proestrus


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Related to proestrus: metestrus, estrous

proestrus

[prō′es·trəs]
(physiology)
The beginning of the follicular phase of estrus.
References in periodicals archive ?
Because LIF mRNAs increased significantly at late diestrus and proestrus phases in this study and the expression of Lif and Lifr is induced by the steroid hormones estrogen and progesterone in rodent endometrium [19, 20], we determined whether [E.sub.2] and [P.sub.4] affected the expression of LIF and LIFR mRNAs in endometrial explant cultures from immature gilts, that were not exposed to cyclical ovarian hormones.
Cytological examination revealed that both control and vehicle mice had normal estrous cyclicity and showed different stages of the cycle containing proestrus (round, nucleated epithelial cells), estrus (cornified squamous epithelial cells), metestrus (cornified squamous epithelial cells and predominance of leukocytes), and diestrus (predominance of leukocytes) (Table 1).
It is well described that the oestrous cycle of rats lasts four or five days and consists of proestrus, oestrus, metoestrus, and dioestrus, and includes various alterations in the concentrations of gonadal steroids and gonadotropins.14-17 Briefly, in the proestrus phase, the oestradiol level rises and ovarian follicles grow fast.
The estrous cycle consists of four phases called proestrus, estrus, metestrus and diestrus; each distinguished by the type and amount of vaginal epithelial cells, and the presence or absence of leukocytes in the vagina (Yener et al., 2007; Byers et al., 2012.).
Moreover, Giemsa staining was used to ensure that all animals were killed at the proestrus stage of the estrus phase.
At 8-week treatment and 4-week recovery, the fertility of each male rat was assessed by naturally mating with two proestrus virgin females.
By the way, the relevance of progesterone, alone or together with estrogens, as the main factors regulating hippocampal ability to store and retrieve memory is supported by the increased risk to develop Alzheimer's disease in postmenopausal women [62, 63] and by the observation that the antiprogestin RU486 administration on proestrus blocks the natural decline of synapse density related to cycle [64].
Females of proestrus and estrus periods were placed with fertile males at the ratio 2:1.
Despite persistent expression of the signal throughout all stages of the estrous cycle, mRNA levels of ghrelin change in a cyclic fashion, with lowest expression occurring in the proestrus phase, and maximum values in the diestrous phase (11).