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  • 1965-1969  (8)
  • Life and Medical Sciences  (8)
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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 159 (1967), S. 249-253 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Five-day-old mouse blastocysts were transferred into the oviducts of recipients on the second day of pregnancy. S35 methionine was then injected into the recipients and the blastocysts and native 2-celled eggs were recovered six hours later. Radioautographs reveal that the blastocysts incorporate S35 methionine while exposed to the tubal environment to the same degree that they would in the uterus. However, the 2-celled eggs in the same oviducal environment incorporate little or no methionine. It is therefore concluded that the difference in the incorporation of S35 methionine is due to maturational changes in the blastocyst rather than to a deficiency of the labelled amino acid in the tubal lumen.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 157 (1967), S. 163-172 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The effect of exogenous estrogen on tubal transport of ova was determined in the guinea pig, hamster, mouse, rabbit and rat. The animals were given a single injection of estradiol cyclopentylpropionate (ECP) shortly after mating. The dose of ECP required to interrupt pregnancy in 80% or more of the animals was as follows: guinea pig (10 μg); hamster (25 μg); mouse (1 μg); rabbit (50 μg); rat (10 μg). Acceleration of egg transport through the oviduct occurred after the following doses of ECP: guinea pig (50-100 μg); hamster (100 μg); mouse (1 μg and above); rabbit (25 μg); rat (10 μg and above). Hence, the amount of estrogen which accelerates egg transport in the guinea pig and hamster is considerably higher than the dose which interrupts pregnancy.Retentionof ova for longer than the normal period of tubal passage (tube-locking) resulted from the following doses of ECP: guinea pig (250 μg); hamster (250 μg); mouse (1 μg); rabbit (100 μg); rat (no dose). In the species in which ova were tubelocked, the majority of eggs were located at the ampullary-isthmic junction rather than the utero-tubal region of the oviduct.Tube-locking of ova was never observed in the rat; ECP always caused premature entry of eggs into the uterus and eventual expulsion per vaginam. For example, eggs passed through the cervix by 12 hours after the administration of 250 μg ECP at day 1 of pregnancy.
    Additional Material: 13 Tab.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 163 (1969), S. 373-387 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Pregnant mice were hypophysectomized on day 6 and injected subcutaneously with various hormones from days 6 to 9 to establish the minimal requirements for the maintenance of functional corpora lutea. Luteal activity was assessed by the maintenance of pregnancy, weight of embryonic swellings, mean diameter and morphology of corpora lutea, and vaginal histology.Treatment with 2 mg progesterone maintained pregnancy but not corpora lutea in three of five animals. However, the embryonic swellings were significantly (P 〈 0.0005) smaller than those of pregnant control animals. Pregnancy was maintained in all animals when progesterone was combined with 1 μg of estrone. The weights of embryonic swellings and the degree of vaginal mucification in the combined steroid group were similar to those of intact control animals.Treatment with either ovine prolactin, bovine LH, ovine FSH or estrone failed to maintain corpora lutea or pregnancy. Combined injection of prolactin with LH or estrone did not maintain pregnancy or corpora lutea. On the other hand, treatment with 500 μg of prolactin and 200 μg of FSH maintained pregnancy in 12 of 14 animals. All of the aforementioned parameters of luteal activity were comparable to values in intact, control animals.The data indicate that luteal function in the mouse during the early post-implantation period requires a luteotropic complex rather than a single hormone. Prolactin and FSH constitute the minimal luteotropic complex in the pregnant mouse. The luteotropic activity of FSH was not due to its contamination with LH and the effect of FSH was apparently not mediated through estrogen secretion, since pregnancy was not maintained by prolactin and estrone.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 161 (1968), S. 447-457 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The ovary of the newborn hamster is characterized by numerous oogonia which are undergoing mitotic divisions. By day 8, the germ cells have developed into oocytes (dictyate stage). The oocytes and granulosa cells are surrounded by an undeveloped network of fibrous stromal cells until day 14. Between days 14 and 21, the stroma is transformed by hypertrophy and hyperplasia into a primary interstitium consisting of large epithelial cells.The critical period of follicular development is from days 21 to 28, with antral follicles first appearing on day 26. The earliest spontaneous ovulations occur on day 29. This differs from the temporal relationship in the rat and mouse in which antral follicles not only develop several weeks before puberty but can also be induced to ovulate prematurely with exogenous gonadotropins. In contrast, in the hamster the maximal ovulatory response to pregnant mare's serum (PMS) develops rapidly between days 27 to 30. Over this period, induced ovulations increase from an average of 10.5 ova to 55 eggs. The altered responsiveness to PMS does not correlate with any change in the diameter of follicles or number of secondary or tertiary follicles. It is therefore concluded that progressively smaller follicles become competent to respond to exogenous gonadotropin between days 27 and 30.