Autocrine regulation of milk secretion by a protein in milk.
Frequency or completeness of milk removal from the lactating mammary gland regulates the rate of milk secretion by a mechanism which is local, chemical and inhibitory in nature. Screening of goat's milk proteins in rabbit mammary explant cultures identified a single whey protein of M(r) 7600 able to inhibit synthesis of milk constituents. The active whey protein, which we term FIL (Feedback inhibitor of Lactation), also decreased milk secretion temporarily when introduced into a mammary gland of lactating goats. FIL was synthesized by primary cultures of goat mammary epithelial cells, and was secreted vectorially together with other milk proteins. N-terminal amino acid sequencing indicated that it is a hitherto unknown protein. The evidence indicates that local regulation of milk secretion by milk removal is through autocrine feedback inhibition by this milk protein.
Wilde
C J
CJ
Hannah Research Institute, Ayr, Scotland, UK.
Addey
C V
CV
Boddy
L M
LM
Peaker
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002364:Caseins / Q000096:biosynthesis; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D006041:Goats; D007774:Lactation / Q000187:drug effects / Q000502:physiology*; D007785:Lactose / Q000096:biosynthesis; D008297:Male; D008321:Mammary Glands, Animal / Q000378:metabolism / Q000502:physiology; D008892:Milk / Q000378:metabolism*; D008894:Milk Proteins / Q000378:metabolism* / Q000494:pharmacology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011247:Pregnancy; D011817:Rabbits; D000067816:Whey Proteins
D002364:Caseins; D008894:Milk Proteins; D000067816:Whey Proteins; C114017:feedback inhibitor of lactation, Capra hircus; D007785:Lactose