Recent advances in our understanding of the fundamental role of bioactive lipids in normal and abnormal physiology was the theme of the XVlth International Spring Sympo- 6-9, 1996 at the George Washington University School sium on Health Sciences held on May of Medicine in Washington, D.C. Over 250 participants shared their latest findings on fundamental mechanisms in lipid metabolism, transport, and signal transduction. Most of the papers presented at the plenary sessions have been collected in this volume, which is divided into seven parts. The focus of Part I is on the new roles that fatty acids and esters play in cellular function. These activities include regulation of gene expression, control of eicosanoid-me- diated responses, and intracellular calcium sequestration. Most biological effects of fatty acids, esters, and phospholipids are transmitted via the interaction of these lipid molecules with specific lipid binding proteins. The chapters in Part II detail the involvement of these in the transport of fatty acids, fatty acyl CoA esters, and phospholipids, and in the proteins modulation of the fatty acid-induced activation of the peroxisome proliferator-activated receptors. The study of arachidonic acid metabolism continues to be the subject of intense interest and research. A number of studies in Part III deal with the substantial differences between the constitutive prostaglandin H synthase isozyme (PGHS-l or COX-I) and the inducible form PGHS-2 (COX-2) regarding compartmentation, control, and expression.

Intercellular communication in multicellular organisms enables cells to respond to environmental changes. Intercellular signal transduction transmitters include hormones, peptide growth factors, neurotransmitters as well as some lipid-soluble mediators. Once signalling molecules are bound to their cell surface receptors, one or more intracellular signals are generated which alter the Qehavior of the target cell. The IXth International Washington Spring Symposium at the George Washington University in Washington, D.C. was organized to assess the current status of the field of signal transduction processes and regulatory mechanisms. The symposium was held on May 8-'.2, 1989 and was attended by more than 1000 scientists from 30 countries. Most of the papers presented at the plenary sessions have been collected in this volume. The first section of this book details the action and regulation of receptors such as ,B-pdr.'nergic receptors and receptors for EGF, insulin, leukotrienes, phosphoinositides and prostaglandins. Section two focuses on the family of guanine nucleotide regulatory proteins (G proteins). These G proteins are known to mediate the coupling of receptor-mediated signals to several intracellular effector systems. Papers are presented describing the intracellular localization of G proteins, the utilization of G protein antibodies, the interaction of G proteins with tubulin and the involvement of G proteins in the regulation of ion channels, adenylate cy~lase and in the activation of neutrophils and T cells. In the third section, several papers describe the second messenger role of phosphoinositides as well as the regulation of phosphoinositide production.

Recent advances in our understanding of the fundamental role of bioactive lipids in normal and abnormal physiology was the theme of the XVlth International Spring Sympo- 6-9, 1996 at the George Washington University School sium on Health Sciences held on May of Medicine in Washington, D.C. Over 250 participants shared their latest findings on fundamental mechanisms in lipid metabolism, transport, and signal transduction. Most of the papers presented at the plenary sessions have been collected in this volume, which is divided into seven parts. The focus of Part I is on the new roles that fatty acids and esters play in cellular function. These activities include regulation of gene expression, control of eicosanoid-me- diated responses, and intracellular calcium sequestration. Most biological effects of fatty acids, esters, and phospholipids are transmitted via the interaction of these lipid molecules with specific lipid binding proteins. The chapters in Part II detail the involvement of these in the transport of fatty acids, fatty acyl CoA esters, and phospholipids, and in the proteins modulation of the fatty acid-induced activation of the peroxisome proliferator-activated receptors. The study of arachidonic acid metabolism continues to be the subject of intense interest and research. A number of studies in Part III deal with the substantial differences between the constitutive prostaglandin H synthase isozyme (PGHS-l or COX-I) and the inducible form PGHS-2 (COX-2) regarding compartmentation, control, and expression.