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 163 (1969), S. 359-372 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Various parameters of ovarian activity were determined for the intact or hypophysectomized pregnant mouse, as a baseline to establish the nature of luteotropic hormones in this species.Seventeen per cent of White Swiss mice with a vaginal plug were not pregnant at subsequent stages of gestation. The greatest number of failures occurred between days 12 and 15 of pregnancy, coinciding with the temporary absence of antral follicles and regressive changes in the vaginal epithelium. This suggests that there is a period of transient hormonal imbalance before full placental function is established, which is responsible at this time for the peak in embryonic mortality.Two periods of luteal growth were apparent between days 1 and 4 and 10 to 14 of pregnancy. The first histologic evidence of luteal regression occurred at day 16, correlating with renewed squamous cell proliferation of the vaginal mucosa.There were no significant differences in the number of ova shed on day 1 of pregnancy (11.0 ∓ 0.5 ova) and the subsequent number of embryonic swellings at any stage. Gestation in intact pregnant mice lasted 18 days (n = 2) or 19 days (n = 36). The number of young counted late on day 1 post partum (9.1 ± 0.5) was significantly less than the number of embryonic swellings as a result of maternal cannibalism.Hypophysectomy on day 1 of pregnancy led to rapid histologic degeneration of the corpus luteum. In this feature, the mouse resembled the hamster rather than the rat. Day 10 of pregnancy represented the earliest time at which, at least in some animals the pituitary could be removed and pregnancy continue. Following hypophysectomy from day 11 on, luteal activity, continuation of pregnancy, fetal and placental weight and vaginal histology were comparable to intact, pregnant mice. This is similar to the hypophysectomized rat in the latter half of pregnancy but differs from the situation in the hamster.On the basis of the present findings and results in the following paper, it appears likely that the mouse placenta, in addition to secreting a prolactin-like hormone, also produces other gonadotropins.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 121 (1967), S. 249-258 
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Pregnant hamsters consistently ovulated when injected with 20 IU of human chorionic gonadotropin (HCG). The induced ovulation rate from days 4-8 of pregnancy was comparable to that observed during the estrous cycle; however, starting at day 10, a marked increase occurred, culminating in a peak of 35 ova at day 12. Animals injected with HCG on day 16, the day before delivery, ovulated an average of 14.5 ova, although spontaneous postpartum ovulation does not occur in the hamster. The number of ovulations induced by HCG correlated with the varying number of antral follicles present during different stages of pregnancy.Unilaterally ovariectomized pregnant hamsters did not show a compensatory increase in induced ovulation rate in the remaining ovary.The induction of ovulation on days 4 or 10 of pregnancy did not interfere with embryonic development nor influence the time of parturition. Following parturition, the primary and induced corpora lutea regressed synchronously.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 116 (1965), S. 257-267 
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The hamster ovary has been studied histochemically for various lipids. The granulosa cells of normal follicles contain lipid bodies of various sizes composed mainly of phospholipids. Some lipid bodies also contain triglycerides, cholesterol and its esters. The theca cells contain lipid granules consisting of phospholipids. At the onset of atresia, the granulosa stores lipids abundantly which consist of triglycerides, cholesterol and its esters and a slight amount of phospholipids. The theca of atretic follicles, also stores lipids consisting of phospholipids first, and then in sequence phospholipids and triglycerides and finally phospholipids, triglycerides, cholesterol and its esters. The theca hypertrophies and persists to form the interstitial gland whereas the granulosa cells, with their lipid droplets, regress and disappear. The interstitial gland in the hamster ovary occurs as patches of various sizes and these are derived from the theca of atretic preantral and antral follicles. Most of the lipid droplets of the interstitial gland, are mobilized within the preovulatory ovary. The replenishment of lipid droplets begins on day 1 of the cycle (metestrus). On day 2, the interstitial gland is again filled with lipid droplets which are rich in cholesterol and its esters, triglycerides and phospholipids.In ovaries treated with pregnant mare's serum (PMS) on each of the days of the estrous cycle, numerous large preantral follicles having 4-7 layered granulosa, are stimulated to ovulate. Normally such follicles become atretic, indicating that a lack of sufficient endogenous pituitary gonadotrophins prevents these follicles from maturing. Neutral lipids, especially cholesterol and its esters, could not be demonstrated in the normal granulosa in the PMS-treated ovaries. The follicles, which were atretic at the time of injections, were not affected by exogenous hormones. Human chorionic gonadotrophin (HCG) did not conspicuously affect the growth of follicles. Both PMS and HCG caused mobilization of lipid droplets from the interstitial gland.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 118 (1966), S. 861-872 
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Spayed ginea pigs injected daily for 6 to 10 days with 10, 50, 150 μg of estradiol cyclopentylpropionate (ECP) developed a mucified vaginal epithelium, similar to that observed during pregnancy or following treatment of ovariectomized animals with 5 mg progesterone and 1 μg of ECP.The epithelium did not mucify in spayed guinea pigs given 0.01 to 1.0 μg ECP daily for 10 or more days. Vaginal cornification developed only in animals treated with 1 μg ECP but the reaction was transitory and the keratinized cells were soon replaced by a stratified squamous epithelium.Spayed and adrenalectomized guinea pigs injected daily with 150 μg ECP developed a stratified squamous epithelium rather than a mucified type. However, the vaginal epithelium was mucified in ovariectomized-adrenalectomized guinea pigs receiving 150 μg ECP and corticoids or progesterone. This suggests that after treatment with large doses of estrogen the adrenal of the spayed guinea pig produces progestin-like hormones. These progestins interacting with exogenous estrogen are responsible for vaginal mucification.On the other hand, spayed rats maintained on 1 or 150 μg of ECP showed continuous vaginal cornification, which indicates that there are species differences in the ability of large doses of estrogen to influence the adrenal.
    Type of Medium: Electronic Resource
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