Reproduction in the plains viscacha is characterized by polyovulation of hundreds oocytes, loss implantation and development 1-3 offspring. Our goal was to determine whether placental affected these specializations.Thirteen placentas from early pregnancy near-term were analyzed using histological, immunohistochemical transmission electron microscopy.An inverted, villous yolk sac present. Placentas formed trophospongium, labyrinth subplacenta. A lobulated structure with a hemomonochorial...

Abstract Lagostomus maximus is a South American Hystricognathi rodent whose reproductive behaviour shows characteristics unusual for mammals, such as polyovulation (200–800 oocytes) and high rate of embryo mortality. Thirty‐six mature females captured in the province Buenos Aires showed different physiological stages. Most them presented postpartum oestrus August–September. This characteristic from that reported other geographical areas. The stages considered were: anoestrus, follicular...

Abstract The uterus is an organ with great plasticity due to the morphological and physiological changes it experiences during estrous cycle pregnancy. In mammals, pregnancy requires diverse sex hormones, growth factors cytokines, among others, for promoting uterine remodeling favor implantation, placentation, embryo/fetus survival growth. hystricognathi rodent Lagostomus maximus (plains viscacha) has a high rate of embryonic resorption. cranial middle implants are reabsorbed 25–35 days...

Abstract There is substantial evidence that age-related ovarian failure in rats preceded by abnormal responsiveness of the neuroendocrine axis to estrogen positive feedback. Because IGF-I seems act as a permissive factor for proper GnRH neuronal response feedback and considering hypothalamic content declines middle-aged (M-A) rats, we assessed effectiveness long-term gene therapy mediobasal hypothalamus (MBH) M-A female extend regular cyclicity preserve structure. We used 3 groups rats: 1...

Embryonic death followed by resorption is a conserved process in mammals. Among the polyovular species, Lagostomus maximus (plains viscacha) constitutes model of early and physiological embryonic death, since out total 10-12 implants, 8-10 are resorbed during early/intermediate gestation, surviving only most caudal implantations each uterine horn. This regular reproductive event unique to this but many characteristics gestation L. maximus, when processes begin unknown. The aim present work...

Abstract The main evolutionary milestone in the oviparity–viviparity transition is placentation. placenta an organ with great morphological diversity among eutherians. expression of different glycosidic residues (Gr) near‐term constitutes its glycotype. In this study, Gr was determined by lectin histochemistry early, midterm, and placentas plains viscacha ( Lagostomus maximus ), a caviomorph rodent highest poliovulatory rate embryonic resorption Besides, matrix each exchange trophoblast...

Abstract The oviduct is a very thin organ with tortuous appearance. It divided into three segments: the infundibulum, ampulla and isthmus. Particularly, of viscacha lacks intramural portion described in other species. mucosa shows longitudinal pleats. free edge infundibulum ends as small fimbriae that are variable length do not completely cover ovary. proportion ciliated secretory epithelial cells varied both relation to segments analysed physiological state (anoestrus, follicular phase,...

Abstract The plains viscacha is a hystricognathi rodent with special reproductive characteristics. Despite poly‐ovulation of 800 oocytes, it generates high embryonic mortality since from 10 to 12 implantations only one or two offspring are born. present work analyses the morphological, morphometrical, histochemical and lectinhistochemical characteristics uterus uterine cervix pregnant non‐pregnant viscacha. Anatomically, has horns each continued short devoid glands. structure like that other...

Abstract The general objective of this study focused on the duodenal histological and histochemical analysis fetuses adults plains viscacha ( L agostomus maximus ) from B uenos A ires province rgentina). Histological techniques, procedures for localizing characterizing glycoproteins GP s) lectin techniques identification specific sugar residues were used. structure all age groups here considered was typical mammals. We identified a proliferation phase an epithelial morphogenesis in...

This study reports the histochemistry and distribution of glycoconjugates (GCs) in zona pellucida (ZP) preantral, secondary, tertiary, polyovulatory atretic follicles ovaries from non-pregnant (NPr) pregnant (Pr) females Lagostomus maximus. GCs were studied using histochemical lectin methods. The viscacha ZP was positive to all techniques. In addition, it observed that intensity staining constant different follicular stages between both female groups. revealed for certain lectins (WGA, RCA-I...

ABSTRACT Morphological and histochemical analyses were performed to characterize the histology, ultrastructure, glycosylation pattern of jejunum ileum wild rodent Lagostomus maximus . Enterocytes, goblet cells, Paneth enteroendocrine cells identified in both intestinal epithelia. Two morphological types enterocytes only based on their cytoplasm electron density. Although histological ultrastructural examination showed that epithelia anatomical regions morphologically similar, a certain...

Abstract The ascending colon of most rodent species shows a longitudinal colonic groove that works as retrograde transport pathway for mixture bacteria and mucus toward the cecum. We describe morphology glycosylation pattern Lagostomus maximus to analyze role mucins in this anatomical feature. also studied distribution interstitial cells Cajal (ICC) evaluate their regulatory influence on gut motility. originated near cecocolic junction extended along mesenteric side colon, limited at both...

Abstract The uropygial gland of Southern Caracara is composed two lobes with a conical papilla and 21 tuft feathers. RGM recorded for this species was 0.057%. capsule surrounding the medial septum dense connective tissue has elastic reticular fibres. epithelium adenomers can be divided into different strata: germinative, intermediate, secretory degenerative stratum. three zones; from zone III , lead to secondary chambers that converge primary storage chamber. Histochemical techniques showed...

The presence of a tumor generally changes the mitotic activity normal cell population in mice. In present work, duodenal crypt enterocytes EA21a mammary carcinoma‐bearing mice was determined. results show that there is patent circadian variation and, tumor, proliferation stimulated. Stimulation evident from intermediate as well superficial regions crypt. Some humoral factors produced by transplanted could interfere with regulatory mechanism enterocytes.