Objectives—To determine uptake of β-carotene by
ovarian and uterine tissues and influence of dietary β-
carotene on steroidogenesis and production of uterine
protein during the estrous cycle in cats.
Animals—56 female cats.
Procedure—Cats were fed diets containing 0, 0.4, 2,
or 10 mg of β-carotene daily for 8 weeks prior to
detection of estrus. At time of observed estrus, all
cats were manually induced to ovulate. Blood samples
were obtained at estrus and every 2 days until
day 14 after ovulation. On that day, cats underment
laparotomy, and the ovaries and uterus were
removed. Uterine contents were flushed, and luteal
and endometrial tissues were obtained.
Results—Concentrations of β-carotene in plasma and
luteal and endometrial tissues increased in a dosedependent
manner. Concentrations of plasma progesterone
were higher between days 6 and 10 after
ovulation in cats fed diets containing β-carotene and
continued to increase through day 14 after ovulation
in cats fed a diet containing 10 mg of β-carotene.
Plasma concentration of estradiol-17β also was higher
between days 0 and 4 after ovulation in cats fed
diets containing β-carotene. Cats fed a diet containing
10 mg of β-carotene had the highest plasma estradiol
concentration. Total uterine protein concentration
was higher in cats fed β-carotene, compared with values
for cats fed an unsupplemented diet.
Conclusion and Clinical Relevance—Cats readily
absorb β-carotene. Increased concentrations of progesterone,
estradiol, and uterine protein may provide
more optimal ovarian function or a better uterine environment
for embryonic survival and development.
(Am J Vet Res 2001;62:1063–1067)