Xanthine oxidase/dehydrogenase in mammary gland of mouse: relationship to mammogenesis and lactogenesis in vivo and in vitro.
Xanthine oxidase/dehydrogenase (XO/XDH) increases at mid gestation in mammary gland but not in liver of the mouse and remains elevated until the pups are weaned at 20 d post partum. The increase in enzyme activity is due neither to alteration in activators or inhibitors nor to a production of a variant enzyme with altered catalytic properties. The increase is preceded in vivo by a surge of prolactin-like activity (placental lactogen) in plasma, and prolactin is required for induction of XO/XDH in explant culture in vitro. Induction of XO/XDH in vivo and in vitro precedes the full histological differentiation of the gland. In addition, induction of XO/XDH in vitro occurs more rapidly and at lower concentrations of prolactin than does histological differentiation. Thus although XO/XDH is present in milk, increased XO/XDH activity is an early event in mammogenesis in vivo and in vitro rather than a terminal component of differentiation.
Hayden
T J
TJ
Department of Zoology, University College Dublin, Belfield, Irish Republic.
Brennan
D
D
Quirke
K
K
Murphy
P
P
D000818:Animals; D046508:Culture Techniques; D005260:Female; D007774:Lactation; D008099:Liver / Q000201:enzymology; D008321:Mammary Glands, Animal / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D051379:Mice; D010928:Placental Lactogen / Q000097:blood; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011388:Prolactin / Q000097:blood / Q000494:pharmacology; D014968:Xanthine Dehydrogenase / Q000032:analysis*; D014969:Xanthine Oxidase / Q000032:analysis*
D011388:Prolactin; D010928:Placental Lactogen; D014968:Xanthine Dehydrogenase; D014969:Xanthine Oxidase