Pattern of protein production by bovine corpora lutea during luteolysis and characterization of expression of two major secretory products of regressing corpora lutea.
Although the decrease of progesterone in serum and in luteal tissue during luteal regression is well characterized, relatively little is known about changes in proteins produced by the corpus luteum during this time. The first objective was to examine changes in patterns of protein secretion that might be associated with functional and structural luteal regression. The second objective was to characterize the expression of two major secretory products of regressing corpora lutea. Thirty normally cyclic heifers were randomly assigned at day 15-16 of the oestrous cycle (oestrus = day 0) to be ovariectomized at 0 h (no PGF2 alpha; n = 5) or at 4, 8, 12, 24 or 48 h after PGF2 alpha-induced luteal regression (n = 5 per time point). Total cellular RNA was isolated from tissue frozen at the time of ovariectomy. Thin slices (< 1 mm) of tissue were placed in methionine-deficient minimum essential media with [35S]methionine and placed in a humidified CO2 incubator at 38 degrees C. Media and tissues were collected 6 h later. Changes in profiles of secreted proteins were analysed by one-dimensional SDS-PAGE. A number of proteins (relative molecular mass ranging from 14,300 to 200,000) were produced by luteal tissue at each time point (0-48 h). The major secretory proteins had relative molecular masses of approximately 21,500, 28,200, 43,700 and 46,000. Secretion of the relative molecular mass 46,000 protein(s) increased (P < 0.05) between 4 and 24 h after PGF2 alpha injection compared with the 0 h group.(ABSTRACT TRUNCATED AT 250 WORDS)
Juengel
J L
JL
Department of Animal Sciences, University of Missouri, Columbia 65211.
Smith
G W
GW
Smith
M F
MF
Youngquist
R S
RS
Garverick
H A
HA
D000818:Animals; D002417:Cattle / Q000378:metabolism*; D003338:Corpus Luteum / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D015237:Dinoprost / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006023:Glycoproteins / Q000032:analysis; D003341:Luteolysis / Q000502:physiology*; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors; D010052:Ovariectomy; D014176:Protein Biosynthesis; D011506:Proteins / Q000032:analysis; D013997:Time Factors; D019716:Tissue Inhibitor of Metalloproteinase-2; D019714:Tissue Inhibitor of Metalloproteinases
D006023:Glycoproteins; D011506:Proteins; D019714:Tissue Inhibitor of Metalloproteinases; D019716:Tissue Inhibitor of Metalloproteinase-2; D015237:Dinoprost; D008666:Metalloendopeptidases