Document Detail

The carnivore pregnancy: the development of the embryo and fetal membranes.
MedLine Citation:
PMID:  16563485     Owner:  NLM     Status:  MEDLINE    
The aim of this research was to compare the morphological aspects during the development of pregnancy in dogs and cats, distinguishing features of the fetal membranes, such as yolk sac evolution and differentiation of hemangioblasts, and the degree of elaboration of the amnion and allantois. Canine and feline placentae from 20, 24, 35, 45 and 55 d of pregnancy were perfusion-fixed for histological investigation and vascular corrosion casts were produced. The casts were prepared for scanning electron microscopy (SEM) and the embryo and fetal membrane development was analyzed. The growth patterns of the conceptuses were compared with the organization of the placentation process, and changes of the morphology during pregnancy were recorded. In feline placentae, an incomplete zonary shape was present in 62.5% out of 60 studied cases. This was located distal to the insertion of the umbilical cord. In the lamellar zone, the interhemal membrane or placental barrier resembled endotheliochorial conditions, and the maternal-fetal microvascular blood flow interrelationship was of simple crosscurrent type. Dogs have a zonary placenta, completely surrounding the fetus, and complex lamellar organization of maternal and fetal tissues. At the border, two marginal hematomes with green colouration delimited the central placental girdle. The yolk sac consisted of one large sacculation with an inverted "T" shape and an enormous number of blood vessels; it had hemangioblast cells in contact with the epithelium. The amnion was avascular in early stages, but became vascularized by blood vessels of the internal allantoic membrane in later stages of pregnancy by intrinsic relation.
Maria Angelica Miglino; Carlos Eduardo Ambrósio; Daniele dos Santos Martins; Cristiane Valverde Wenceslau; Christiane Pfarrer; Rudolf Leiser
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2006-03-23
Journal Detail:
Title:  Theriogenology     Volume:  66     ISSN:  0093-691X     ISO Abbreviation:  Theriogenology     Publication Date:  2006 Oct 
Date Detail:
Created Date:  2006-09-18     Completed Date:  2006-11-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0421510     Medline TA:  Theriogenology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1699-702     Citation Subset:  IM    
Faculdade de Medicina Veterinária e Zootecnia, University of São Paulo, Brazil.
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MeSH Terms
Cats / anatomy & histology,  embryology*,  physiology
Dogs / anatomy & histology,  embryology*,  physiology
Embryonic Development / physiology*
Extraembryonic Membranes / anatomy & histology,  growth & development*
Histocytochemistry / veterinary
Microscopy, Electron, Scanning / veterinary
Placenta / anatomy & histology,  growth & development*
Pregnancy, Animal / physiology*

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