Pregnancy recognition in cattle: effects of conceptus products on uterine prostaglandin production

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6695807

Knickerbocker, J J

In cattle, continued progesterone (P/sub 4/) production by the corpus luteum (CL) is required if pregnancy is to persist. Identification of putative conceptus-derived signals and evaluation of their biological roles relative to CL maintenance during early pregnancy were goals of this research endeavor. Using various chromatography systems, bovine conceptuses (days 19 to 23) exhibited extensive metabolism of tritiated P/sub 4/ (90-98%), in vitro. A majority of conceptus metabolites were 5..beta..-reduced pregnanes. A major conceptus metabolite was 5..beta..-pregnan-3..cap alpha..-ol-20-one (5..beta..-P). Conversely, endometrial explant cultures metabolized 40 to 50% of P/sub 4/ substrate to primarily 5..cap alpha..-reduced steroid products. An in vivo test system to evaluate uterine PGF/sub 2..cap alpha../ production capacity was characterized in experiment two. Exogenous estradiol-17..beta.. (E/sub 2/; 3 mg I.V.) stimulated uterine blood flow, and PGF/sub 2..cap alpha../ production and metabolism. In experiment three, CL function, interestrous interval, and spontaneous uterine PGF/sub 2..cap alpha../ production were evaluated in cyclic cows following intrauterine administration of 5..beta..-P, conceptus secretory proteins (CSP) or homologous serum proteins (Control). Results support a role for CSP in suppression of uterine PGF/sub 2..cap alpha../ production during early pregnancy in cattle.

• Research Organization: Florida Univ., Gainesville (USA)
• OSTI ID: 6695807
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BIOSYNTHESIS
CATTLE
DOMESTIC ANIMALS
FETUSES
HORMONES
IN VITRO
IN VIVO
ISOTOPE APPLICATIONS
KETONES
LABELLED COMPOUNDS
MAMMALS
METABOLISM
ORGANIC COMPOUNDS
PREGNANCY
PREGNANES
PROGESTERONE
PROSTAGLANDINS
RUMINANTS
STEROID HORMONES
STEROIDS
SYNTHESIS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES