Saliva and Salivation

Satellite Symposium of the 28th International Congress of Physiological Sciences, Székesfehérvár, Hungary, 1980

T. Zelles

• Publisher: Pergamon
• Year: 2013
• ISBN:
  9781483147536
• Topic: Medicina
• Subtopic: Enfermedades y alergias

Advances in Physiological Sciences, Volume 28: Saliva and Salivation covers the proceedings of the Saliva and Salivation satellite symposium, which is a pre-congress meeting connected to the 28th International Congress of Physiological Sciences. The book discusses a wide variety of studies that are relevant to the function of salivary system. This variety includes denervation as a method to produce a prolonged stimulation of salivary glands and reflex activation of the preganglionic fibers innervating the submandibular gland. This text also explains reflex discharge recorded from rat submandibular ganglion cells in vivo and effects of acetylcholine and adrenergic agonist on potassium transport in the salivary glands in vitro. This monograph will be of great interest to professionals and researchers, including dentists and zoologists, whose work concerns oral physiology.

DENERVATION AS A METHOD TO PRODUCE A PROLONGED STIMULATION OF SALIVARY GLANDS

N. Emmelin, Institute of Physiology, University of Lund, Sweden

Publisher Summary

This chapter discusses the role of denervation as a method to produce a prolonged stimulation of salivary glands. The chapter describes an experiment in which drops of saliva falling from cannulae in the two parotid ducts of an anaesthetized cat were marked on the smoked drum using an electron magnetic pen. The supersensitivity produced by the nerve section disappeared after repeated injections of pilocarpine or carbachol for two or three days, supporting the view that acetylcholine is of importance in the physiological control of the sensitivity of the glandular cells. The subsequent partial postganglionic denervation further raised the supersensitivity, but this was preceded by a temporary lowering of the level of sensitivity. This dip in the curve, which could be increased by injecting serine and prevented by injecting atropine during the period corresponding to the degeneration secretion, was at its lowest three days after the dissection of the chorda.

Some time after section of postganglionic autonomic nerves a period of activity in the denervated organ appears, called degeneration activity (see Emmelin and Trendelenburg 1972). This phenomenon is mainly due to a temporary increase in the release of the neurotransmitter into the junctional cleft. It was first observed in the parotid gland of the anaesthetized cat after section of the auriculo-temporal nerve (Emmelin and Strömblad 1958), which contains most of the parasympathetic postganglionic nerves of the gland (Ekström and Emmelin 1974). Fig. 1 shows an example of a degeneration secretion of parotid saliva, starting about 30 hours after denervation; such a flow continues for one day up to one and a half increasing gradually in rate to a maximumi then slowly declining. A similar secretion can be produced in the submandibular and sublingual glands; the difficulty in these cases is the brief postganglionic parasympathetic neurone, but a partial postganglionic denervation can be attained by tracing under the dissecting microscope the chorda into the hilum of the glands and cutting it as far distally as possible (Emmelin 1960, 1962). Parasympathetic degeneration secretion from the salivary glands has also been observed in dogs (Coats and Emmelin 1962a), rabbits (Ohlin 1963, Nordenfelt 1964) and rats (Delfs and Emmelin 1979). In glands well supplied with sympathetic secretory nerves a sympathetic degeneration secretion can be produced; the phenomenon can thus under favourable conditions be detected in the submandibular gland of the cat after removal of the superior cervical ganglion (Coats and Emmelin 1962b, Emmelin 1968a), and it can easily be obtained from this gland of the rat (Delfs and Emmelin 1974, Stefano et al. 1974, Almgren et al. 1976). The time scale of the phenomenon depends on many factors such as the anaesthesia and the type of nerve cut, sympathetic or parasympathetic. It varies with the species, as shown in Fig. 2, which schematically summarized observations on the parasympathetic degeneration secretion of submandibular saliva in four species. In the same gland of a certain species it varies with the level at which the postganglionic nerve is cut (Emmelin 1968b, Almgren et al. 1976). This is illustrated in Fig. 1, showing an experiment in which the auriculo-temporal nerve was cut on one side near its exit from the skull (proximally), on the other side close to the gland (distally). This experiment illustrates that the phenomenon can be made use of as an indicator to show when the degeneration of the nerve has reached a certain stage. In this case the importance of the length of the nerve stump left in connexion with the effector is demonstrated. In a similar way the degeneration secretion has been used to study effects of drugs on the progress of the nerve degeneration (Emmelin 1972, Almgren and Lundberg 1976, Arbilla et al. 1977, Perec et al. 1977). Particularly, however, the phenomenon seems useful for the following reason. Since the secretion is due mainly to an increased transmitter release which at a certain stage of the degeneration becomes supraliminal for activation of the effector, rises to a maximum and then slowly decreases and ceases as the process of degeneration proceeds, we are provided with a preparation where the effector cells for many hours, up to one or two days, depending on the gland and species chosen, are exposed to the physiological excitant in amounts sufficient to cause secretion, imitating prolonged nerve stimulation. Once the nerve has been cut this can take place in the anaesthetized or non-anaesthetized animal and even under in vitro conditions. The use of this preparation may be illustrated by the following four examples.

