RESUMO
The trophoblast is the single most important functional structure of the placenta that mediates the attachment of the blastocyst to the endometrium. Trophoblast has the capability to proliferate in concert with the uterine epithelium to form the only site for nutrient and metabolic exchange between the fetus and dam throughout pregnancy. Trophoblast is made up of a remarkable versatile epithelium showing great capacity for invasion, cell fusion, hormone production, specific nutrient absorption, selective transport, active metabolism, and has the ability to resist maternal immunological attack. These functions are attributed to its inherent ability to synthesize many developmental factors or molecular regulators. While there is an abundance of publications available on the structural, functional, and clinical relevance of the placenta in various mammalian species, a comprehensive review on the comparative aspects of the trophoblast of domestic and companion animals is lacking. Besides, a timely description on the clinical perspective on the functional aspects of the trophoblast in relation to pregnancy diagnosis, placental insufficiency, pregnancy loss, and structural abnormalities of domestic and companion animals is necessary. A brief description on the basic chronology of events in each animal is followed by the applied clinical perspectives of trophoblast. Both the above aspects of trophoblasts of domestic and companion animals including the terminologies are summarized in tables to facilitate discussion.(AU)
Assuntos
Animais , Animais Domésticos/anatomia & histologia , Animais Domésticos/fisiologia , Trofoblastos/fisiologia , Preferência do PacienteRESUMO
The trophoblast is the single most important functional structure of the placenta that mediates the attachment of the blastocyst to the endometrium. Trophoblast has the capability to proliferate in concert with the uterine epithelium to form the only site for nutrient and metabolic exchange between the fetus and dam throughout pregnancy. Trophoblast is made up of a remarkable versatile epithelium showing great capacity for invasion, cell fusion, hormone production, specific nutrient absorption, selective transport, active metabolism, and has the ability to resist maternal immunological attack. These functions are attributed to its inherent ability to synthesize many developmental factors or molecular regulators. While there is an abundance of publications available on the structural, functional, and clinical relevance of the placenta in various mammalian species, a comprehensive review on the comparative aspects of the trophoblast of domestic and companion animals is lacking. Besides, a timely description on the clinical perspective on the functional aspects of the trophoblast in relation to pregnancy diagnosis, placental insufficiency, pregnancy loss, and structural abnormalities of domestic and companion animals is necessary. A brief description on the basic chronology of events in each animal is followed by the applied clinical perspectives of trophoblast. Both the above aspects of trophoblasts of domestic and companion animals including the terminologies are summarized in tables to facilitate discussion.