Asian-Australasian Journal of Animal Sciences

Asian Australasian Association of Animal Production Societies (아세아태평양축산학회)
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Bioluminescent Determination of Lactose Secretion: A Measure of the In Vitro Performance of Mammary Acini from Lactating Rats

  • Choi, B.H. (Department of Animal Science, Chonnam National University) ;
  • Stewart, K.W. (The Waikato Polytechnic) ;
  • Davis, S.R. (AgResearch, Ruakura Research Centre) ;
  • Myung, K.H. (Department of Animal Science, Chonnam National University)
  • Received : 2001.07.07
  • Accepted : 2001.08.08
  • Published : 2002.02.01
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Abstract

A culture system for lactating rat mammary acini was evaluated, where the primary indicator of performance was lactose secretion, measured by a sensitive bioluminescence assay. Lactose secretion was reduced by half (p<0.01) over the first 6 h of culture by overnight feed withdrawal (FW) from tissue donors but was sensitive to increased glucose concentration in the culture media (p<0.001) up to 30 mM. Lactose production of cells from fed donors over the first 6 h in culture in 30 mM glucose was 8.9 fmol/cell/h - a rate calculated to be about half that in vivo. No significant difference was shown in lactose secretion by cells from fed or FW rats over 6-24 h. Lactose secretion was 3.6 fmol/cell/h by cells from fed animals in 40 mM glucose concentration media over the 6-24 h culture period. Addition of insulin to the culture media had no effect on rates of lactose secretion while addition of prolactin and hydrocortisone, with or without insulin, significantly (p<0.001) decreased lactose production over both 0-6 h and 6-24 h culture periods. Lactose synthesis in vitro was significantly enhanced by aeration of the media during collagenase digestion of mammary tissue (p<0.05). No improvement in lactose secretion was effected by shaking of cells during culture, Matrigel coating of culture dishes or change in cell density over a range up to 2.5 million cells per ml.

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References

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