Fig. 1 Parotid degeneration secretion in a cat after section of the auriculo-temporal nerve, proximally on one side (P) and distally on the other (D). The numerals give the hour after denervation. Uppermost: minute marks. Drops of saliva falling from cannulae in the two parotid ducts of the anaesthetized cat were marked on the smoked drum using an electronmagnetic pen (Emmelin 1968).

Fig. 2 Submandibular degeneration secretion after partial parasympathetic denervation by dissection of the chorda tympani. The abscissa gives the time in hours after the operation. The beginning, maximum and end of the phenomenon in rats, rabbits, cats and dogs are shown schematically.

1 Control of the chemo-sensitivity of salivary glands

The supersensitivity to chemical excitants which gradually develops in e.g. the submandibular gland of the cat after section of the chorda-lingual nerve, a parasympathetic decentralization, can be further increased by the partial postganglionic denervation described above (Emmelin 1960). This is in agreement with “The law of denervation” (Cannon 1939). Supersensitivity of similar kind can be created by injections of atropine and other drugs with atropine action, repeated over two or three weeks, or by administration of botulinum toxin (Emmelin and Muren 1952, Emmelin 1961a). In the presence of atropine the supersensitivity can be demonstrated using for instance adrenaline as an excitant. This sensitization, produced by “pharmacological denervation” (Emmelin 1961b) was considerably larger than that caused by section of the chorda-lingual nerve, a decentralization, and also exceeded that seen after the surgical denervation; this seems reasonable in view of the fact that this latter denervation was far from complete. From these and other observations (Emmelin 1965) it has been concluded that supersensitivity develops in glands for some time deprived of some action of acetylcholine. To this action contributes not only acetylcholine released by impulses from the central nervous system, as shown when preganglionic fibres are cut, but in addition acetylcholine continuously released from the postganglionic neurones, as demonstrated by the increased effect of surgical or pharmacological denervation. The supersensitivity produced by nerve section disappears after repeated injections of pilocarpine or carbachol for two or three days, supporting the view that acetylcholine is of importance in the physiological control of the sensitivity of the glandular cells (Emmelin and Muren 1952). These drugs, which were given subcutaneously may, however, exert various actions, and in imitating the actions of acetylcholine on the gland they can obviously not distinguish between effects of transmitter released by nerve impulses and of acetylcholine randomly liberated even from a decentralized neurone.

Observations during parasympathetic degeneration secretion may throw some light on this question, since under those conditions the gland cells are exposed for a long period to increased amounts of acetylcholine released from the decentralized postganglionic neurone. Fig. 3 shows such an experiment on the submandibular gland of the cat (Emmelin 1964a). The sensitivity of the gland, expressed as the secretory response to a standard dose of adrenaline, was determined repeatedly in the course of two months using the following method (Emmelin 1964b). The cat was anaesthetized with ether followed by a short-acting barbiturate, which was given intracardially. The submandibular duct was cannulated from its orifice in the mouth, and secretory drugs were injected through the needle in the heart. This needle and the salivary cannula were then removed and the cat was left to wake up. In this way many observations could be made in the same animal with intervals of a few days. The sensitivity of the gland cells was ...

