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Studies on the motility of smooth muscles of the teats in lactating cows

Published online by Cambridge University Press:  01 June 2009

Jacques Bernabé  and
Georges Peeters
Jacques Bernabé
Affiliation:
Department of Physiology of the Veterinary Faculty, University of Ghent, Casinoplein 24, B-9000 Ghent, Belgium
Georges Peeters
Affiliation:
Department of Physiology of the Veterinary Faculty, University of Ghent, Casinoplein 24, B-9000 Ghent, Belgium
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Summary

Rhythmic motility of teats in lactating cows in vivo was studied by an improved plethysmographic technique. Oxytocin was infused intravenously and drugs were injected into the artery of the filled udder. The β-adrenergic agent, isoprenaline, induced relaxation of the teats whereas the α-adrenergic agents phenylephrine and noradrenaline, elicited contraction. In one animal however, noradrenaline always exerted a biphasic effect. Pre-treatment with propranolol, a β-adrenergic blocking agent, changed the biphasic effect into a purely activating response. Adrenaline, which exhibits both a and β effects, induced relaxation, but after propranolol treatment relaxation was abolished and even converted into contraction of the teat. It seems clear that both α and β adrenoceptors are present in longitudinal smooth muscles of the teats.

Milk losses as intermittent spurts were observed in several cows. Spurts occurred synchronously with rhythmical teat motility in the filled udder during oxytocin infusion. The intensity of milk leakage was increased by isoprenaline and inhibited by noradrenaline, indicating the presence of α and β receptors in teat sphincter muscles. Starting and stopping of milk spurts in correlation with rhythmical teat contractions were studied by audiovisual synchronization of video recording tape. The most common type of spurt began near the middle of the teat's relaxation phase and ended either just before or exactly at the beginning of the contraction phase. Interruption of the spurt is primarily due to closure of the streak canal.

Type
Original Articles
Information
Journal of Dairy Research , Volume 47 , Issue 3 , October 1980 , pp. 259 - 275
Copyright
Copyright © Proprietors of Journal of Dairy Research 1980

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References

REFERENCES

Bilék, J. & Janovsky, M. (1956). Nature 177, 582–583.CrossRefGoogle Scholar
Espe, D. (1946). Secretion of Milk. Ames, Iowa: The Iowa State College Press, 3rd Edn.Google Scholar
Espe, D. & Cannon, C. Y. (1942). Journal of Dairy Science 25, 155–160.CrossRefGoogle Scholar
Foust, H. L. (1941). Journal of the American Veterinary Medical Association 98, 143–149.Google Scholar
Manunta, G., Albergoni, V. & Pranzetti, P. (1962). Archivio Veterinario Italiano 13, 515–522.Google Scholar
Peeters, G. & De Bruycker, R. (1975). Journal of Dairy Research 42, 11–19.CrossRefGoogle Scholar
Peeters, G., Massart, L., Oyaert, W. & Coussens, R. (1948). Archives internationales de Pharmacodynamic et de Thérapie 75, 243–255.Google Scholar
Peeters, G., Petré, P. & Quintelier, W. (1977). Naunyn-Schmiedeberg's Archives of harmacology 296, 111–115.CrossRefGoogle Scholar
Pounden, W. D. & Grossman, J. D. (1950). American Journal of Veterinary Research 11, 349–354.Google Scholar
Sambraus, H. H. (1971). Zentralblatt fur Veterinärmedizin Reihe A 18, 335–340.CrossRefGoogle Scholar
Sisson, S. & Grossman, J. D. (1938). The Anatomy of the Domestic Animals, 3rd Edn. Philadelphia and London: W. B. Saunders Co.Google Scholar
Venzke, C. E. (1940). Journal of the American Veterinary Medical Association 96, 170–175.Google Scholar