Abstract
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)