Table of contents

• Cover image
• Title page
• Table of Contents
• ADVANCES IN PHYSIOLOGICAL SCIENCES
• Copyright
• PREFACE
• INTRODUCTION
• IMPRESSIONS on the Saliva and Salivation Symposium (Székesfehérvár, 10–12 July, 1980)
• Chapter 1: DENERVATION AS A METHOD TO PRODUCE A PROLONGED STIMULATION OF SALIVARY GLANDS
• Chapter 2: REFLEX ACTIVATION OF THE PREGANGLIONIC FIBERS INNERVATING THE SUBMANDIBULAR GLAND
• Chapter 3: REFLEX DISCHARGES RECORDED FROM RAT SUBMANDIBULAR GANGLION CELLS IN VIVO
• Chapter 4: EFFECTS OF ACETYLCHOLINE AND ADRENERGIC AGONISTS ON POTASSIUM TRANSPORT IN THE SALIVARY GLANDS IN VITRO
• Chapter 5: ELECTROLYTE CONTENT OF PRIMARY AND FINAL SALIVA OF RABBIT MANDIBULAR GLANDS STUDIED IN VIVO
• Chapter 6: SECRETORY PROCESSES IN THE PERFUSED RABBIT MANDIBULAR GLAND
• Chapter 7: PHYSALAEMIN ACTION ON SALIVARY ELECTROLYTE TRANSPORT
• Chapter 8: DIRECT AND MODULATING SECRETORY EFFECTS OF SUBSTANCE P ON RAT SUBMANDIBULAR GLAND
• Chapter 9: RECEPTOR MECHANISMS INVOLVED IN STIMULUS-SECRETION COUPLING IN SALIVARY ACINAR CELLS
• Chapter 10: SOLUTION OF EPITHELIAL CELL MODELS FOR SECRETION AND ABSORPTION USING OPTIMIZATION ROUTINES
• Chapter 11: RELATIONSHIPS BETWEEN MINERALOCORTICOIDS AND Na+-K+-ATPase IN RAT SUBMANDIBULAR GLAND
• Chapter 12: THE ENERGETICS OF FLUID AND ELECTROLYTE SECRETION
• Chapter 13: SYNTHESIS, STORAGE, METABOLISM, RELEASE AND FUNCTION OF HISTAMINE IN THE CAT SUBMANDIBULAR GLAND
• Chapter 14: BLOOD FLOW IN THE SALIVARY GLANDS OF THE RAT
• Chapter 15: PERMEABILITY OF SALIVARY GLANDS TO MACROMOLECULES
• Chapter 16: VASCULARIZATION OF THE DEVELOPING RAT SUBMANDIBULAR GLAND
• Chapter 17: ULTRASTRUCTURAL SIGNS OF THE EARLY SALIVARY SECRETION IN CONNECTION WITH THE NERVE DEVELOPMENT IN THE RAT
• Chapter 18: HISTOCHEMICAL CHARACTERIZATION OF SALIVARY GLAND SECRETION
• Chapter 19: MORPHOLOGICAL CHANGES OF ACINAR CELLS IN THE SUBMANDIBULAR GLANDS OF MICE AFTER STIMULATION WITH AUTONOMIC DRUGS
• Chapter 20: MORPHOLOGY OF SECRETING SEROUS AND MUCOUS SUBLINGUAL GLAND CELLS OF THE MOUSE
• Chapter 21: QUANTITATIVE ULTRASTRUCTURAL CHANGES IN RAT PAROTID ACINAR CELLS AFTER LONG-TERM TREATMENT WITH SELECTIVE β-ANDRENOCEPTOR AGONISTS
• Chapter 22: DENSITY DISTRIBUTION OF THE SECRETORY GRANULES IN THE RAT PAROTID GLAND
• Chapter 23: PREPARATION OF ZYMOGEN GRANULES WITH GEL FILTRATION: DISTRIBUTION OF AMYLASE AND CARBONIC ANHYDRASE ACTIVITY FOLLOWING “LINEAR-DISCRETE” DENSITY GRADIENT CENTRIFUGATION
• Chapter 24: OSMOTIC PRESSURE AS A PRESUMABLE FACTOR INFLUENCING THE ZYMOGEN GRANULES IN THE PAROTID GLAND OF RATS
