CaBP9K Levels during the Luteal and Follicular Phases of the Estrous Cycle in the Bovine Uterus1

Abstract

The expression of calbindin-D9K (CaBP9K) and calbindin-D28K (CaBP28K) genes in the reproductive system is well established for rodent and avian species, but not for domestic livestock. This investigation expanded the study of these proteins to include the bovine uterus and examined the levels of CaBP9K and CaBP9K mRNA in the nonpregnant bovine uterus during the estrous cycle. Immunohistochemical studies revealed that CaBP9K was present in all uterine glandular and luminal epithelial cells. In contrast, the closely related calcium binding protein CaBP28K was present in only one to two glandular cells in the samples examined. Neither protein was localized in the myometrium or in the stromal cells of the endometrium. RIA and dot blot hybridization were used to quantify the amount of CaBP9K and CaBP9K mRNA. The levels of both the protein and its mRNA were threefold higher during the luteal phase than during the follicular phase. RIA was also used to determine bovine uterine levels of 17 beta-estradiol and progesterone. Progesterone levels were higher during the luteal phase than during the follicular phase, while 17 beta-estradiol levels were higher during the follicular phase. This investigation represents the first characterization of CaBP9K gene expression in the bovine uterus. It demonstrated that the expression of CaBP9K and CaBP9K mRNA was greatest during the progesterone-dominated luteal phase of the bovine estrous cycle. These results indicated that CaBP9K may be involved in uterine glandular function during the luteal phase.

Immunohistochemical and histochemical identification of proteins and carbohydrates in the equine endometrium: Reaction patterns in the cycling mare

“…The maximal staining intensity of CAL during early-to midinterestrus of mares B and C suggests progesterone-dependent synthesis of protein as reported for other species (Inpanbutr et al 1994, Tatsumi et al 1999. Furthermore, there was a more rapid increase in CAL expression in response to increases in serum progesterone concentrations including a simultaneous increase of both progesterone and CAL at proestrus of mares B and C. The constant low expression of CAL in mare A is probably due to the limited narrow time window for detection of CAL during the estrus cycle of mares.…”

“…Distinct species differences have been reported regarding the regulation of calbindin D9k (CAL) during the estrus cycle. While in bovine (Inpanbutr et al 1994) and murine (Tatsumi et al 1999) endometrium its expression seems to depend on progesterone, a positive influence of estrogen has been shown in the rat endometrium (L´Horset et al 1993). However, there are no reports on its expression in the equine endometrium.…”

Endometrial calbindins are critical for embryo implantation: Evidence fromin vivouse of morpholino antisense oligonucleotides

“…In the bovine uterus, CaBP-d9k expression is higher during the luteal phase than in the follicular phase (24), and, in pigs, endometrial CaBP-d9k mRNA is high just before implantation (days 10-12). However, after attachment (d14), the levels decrease dramatically (25).…”

Effect of vitamin D on testicular CaBP28K expression and serum testosterone in chickens

“…The calcium-binding proteins (CaBPs) CaBP9K and CaBP 28 K are known to be present in target organs of the vitamin D endocrine system. CaBPs have been reported in the reproductive organs of males and females in many species [8,9,[19][20][21][22]. However, in some tissues such as the brain, CaBPs are known to be independent of vitamin D [23].…”