Histological and histochemical observations on the armadillo uterus during the delayed and post‐implantation periods

Enders, Allen C.; Buchanan, G. D.; Talmage, Roy V.

doi:10.1002/ar.1091300403

Cited by 14 publications

(12 citation statements)

References 4 publications

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“…Accumulation of glycogen granules was observed in the glandular epithelium of several animals in the 3rd week following spaying. The cellular hypertrophy so characteristic of the endometrium of implanta¬ tion [Enders, Buchanan & Talmage, 1958] was not observed prior to day 22.…”

Section: Resultsmentioning

confidence: 88%

Some Effects of Ovariectomy and Injection of Ovarian Hormones in the Armadillo

Enders¹,

Buchanan²

1959

Journal of Endocrinology

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The uteri of armadillos, spayed before they had ovulated, declined in weight. Administration of oestradiol to such animals results in a gain in uterine weight due primarily to an increase in thickness of the myometrium.In animals bilaterally ovariectomized subsequent to ovulation, implantation occurred regularly 22-24 days postoperatively, with little loss of blastocysts.The administration of progesterone to animals from which the ovary containing the corpus luteum has been removed is compatible with maintenance of the blastocyst. In one instance an unimplanted blastocyst was recovered on day 31 after operation.The enigma of implantation following bilateral ovariectomy in this species remains unexplained.

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Section: Resultsmentioning

confidence: 88%

Some Effects of Ovariectomy and Injection of Ovarian Hormones in the Armadillo

Enders¹,

Buchanan²

1959

Journal of Endocrinology

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“…Ectopic pregnancies occur frequently in man and most often the embryo is found to have implanted in the Fallopian tube [1], Although abdominal pregnancies have been reported in a variety of mammals [2][3][4][5][6][7][8], tubal pregnancies have rarely been described. This scarcity of tubal pregnancies is surprising in view of the fact that under experimental con ditions embryos from mice, rats and guinea pigs readily implant when transferred to a variety of extrauterine sites regardless of the hormonal status of the recipient.…”

Section: Introductionmentioning

confidence: 99%

The Fate of Trophoblast Retained within the Oviduct in the Mouse

Tutton¹,

Carr²

1984

Gynecol Obstet Invest

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Pre-implantation blastocysts or trophoblast, obtained from ectoplacental cones, were transferred to the right oviducts of both pregnant and nonpregnant mice. Blastocysts which remained within the oviductal lumen did not show evidence of further differentiation into trophoblast although they readily implanted on various extratubal sites. Similarly, trophoblast from ectoplacental cones failed to show invasive properties when restricted to the lumen. In 3 cases where trophoblast giant cells were found within the tubal lumen, entry appeared to have been contingent on an existing breach in the epithelium. Invasive action on tubal epithelium by trophoblast was not seen.

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“…During the delay period, the single blastocyst lies in a small depression in the endometrium at the fundic tip of the uterus (Patterson, 1913). Implantation occurs at this site, the penetrating trophoblast rapidly gaining access to the large blood sinusoids which, in this region, are quite close to the luminal epithelium (Enders, Buchanan &Talmage, 1958).Although implantation has not been found to occur elsewhere within the endometrium, there has been no suggestion that this very small region was physiologically different from other portions of the fundic endometrium and one could presume that implantation in this location was simply the result of the anatomic positioning of the blastocyst. Information on this point could be pro¬ vided by following the fate of two blastocysts in a single uterus, but no such case appears to have been reported.…”

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confidence: 99%

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confidence: 99%

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The Presence of Two Conceptuses in the Uterus of a Nine-Banded Armadillo

Gd¹

1967

Reproduction

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Summary. A nine-banded armadillo was found to contain an early implantation site in the fundic tip of the uterus and an extraordinarily large free blastocyst in the central portion of the uterine cavity. This finding suggests that only the small portion of the endometrium in the fundic tip of the uterine cavity is competent to accept the blastocyst.The nine-banded armadillo (Dasypus novemcinctus) is monovular, exhibits specific polyembryony and has a period of delayed implantation, which in the United States is about \\ months long. During the delay period, the single blastocyst lies in a small depression in the endometrium at the fundic tip of the uterus (Patterson, 1913). Implantation occurs at this site, the penetrating trophoblast rapidly gaining access to the large blood sinusoids which, in this region, are quite close to the luminal epithelium (Enders, Buchanan &Talmage, 1958).Although implantation has not been found to occur elsewhere within the endometrium, there has been no suggestion that this very small region was physiologically different from other portions of the fundic endometrium and one could presume that implantation in this location was simply the result of the anatomic positioning of the blastocyst. Information on this point could be pro¬ vided by following the fate of two blastocysts in a single uterus, but no such case appears to have been reported. In fact, in an extensive investigation of the re¬ productive cycle of the nine-banded armadillo begun at Rice University some years ago, several hundred female reproductive tracts were examined, and only seven cases of double ovulations were found (Enders, 1966). Three of these were non-pregnant, three had single conceptuses and one had a morula in each oviduct. Recently, the writer examined an armadillo uterus which contained two conceptuses, and is described below.

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Histological and histochemical observations on the armadillo uterus during the delayed and post‐implantation periods

Cited by 14 publications

References 4 publications

Some Effects of Ovariectomy and Injection of Ovarian Hormones in the Armadillo

Some Effects of Ovariectomy and Injection of Ovarian Hormones in the Armadillo

The Fate of Trophoblast Retained within the Oviduct in the Mouse

The Presence of Two Conceptuses in the Uterus of a Nine-Banded Armadillo

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