Neural and endocrine control systems acting on the population kinetics of the intestinal epithelium.

Mechanisms for the control of cell proliferation in those tissues where continuous cell loss is balanced by continuous cell production are still poorly understood. In this paper the factors influencing cell proliferation in the intestinal epithelium are reviewed and it is hypothesised that cell division in the intestinal crypt is regulated by two interacting systems. One of these systems is highly localised, mediated by autonomic nerves and responsive to changes in the rate of cell loss, whereas the other system is generalised throughout the intestine, mediated by hormones and responsive to the nutritional needs of the organism. Experiments to disprove these hypothesis are then suggested.