• Chapter 25: CONVERSION OF β-N-ACETYLHEXOSAMINIDASE B TO A BY GOLGI COMPLEX OF RAT PAROTID GLAND
• Chapter 26: CHARACTERISTICS OF SALIVARY α-AMYLASE OF THE MOUSE
• Chapter 27: INTERACTION OF CA2+ AND ADENOSINE 3′,5′-CYCLIC MONOPHOSPHATE DURING STIMULATION OF AMYLASE SECRETION FROM THE RAT PAROTID GLAND BY β-ADRENERGIC AGONISTS
• Chapter 28: AMYLASE SECRETION AND CYCLIC AMP-DEPENDENT PROTEIN PHOSPHORYLATION
• Chapter 29: CHANGES IN RAT PAROTID GLAND AMYLASE SECRETION AND cAMP LEVELS UNDER VARIED CONDITIONS OF β-ADRENOCEPTOR ACTIVITY
• Chapter 30: EFFECTS OF SUBSTANCE P RELATED PEPTIDES ON THE AMYLASE SECRETION IN RAT SALIVARY GLANDS
• Chapter 31: SALIVARY SECRETION OF FLUID AND AMYLASE IN THE PAROTID GLAND OF THE RABBIT AND THEIR DEPENDENCE ON TASTE AND CHEWING
• Chapter 32: REGULATION OF SUBLINGUAL (GLYCO)PROTEIN SECRETION IN THE MOUSE
• Chapter 33: NEURALLY REGULATED CHANGES IN ELECTROLYTE AND PROTEIN LEVELS OF RAT SALIVARY GLANDS DURING POSTNATAL DEVELOPMENT
• Chapter 34: AMYLASE SYNTHESIS IN THE PAROTID GLAND OF CORTISONE-TREATED RATS
• Chapter 35: EFFECT OF ESSENTIAL FATTY ACID DEFICIENCY ON ACYL GROUP COMPOSITION OF PLASMA MEMBRANES AND (Na+-K+)ATPase ACTIVITY OF SUBMANDIBULAR SALIVARY GLANDS IN RATS
• Chapter 36: CROSSED IMMUNOELECTROPHORETIC METHODS OF SEPARATION OF SALIVARY PROTEINS AT PHYSIOLOGICAL CONCENTRATIONS
• Chapter 37: GENETIC POLYMORPHISMS OF HUMAN PAROTID SALIVARY PROTEINS AND SALIVARY AMYLASE ISOZYME IN JAPANESE POPULATION
• Chapter 38: CHEMISTRY OF SALIVARY GLAND HORMONE
• Chapter 39: A MODEL FOR SALIVA-MEDIATED BACTERIAL AGGREGATION
• Chapter 40: FACTORS INVOLVED IN THE ADHERENCE OF SALIVARY PROTEINS TO HYDROXYAPATITE
• Chapter 41: THE SECRETION OF IONISED AND TOTAL CALCIUM, PROTEIN AND INORGANIC PHOSPHATE BY THE SALIVARY GLANDS OF RAT AND MAN
• Chapter 42: THE EFFECT OF PTH ON HUMAN PAROTID AND SUBMANDIBULAR SALIVA
• Chapter 43: EFFECTS OF PHYSIOLOGICAL VARIABLES ON THE CONCENTRATION OF CORTISOL IN HUMAN SALIVA
• Chapter 44: MANAGEMENT OF HEAD AND NECK IRRADIATED PATIENTS
• Chapter 45: PAROTID FLUID COMPOSITION IN HEALTHY AGING MALES
• Chapter 46: CHEMICAL COMPOSITION OF PAROTID SALIVA IN SJÖGREN’S SYNDROME
• Chapter 47: POSSIBLE ROLE OF PAROTID ADRENERGIC BETA-RECEPTORS IN SIALADENOSIS
• Chapter 48: SALIVA AND TASTE DISORDERS
• Chapter 49: THE ACTIVITY OF SOME SALIVARY ENZYMES OF THE RAT FED WITH A CARIOGENIC DIET AND WITH FLUORIDATION OF THE DRINKING WATER
• Chapter 50: HISTOPATHOLOGICAL STUDIES ON MESENCHYMAL TISSUES OF RAT TREATED WITH EXTRACTS FROM PAROTID GLANDS
• INDEX