Ovarian Estrogen Secretion During the Estrous Cycle and Under the Influence of Exogenous Conadotropins in Rats

Ovarian Secretion of Progesterone and 20α-Hydroxypregn-4-en-3-one during Rat Estrous Cycle in Chronological Relation to Pituitary Release of Luteinizing Hormone

“…This corresponds with the results reported by Eto et al(1962) and Hashimoto et al(1968). Figure 6 illustrates a chronologic relation of the pattern of preovulatory increase of progesterone secretion to the patterns of estrogen secretion (Hori et al, 1968) and plasma LH concentration (Kobayashi et al, 1968) and to the timing of ovulation (Kobayashi et al, 1968) in the 4-day cyclic rats of the same strain bred under the same lighting schedule (12 hrs. light, 8 a.m. to 8 p.m.), the outline of which was reported in a proceeding form (Miyake, 1968).…”

“…Chronologic relation of preovulatory secretion of progesterone to estrogen secretion, LH release and ovulation (Hori et al, 1968;Kobayashi et al, 1968). ing blood is undetectable (Kobayashi et al, 1968), and further, the same grade of increased secretion rates at this time is manifested even in the rats hypophysectomized on the morning of the day of early diestrus or on the afternoon of the day of estrus. This concept is supported by the in vitro experiments of Chatterton et al (1968), who have demonstrated that the rat ovarian tissue at any stage of the cycle is able to synthesize a considerable amount of progesterone and 20a-OH-P in the medium without LH and the incorporation of acetate-1-14 C into progesterone and 20a-OH-P is not affected by LH, whereas the incorporation of acetate into both progestins is markedly higher during the luteal phase.…”

Oestradiol-17β and prolactin levels in rat peripheral plasma

“…The reliability of each method has been examined and the basal levels of each hormone have been measured at various stages during the oestrous cycle, in ovariectomized animals and in males. Although the fluctuations in plasma oestradiol-17/3 (Hori, Ide and Miyake, 1968;Yoshinaga, Hawkins and Stocker, 1969;Brown-Grant, Exley and Naftolin, 1970; Shaikh, 1971;Dupon and Kim, 1973), and plasma prolactin (Kwa and Verhofstad 1967; Niswender et al, 1968;Gay, Midgeley and Niswender, 1970;Amenomori, Chen and Meites, 1970;Neill and Reichert, 1971;Neill, 1972) during the oestrous cycle have been reported previously, the results of simultaneous measurements of both hormones in individual rats have not to our knowledge been published. …”

On Circulating Sex Steroids During the Estrous Cycle and the Early Pseudopregnancy in the Rat with Special Reference to its Luteal Activation

“…Measurements of radioactivity Counting and data processing were carried out as previously reported (Horikoshi and Wiest, 1971 assessed directly by the estrogen assays in the ovarian venous blood (Hori et al, 1968 ;Yoshinaga et al, 1969 ;Shaikh, 1971) or in the peripheral blood (Brown-Grant et al, 1970), though these data have been mainly compiled only in the stages of diestrus and proestrus . As seen in Figure 1-a, our data clearly indicate that the circulating E-2 shows only one rise spreading from 1600 of Day D to 1400 of Day P throughout the estrous cycle.…”