Biosynthesis of Progesterone and 20<i>α</i>-Hydroxypregn-4-en-3-one by the Rat Ovary During the Estrous Cycle and Early Pregnancy

Chatterton, Robert T.; Macdonald, G. J.; Greep, Roy O.

doi:10.1210/endo-83-1-1

Cited by 16 publications

(7 citation statements)

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“…The present histochemical studies agree well with biochemical studies on the secretion of progesterone and 20a-hydroxypregn-4-en-3-one (20a-OH-P) (Eto, Masuda, Suzuki & Hosi, 1962;Telegdy & Endroczi, 1963;Fajer & Barraclough, 1967;Yoshinaga, Grieves & Short, 1967;Hashimoto, Henricks, Anderson & Melampy, 1968;Chatterton, Macdonald & Greep, 1968;Hashi¬ moto & Wiest, 1969;Uchida, Masumikado & Tamotsu, 1969;Roser & Bloch, 1972). The diffuse lipoproteins are presumed to derive from the abundant membranes of smooth reticulum, act as a site for enzymes involved in steroidogenesis and may also serve as a reservoir for the storage of hormone precursors (Flint & Armstrong, 1972;Armstrong & Flint, 1973).…”

Section: Discussionsupporting

confidence: 88%

“…The appearance of increasing numbers of lipid droplets consisting mainly of cholesterol and/or its esters and triglycérides in the granulosa luteal cells during pro-oestrus and oestrus suggests that they begin to function in the storage of hormone precursor. The avail¬ ability of preformed sterol precursors for progestin synthesis is greater in ovaries at pro-oestrus and oestrus than in those at metoestrus or dioestrus (Chatterton et al, 1968). The storage of hormone precursor also correlates well with the falling levels of progestins in the ovarian vein during pro-oestrus and oestrus (Hashimoto et al, 1968), the increased activity of hydrolytic enzymes (Lobel, Rosenbaum & Deane, 1961), the fragmentation and degen¬ eration of the Golgi apparatus (McDonald et al, 1969), and the appearance of 20a-hydroxysteroid dehydrogenase (Balogh, 1964;Pupkin, Bratt, Weisz & Lloyd, 1966;Turolla, Magrini & Gaetani, 1966).…”

Section: Discussionmentioning

confidence: 99%

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Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Guraya¹

1975

Reproduction

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Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Guraya¹

1975

Reproduction

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“…Diestrus I tissue was probably also responsive to hCG, though to a lesser extent. The magnitude of the hCG effect was similar to that reported after in vitro LH stimulation of ovarian slices from cycling rats (14) and of the corpora lutea from PMS-stimulated rats (8). Though further refinement is required, the results suggest that the superfusion technique may offer a new experimental approach for analysis of some aspects of gonadotropic stimulation.…”

Section: Discussionsupporting

confidence: 76%

“…Progestin release continued without apparent decrement for up to 24 hr, indicating extended survival of the tissue during superfusion. The amounts of the steroids in the superfusate were 10-20% of the amounts secreted in vivo (12,13) or synthesized in vitro (14,15), in a comparable period of time. The lower rates during superfusion may be attributable in part to tissue disorganization and the rapid flow of the medium, resulting in loss of extracellular precursor pools.…”

Section: Discussionmentioning

confidence: 84%

“…Similarly, slices of proestrus ovaries gave no greater response to LH stimulation than those of ovaries at other stages of the estrous cycle (14). The absence of the proestrus progestin peak in vitro is of interest in the light of the recent suggestion that the progestins of the proestrus surge have a non-luteal origin, perhaps follicles or interstitial tissue, whereas those secreted during the rest of the cycle are produced by the corpora lutea (22).…”

Section: Discussionmentioning

confidence: 99%

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Progestin Production during Superfusion of Ovaries from Cycling Rats

1973

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Superfusion of partially sliced ovarian tissue from cycling rats using a continuous flow of buffered saline was found to be a useful method for in vitro experimentation. The major metabolite of 3 H-progesterone (P) formed by superfused tissue was 20a-dihydroprogesterone (20aOH-P). Tissue from rats at all stages of the estrous cycle released detectable amounts of both P and 20aOH-P, with the latter steroid predominating. The 20aOH-P/P ratio was highest with proestrus and estrus tissue. The progestins were produced at a constant basal rate during superfusion for at least 24 hr. The greatest amounts of both steroids were released by diestrus tissue. Pulses of human chorionic gonadotropin administered to estrus and diestrus I tissue during superfusion were followed by increases in the amounts of steroids in the superfusate. Smaller and more variable effects were seen with proestrus and diestrus II tissue. The results obtained both before and after gonadotropic stimulation were consistent with production of the progestins primarily by the cells of the corpora lutea. {Endocrinology 92: 265, 1973)

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Epithelial cell proliferation in the mouse vagina during the estrous cycle, pregnancy and lactation: A radioautographic study

Traurig

1971

Anat. Rec.

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A radioautographic study of epithelial cell proliferation in the vaginas of mice during the estrous cycle, pregnancy, lactation, and under certain experimental conditions is reported. Data were expressed as labeled cells per 1000 basal cells counted. The proportion of labeled cells that were basal or nonbasal was determined. The highest rates of proliferation were recorded during the estrous cycle, specifically during late diestrus, proestrus and early estrus. During pregnancy the rates of proliferation increased from metestrous levels beginning on day three and reaching a maximum on day 4 just before implantation, followed by a decrease on days 6 and 8. There was an increase on day 12 followed by a more marked increase on day 19, the last full day of pregnancy. On the first day post partum the rate of proliferation was very low. A small increase followed during early lactation.Data on rates of vaginal epithelial proliferation were used to infer the estrogen secretion pattern during reproduction in the mouse. In addition it was concluded that progesterone augmented the proliferative response of the vaginal epithelium to estrogen, specifically promoting proliferation of nonbasal cells. Experiments using mated, castrated mice and estrogen or progesterone replacement confirmed these conclusions.Data and conclusions are discussed relative to recently reported data on ovarian plasma estrogen and progesterone content in rats during reproduction.

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Biosynthesis of Progesterone and 20α-Hydroxypregn-4-en-3-one by the Rat Ovary During the Estrous Cycle and Early Pregnancy

Cited by 16 publications

References 0 publications

Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Progestin Production during Superfusion of Ovaries from Cycling Rats

Epithelial cell proliferation in the mouse vagina during the estrous cycle, pregnancy and lactation: A radioautographic study

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