Atlas of the vasculature of larval and adult Xenopus

Failure of the cardiovascular system is the leading cause for death in industrialized western countries. The vital role the circulatory system plays under physiological conditions as a transport system for respiratory gases, nutrients, hormones, metabolites, ions, electrolytes, and other substances to and from the body cells as well as its role as a delivery route for a wide range of therapeutical agents in pathological conditions positions this system in the centreline of modern biomedical research. In past years knowledge on the first anlage (vasculogenesis), the growth of new vessels from pre-existing ones (angiogenesis), the factors which regulate these processes (angiogenesis factors) and the wiring of the vessels has increased exponentially. New fascinating insights into the development, structure and function of the cardiovascular system were gained and a tremendous body of knowledge of details of the vasculature from the macroscopic to the submicroscopic level of a wide range of tissues and organs from many different species during various phases of their life history has accumulated. Presently, the development of the cardiovascular system of Xenopus is studied by light microscopy of tissue sections or in-situ hybridization, intravital videomicroscopy, and by confocal light microscopy and our knowledge of the physiology of the developing cardiovascular system is increasing steadily. The gross anatomy of the blood vascular system of larval and adult Xenopus is primarily known from detailed macroscopic and microscopic dissections. In these studies, however, descriptions of the vasculature end when vessels reach the organs parenchyma and too little is known sofar on the intrinsic microvasculature of Xenopus tissues and organs. Scanning electron microscope (SEM) studies using vascular corrosion castings are still rare in Xenopus and concentrate on selected organs only with no systematical analyses of whole organ systems. The microvasculature of most larval and adult animal tissues and organs still awaits a thorough analysis by this powerful technique. The present project will (i) demonstrate the microvascular anatomy of Xenopus laevis throughout tadpole stages 48 through 66 and in adulthood from the macroscopic to the microscopic level, (ii) give a comprehensive insight into the vascular wiring of tissues and organs of this model organism, and (iii) increase knowledge on qualities and quantities of microvascular communication routes between cells, tissues and organs. The goal will be gained by combining the power of scanning electron microscopy of microvascular corrosion castings with light microscopy of stained tissue sections. This combination allows an exact allocation of casted blood vessels to clearly defined tissue layers within individual organs in both larval and adult Xenopus.

Failure of the cardiovascular system is the leading cause for death in industrialized western countries. The vital role the circulatory system plays under physiological conditions as a transport system for respiratory gases, nutrients, hormones, metabolites, ions, electrolytes, and other substances to and from the body cells as well as its role as a delivery route for a wide range of therapeutical agents in pathological conditions positions this system in the centreline of modern biomedical research. In past years knowledge on the first anlage (vasculogenesis), the growth of new vessels from pre-existing ones (angiogenesis), the factors which regulate these processes (angiogenesis factors) and the wiring of the vessels has increased exponentially. New fascinating insights into the development, structure and function of the cardiovascular system were gained and a tremendous body of knowledge of details of the vasculature from the macroscopic to the submicroscopic level of a wide range of tissues and organs from many different species during various phases of their life history has accumulated. Presently, the development of the cardiovascular system of Xenopus is studied by light microscopy of tissue sections or in-situ hybridization, intravital videomicroscopy, and by confocal light microscopy and our knowledge of the physiology of the developing cardiovascular system is increasing steadily. The gross anatomy of the blood vascular system of larval and adult Xenopus is primarily known from detailed macroscopic and microscopic dissections. In these studies, however, descriptions of the vasculature end when vessels reach the organs parenchyma and too little is known sofar on the intrinsic microvasculature of Xenopus tissues and organs. Scanning electron microscope (SEM) studies using vascular corrosion castings are still rare in Xenopus and concentrate on selected organs only with no systematical analyses of whole organ systems. The microvasculature of most larval and adult animal tissues and organs still awaits a thorough analysis by this powerful technique. The present project will (i) demonstrate the microvascular anatomy of Xenopus laevis throughout tadpole stages 48 through 66 and in adulthood from the macroscopic to the microscopic level, (ii) give a comprehensive insight into the vascular wiring of tissues and organs of this model organism, and (iii) increase knowledge on qualities and quantities of microvascular communication routes between cells, tissues and organs. The goal will be gained by combining the power of scanning electron microscopy of microvascular corrosion castings with light microscopy of stained tissue sections. This combination allows an exact allocation of casted blood vessels to clearly defined tissue layers within individual organs in both larval and adult Xenopus.