Placentary microcirculation in ruminants

• Grant number: 96/06187-8
• Support Opportunities: Research Projects - Thematic Grants
• Start date: January 01, 1997
• End date: December 31, 1998
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Maria Angelica Miglino
• Grantee: Maria Angelica Miglino
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant(s): 99/05561-1 - Vibeke Dantzer | The Royal Veterinary and Agricultural University - Dinamarca, AV.EXT; 99/05562-8 - The structure of blastocerus dichotomus placenta., AR.EXT

Abstract

This investigation is part of or contribution to the "Núcleo de apoio a pesquisa em reprodução animal" and aims at obtaining data on the placental microvascularization of within a study of the umbilical and placental circulation of ruminants. Soon after removal, the vessels of the placenta were injected with Mercox CL-2. The specimens were then immersed in a NaOH 40% solution until complete corrosion, washed, dried and metalized in a SCDB alzers Union Bal-Tec. The preparations were examined under scanning electron microscope DSM 940, ZEISS. The micromorphology and the arrangement of the cotyledonary and chorio-allantoic vessels were studied. Intertwined arterioles, venues and capillaries were identified. The chorio-allantoic membrane of the intercotyledonary area shows particular microvascular architecture, that is, a continuous network of capillaries, the endometrial aspect of which exhibits place with variable depth, irregular surface, arranged in such a way to maintain relations with the uterine mucosa. The capillaries are large and at high magnification the depth and width of the place are seen, being possible to observe irregular areas in their surface. The capillaries of the membrane appear regularly arranged, often following the direction of a major vessel located in the aspect apposite to the endometrial one. In the cotyledonary area, projections of the chronic surface are seen, where its microvascularization appears as trees form by a continuous network of capillaries. Such a network develops around larger vessels, surrounding then spirally, constituting a special arrangement of arterial and venous capillaries separated by a narrow capillary margin. As gestation progresses, this margin widens and forms true place, the surface of which displays more or less deep, irregular areas. (AU)