title: Cyclic nucleotide concentrations and protein kinase activities of bovine mammary tissue maintained in athymic nude mice: effects of mammogenic and lactogenic hormones.
abstract: Mammary tissue (4 x 4 x .3 mm) from five cows was placed subcutaneously in ovariectomized athymic nude mice. After 30 d mice were injected daily for 20 d with saline (controls), 17 beta-estradiol (1 microgram), progesterone (1 mg), or estradiol plus progesterone. Deoxyrobonucleic acid synthesis of bovine ductal epithelium was increased by estradiol, progesterone, or both. Cyclic 3',5'-adenosine monophosphate concentration of bovine mammary grafts was also increased by estradiol or progesterone. Estradiol increased cyclic 3',5'-adenosine monophosphate-dependent protein kinase activity and decreased cyclic 3',5'-guanosine monophosphate concentration in bovine mammary tissue. Progesterone decreased cyclic 3',5'-guanosine monophosphate-dependent protein kinase activity of bovine mammary tissue. In a second experiment, athymic nude mice bearing mammary tissue from five cows first received 20 d of pretreatment with saline or estradiol plus progesterone. Mice were then injected with saline or hydrocortisone (.2 mg/d) plus bovine prolactin (1 mg/d) for 2 d. Hydrocortisone plus prolactin enhanced alpha-lactalbumin production by bovine mammary tissue and had a greater effect in mice that had received estradiol plus progesterone. Pretreatment with estrogen plus progesterone increased tissue cyclic 3',5'-adenosine and monophosphate and cyclic 3',5'-adenosine monophosphate-dependent protein kinase and decreased cyclic 3',5'-guanosine monophosphate and cyclic 3',5'-guanosine monophosphate-dependent protein kinase. In mice that received estradiol plus progesterone, treatment with hydrocortisone plus prolactin decreased bovine mammary tissue cyclic 3',5'-adenosine monophosphate and cyclic 3',5'-adenosine monophosphate-dependent protein kinase but increased tissue cyclic 3',5'-guanosine monophosphate-dependent protein kinase.
authors.affiliation: Dairy Science Department, University of Wisconsin, Madison 53706.
authors.forename: L G
authors.initials: LG
authors.lastname: Sheffield
authors.forename: C W
authors.initials: CW
authors.lastname: Welsch
mesh_terms: D000818:Animals; D002417:Cattle; D000242:Cyclic AMP / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D008321:Mammary Glands, Animal / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism / Q000637:transplantation; D051379:Mice; D008819:Mice, Nude; D011374:Progesterone / Q000494:pharmacology*; D011494:Protein Kinases / Q000378:metabolism*
chemical_list: D011374:Progesterone; D004958:Estradiol; D000242:Cyclic AMP; D011494:Protein Kinases; D006152:Cyclic GMP