Bridging the gap between physiology and molecular biology: new approaches to perpetual questions

Living organisms are the result of precise and complex associations of regulatory systems in which active biomolecules interact with one another and respond to the challenges of growth and development, alterations in the environment, and disease. Understanding of body homeostasis may be accomplished at various levels of scientific endeavor. Physiological research has brought about an enormous understanding of the fundamental principles that sustain life in health and disease. The field of molecular biology has provided new tools and strategies with which to examine physiological processes as viewed from the level of fundamental biomolecules. The integration of both fields as "molecular physiology" has provided the opportunity for another level of scientific understanding and the opening of new avenues of research. Renin is one such molecule that participates in the control of several diverse physiological responses including changes in blood pressure, fluid and electrolyte homeostasis, renal function, and perhaps some elements of growth and differentiation. Because of the authors' bias, this review article will use renin to introduce many of the techniques of molecular biology and illustrate the areas of ongoing and potential interdependent activities resulting in the emerging field of molecular physiology.