9513873 Reiber Dr. Reiber requests financial support for a one day symposium entitled "Control of Arterial Blood Gases: Ventilatory and Cardiovascular Perspectives", to be held as part of the national meeting of the American Society of Zoologists, December 27-30, 1995 Washington D.C. The symposium will be sponsored by the Division of Comparative Physiology and Biochemistry. The proceedings will be published in the American Zoologist. The control of blood gases is vital and ultimately encompasses such homeostatic processes as acid-base balance and oxygen supply for cellular metabolism. Early studies on the control of blood gases in mammals as well as within comparative physiology, centered around questions of gas exchange and its implications for metabolism. While this line of research proved highly successful by explaining important concepts and identifying controlled parameters, the underlying control mechanisms could not be elucidated. Thus, especially within the last two decades, subsequent studies devoted to neurophysiology and the neurological mechanisms have emerged. The new techniques and questions brought about by the recent neurophysiological approach has unraveled pivotal mechanisms and promises exciting future research. Nevertheless, in spite of the enormous progress, the contemporary dominance of neurophysiology may engender conceptual problems because such studies are becoming increasingly removed from the study of gas exchange, which is the evolutionarily significant factor which is acted upon by natural selection. Consequently, as a main objective of the proposed symposium, Dr. Reiber feels it is pertinent to maintain an integrated view which keep the original questions of gas exchange in perspective but fully utilizes the emerging neurophysiological understanding. In this symposium we will discuss several aspects in which the comparative approach seems most promising. Although not always recognized, studies of invertebrates and non-mammalian vertebrates have contributed enormously to the understanding of gas exchange mechanisms. This will also be the case within the neurophysiological aspect of blood gas regulation, because the receptor systems and mechanisms seem rather conserved and findings in a given group will therefore often provide insight to general relationships. The first half of the proposed symposium focuses on the receptors which control ventilation and the cardiovascular system. Experimental work on both central and peripheral (arterial as well as airway) receptors will be presented. The same overall focus is maintained in the afternoon section, but the main emphasis is placed on the influence of the environment on blood gas regulation. As an interesting objective, he hopes to compare and contrast studies involving acute changes in the environment (such as acute reductions in inhaled Po2) with those of more subtle but longer lasting changes during development. Such comparisons may contribute to the understanding of important questions regarding how receptor "set points" are determined. Thus, the proposed symposium has a very broad scope. The proposed presentations span all major taxonomic groups and touch upon developmental, as well as environmental issues. He therefore expects to capture the interest of a wide audience. ***
