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Parotid secretion patterns during meals and their relationships to the tonicity of body fluids and to gastrin and pancreatic polypeptide in sheep

Published online by Cambridge University Press:  09 March 2007

Richard R. Carter ,
W. Larry Grovum  and
Gordon R. Greenberg
Richard R. Carter
Affiliation:
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario NIG 2W1, Canada
W. Larry Grovum
Affiliation:
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario NIG 2W1, Canada
Gordon R. Greenberg
Affiliation:
Faculty of Medicine, Clinical Sciences Division, University of Toronto, Ontario M5S 1A8, Canada
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Abstract

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The flow pattern of unilateral parotid saliva in sheep was compared when a total of 800 g lucerne (Medicago sativa) hay was offered as one, two, four or eight distinct meals. These patterns were related to changes in the tonicity of rumen fluid and plasma and to plasma concentrations of gastrin and pancreatic polypeptide. Sheep having ad lib access to hay overnight were offered fresh hay from 08.00 to 09.00 hours and were then given one, two, four or eight meals of fresh hay according to a schedule such that the mean deprivation period was 6.5 h for each meal frequency-size. Neither the peak in saliva flow rate nor the time of this peak differed among the different meal sizes. The flow rate decreased rapidly after reaching a maximum at 3.2 min into the meal. After 7 min of eating, the tonicity of plasma and rumen fluid had increased by only 2.2 and 8.2 mosmol/kg respectively. These increases would not cause the rapid decline in parotid flow observed after 3.2 min of eating. There was no postprandial change in the concentration of gastrin in jugular plasma. However, it did increase significantly (P = 0.0043) from 16 to 4 min before eating commenced. There was a postprandial peak in plasma pancreatic polypeptide concentration after 4.5 min of eating. However, the parotid flow rate remained low after the concentration of this peptide returned to prefeeding levels. The rapid decrease in parotid secretion rate observed early in the meal may be due to subsiding central excitation rather than to an inhibitory factor limiting production.

Keywords

GastrinPancreatic polypeptideSalivaSheep
Type
Feeding Behaviour and Metabolism
Information
British Journal of Nutrition , Volume 63 , Issue 2 , March 1990 , pp. 319 - 327
Copyright
Copyright © The Nutrition Society 1990

