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Transepithelial potential difference in the goat mammary gland and its change during hand milking, and administration of oxytocin and catecholamines

Published online by Cambridge University Press:  01 June 2009

Nikolaj P. Alekseev
Affiliation:
Laboratory of Pliysiology of Secretory Processes, Institute of Pliysiology, St Petersburg University, University Embankment 7/9, St Petersburg 199034, Russian Federation
Alexander G. Markov
Affiliation:
Laboratory of Pliysiology of Secretory Processes, Institute of Pliysiology, St Petersburg University, University Embankment 7/9, St Petersburg 199034, Russian Federation
Yuri A. Tolkunov
Affiliation:
Laboratory of Pliysiology of Secretory Processes, Institute of Pliysiology, St Petersburg University, University Embankment 7/9, St Petersburg 199034, Russian Federation

Summary

The reaction of secretory epithelium and myoepithelial cells in the alveoli to hand milking and i.v. injection of oxytocin and catecholamines was studied in lactating goats. The reaction of secretory cells was assessed by changes in the transepithelial (blood–milk) potential difference (PD), and the contractile reaction of myoepithelial cells by the growth of intramammary pressure (IP). The initial value of PD was 24·6 ± 0·6 mV, that of IP 3·32 ± 0·08 kPa (24·9 ± 0·6 mmHg). Milking and oxytocin administration caused a rise in PD and an increase in IP. After noradrenaline and adrenaline injections two-phase PD changes and a short-term rise in IP were recorded. Isoproterenol, a β-agonist, caused a rise in PD but did not affect IP. Phenylephrine, an α-agonist, caused two-phase and one-phase changes in PD. Simultaneously, a rise in IP was recorded. The results show that the reaction of the mammary gland to the substances administered is complex. Myoepithelial and secretory cells respond differently to short-term rises in the level of mediators and hormones in the blood.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1992

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References

REFERENCES

Blatchford, D. R. & Peaker, M. 1988 Effect of ionic composition of milk on transepithelial potential in the goat mammary gland. Journal of Physiology 402 533541CrossRefGoogle ScholarPubMed
Enomoto, K., Furuya, K., Maeno, T., Edwards, G. & Oka, T. 1987 Mechanically induced electrical responses in murine mammary epithelial cells in primary culture. FEBS Letters 223 8286CrossRefGoogle ScholarPubMed
Furuya, K. & Enotomo, K. 1990 Real-time imaging of intracellular calcium change with simultaneous single channel recording in mammary epithelial cells. Brain Research Bulletin 25 779781CrossRefGoogle ScholarPubMed
Furuya, K., Enomoto, K., Furuya, S., Yamagishi, S., Edwards, G. & Oka, T. 1989 Single calehimactivated potassium channel in cultured mammary epithelial cells. Pflügers Archiv European Journal of Physiology 414 118124Google Scholar
Grachev, I. I., Tolkunov, Yu. A. & Markov, A. G. 1978 [Effect of isadrine and propranolol on the membrane potential of mammary secretory cells.] Fiziologicheskiiˇ Zhurnal SSSR imeni I.M. Sechenova 64, 309314Google Scholar
Linzell, J. L. & Peaker, M. 1971 a Intracellular concentrations of sodium, potassium and chloride in the lactating mammary gland and their relation to the secretory mechanism. Journal of Physiology 216, 683700Google Scholar
Linzell, J. L. & Peaker, M. 1971 b Mechanism of milk secretion. Physiological Reviews 41, 564597Google Scholar
Mosdol, G., Sjaastad, Ø. V. & Blom, A. K. 1981 Plasma concentrations of oxytocin and intramammary pressure in goats during manual stimulation of the udder and hand-milking. Journal of Endocrinology 90 159166CrossRefGoogle ScholarPubMed
Peaker, M. 1977 Mechanism of milk secretion: milk composition in relation to potential difference across the mammary epithelium. Journal of Physiology 270 489505CrossRefGoogle ScholarPubMed
Peaker, M. 1980 The effect of raised intramammary pressure on mammary function in the goat in relation to the cessation of lactation. Journal of Physiology 301 415428CrossRefGoogle Scholar
Tolkunov, Yu. A. 1989 a [lon-dependent hyperpolarization changes of membrane potential in secretory cells of the mammary gland.] Fiziologicheskiiˇ Zhurnal SSSR imeni I.M. Sechenova 75, 567574Google Scholar
Tolkunov, Yu. A. 1989 b [The membrane potential of the mammary gland secretory cells under the effect of mesaton and isadrine.] Fiziologicheskiiˇ Zhurnal SSSR imeni I.M. Sechenova 75, 14451451Google Scholar
Tolkunov, Yu. A. 1990 [The participation of the sodium and chloride ions in hyperpolarizational changes of the secretory cells membrane potential and in contractile responses of the mammary gland alveoli's myoepithelium.] Fiziologicheskiiˇ Zhurnal SSSR imeni I.M. Sechenova 76, 813819Google ScholarPubMed