Pattern of renal growth and compensatory hypertrophy during development in rats: A mathematical approach

Surgical removal or partial destruction of the kidney is followed by rapid growth, that is, compensatory hypertrophy of the remaining renal tissue. Although similar changes in the kidney mass could be elicited experimentally by other stimuli (such as folic acid, uranyl nitrate, isoproterenol, and so forth) as well, it would be useful to restrict the term of “compensatory hypertrophy” to the growth induced by renal mass reduction. A series of studies appear to indicate that the compensatory growth is evoked and maintained by a specific humoral factor(s) which is present in the plasma as well as in the remaining kidney of the unilaterally nephrectomized animals [1, 3, 11, 12, 13, 16, 17, 22, 23]. Other findings, however, suggest that in the initiation and development of compensatory hypertrophy the lack of inhibitor substance(s), otherwise produced by the normal renal tissue, might also play a role [2, 14, 18, 20]. Several observations on the characteristics of normal and compensatory renal growth seem to sustain the widely accepted view that the initiating and regulatory mechanisms involved in physiologic and stressed renal development are essentially different [6, 15, 19, 21]