References

Bailey, C. B. & Balch, C. C. (1961). Saliva secretion and its relation to feeding in cattle. 2. The consumption and rate of secretion of mixed saliva in the cow during rest. British Journal of Nutrition 15, 383–402.CrossRefGoogle Scholar
Barnes, R. J., Comline, R. S. & Dobson, A. (1983). Changes in the blood flow to the digestive organs of sheep induced by feeding. Quarterly Journal of Experimental Physiology 68, 77–88.CrossRefGoogle Scholar
Bloom, S. R., Edwards, A. V. & Hardy, R. N. (1978). The role of the autonomic nervous system in the control of pancreatic endocrine responses to milk ingestion in the calf. Journal of Physiology 280, 37–53.CrossRefGoogle ScholarPubMed
Carr, D. H. (1984). The regulation of parotid and submandibular salivary secretion in sheep. Quarterly Journal of Experimental Physiology 69, 589–597.CrossRefGoogle ScholarPubMed
Carr, D. H. & Titchen, (1978). Post-prandial changes in parotid salivary secretion and plasma osmolality and the effects of intravenous infusions of saline solutions. Quarterly Journal of Experimental Physiology 63, 1–21.CrossRefGoogle ScholarPubMed
Carter, R. R. & Grovum, W. L. (1988). Reversible re-entrant cannulation of the parotid duct in sheep. Canadian Journal of Animal Science 68, 305–309.CrossRefGoogle Scholar
Carter, R. R., Grovum, W. L. & Bignell, W. W. (1985). Effect of tonicity in the contents of stomach and duodenum and in blood on parotid salivary secretion in sheep. Proceedings of the Nutrition Society 44, 137A.Google Scholar
Coats, D. A., Denton, D. A., Goding, J. R. & Wright, R. D. (1956). Secretion by the parotid gland of the sheep. Journal of Physiology 131, 13–31.CrossRefGoogle ScholarPubMed
Denton, D. A. (1957). A gregarious factor in the natural conditioned salivary reflexes of sheep. Nature 16, 341–344.CrossRefGoogle Scholar
Ekstrom, J., Brodin, E., Ekman, R., Hakanson, R., Mansson, B. & Tobin, G. (1985). Depletion of neuropeptides in rat parotid glands and declining atropine-resistant salivary secretion upon continuous parasympathetic nerve stimulation. Regulatory Peptides 11, 353–359.CrossRefGoogle ScholarPubMed
Grovum, W. L. (1988). Inserting a rumen cannula in sheep to minimize leakage. Canadian Journal of Animal Science 68, 561–563.CrossRefGoogle Scholar
Grovum, W. L. & Leek, B. F. (1988). Parotid secretion and associated efferent activity inhibited by pentagastrin in sheep. Peptides 9, 519–526.CrossRefGoogle ScholarPubMed
Hall, K. E., Greenberg, G. R., El-Sharkawy, T. Y. & Diamant, N. E. (1983). Vagal control of migrating motor complex-related peaks in canine plasma motilin, pancreatic polypeptide and gastrin. Canadian Journal of Physiology and Pharmacology 61, 1289–1298.CrossRefGoogle ScholarPubMed
Hansky, J., Reynolds, G. W., Stiffe, G. & Titchen, D. A. (1980). Pancreatic polypeptide secretion in sheep. Proceedings of the Australian Physiological and Pharmacological Society 11, 139P.Google Scholar
Hansky, J., Soveny, C. & Korman, M. G. (1972). Role of the vagus in insulin-mediated gastrin release. Gastroenterology 63, 387–391.CrossRefGoogle ScholarPubMed
Hill, K. J. (1965). Abomasal secretory function in sheep. In Physiology of Digestion in the Ruminant, pp. 221–230 [Dougherty, R. W., Allen, R. S., Burroughs, W., Jacobson, N. L. & McGilliard, A. D., editors]. Washington: Butterworths.Google Scholar
McLeay, L. M. & Titchen, D. A. (1970). Abomasal secretory responses to teasing with food and feeding in the sheep. Journal of Physiology 206, 605–628.CrossRefGoogle ScholarPubMed
Rehfeld, J. F. (1978). Localization of gastrins to neuro- and adenohypophysis. Nature 271, 771.CrossRefGoogle ScholarPubMed
Reid, C. W. S. (1986). Digestive physiology: The challenges today and tomorrow. In Control of Digestion and Metabolism in Ruminants, pp. 540–557 [Milligan, L. P., Grovum, W. L. and Dobson, A., editors]. Engelwood Cliffs: Prentice-Hall.Google Scholar
Reynolds, G. W., Stiffe, G. E., Hansky, J. & Titchen, D. A. (1978). Serum gastrin levels and abomasal secretion in response to feeding in sheep on restricted food intakes. Proceedings of the Australian Physiological and Pharmacological Society 9, 18P.Google Scholar
Reynolds, G. W., Stifle, G. E., Hansky, J. & Titchen, D. A. (1979). Serum gastrin and gastric secretion during insulin hypoglycaemia in sheep. Proceedings of the Australian Physiological and Pharmacological Society 10, 74B.Google Scholar
Shulkes, A. & Hardy, K. J. (1980). Effect of bombesin on pancreatic polypeptide secretion in sheep. Proceedings of the Australian Physiological and Pharmacological Society 11, 12P.Google Scholar
Taylor, I. L., Feldman, M., Richardson, C. T. & Walsh, J. H. (1978). Gastric and cephalic stimulation of human pancreatic polypeptide release. Gastroenterology 75, 432–437.CrossRefGoogle ScholarPubMed
Warner, A. C. I. & Stacy, B. D. (1977). Influence of ruminal and plasma osmotic pressure on salivary secretion in sheep. Quarterly Journal of Experimental Physiology 62, 133–142.CrossRefGoogle ScholarPubMed
Wilson, A. D. (1963). The effect of diet on the secretion of parotid saliva by sheep. II. Variations in the rate of salivary secretion. Australian Journal of Agricultural Research 14, 680–689.CrossRefGoogle Scholar