

C. A. Schneyer

Papers

Composition of saliva in mammalia

Salivary Gland Atrophy in Rat Induced by Liquid Diet.

Role of β-Receptors in Sympathetic Regulation of Electrolytes in Rat Submaxillary Saliva.∗:

Autonomic pathways involved in a sympathetic-like action of pilocarpine on salivary composition.

Comparison of rat salivas evoked by auriculo-temporal and pilocarpine stimulation.