Quantitative and qualitative variation in the secretion of protein by the porcine uterus during the estrous cycle

• Published in: Biology of reproduction Vol. 7; no. 3; pp. 314 - 320
• Main Authors: Murray, F.A, Bazer, F.W, Wallace, H.D, Warnick, A.C
• Format: Journal Article
• Language: English
• Published: United States Society for the Study of Reproduction 01-12-1972
• Subjects: animal breeding; animal science; Animals; Chromatography, Gel; Electrophoresis, Polyacrylamide Gel; Estrus; Female; livestock; Molecular Weight; Pregnancy; Proteins - metabolism; Secretory Rate; Swine; Uterus - metabolism
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1093/biolreprod/7.3.314

The daily variation in protein content of porcine uterine flushings were studied on Days
2-18 and Day 20 of the estrous cycle. Average total protein per sample was relatively constant during the first 9 days of
the estrous cycle, but began to increase on Day 10. Maximum
total protein values were found on Day 15 after which the values decreased sharply to levels
on Days 17, 18, and 20 which were similar to those observed before Day 10 of the estrous
cycle. Sephadex G-200 gel filtration revealed three protein fractions (Fractions I-III) which
were present throughout the estrous cycle and had estimated molecular weights of greater
than 200,000, 200,000, and 90,000, respectively. Two additional protein fractions (Fractions
IV and V) were not present either before Day 9 or after Day 16 of the estrous cycle. Fraction
IV first appeared on Day 12 and had an estimated mol wt of 45,000. Fraction IV contained a
lavender protein which gave the uterine flushings obtained between Days 12 and 16 of the
estrous cycle a characteristic lavender color. Fraction V appeared as early as Day 9 and had
an estimated mol wt of 20,000. This study indicated that the protein milieu of uterine secretions changes quantitatively and
qualitatively during the estrous cycle.