Compensatory growth (organ)

Compensatory growth is a type of regenerative growth that can take place in a number of human organs after the organs are either damaged, removed, or cease to function.¹ Additionally, increased functional demand can also stimulate this growth in tissues and organs.² The growth can be a result of increased cell size (compensatory hypertrophy) or an increase in cell division (compensatory hyperplasia) or both.³ For instance, if one kidney is surgically removed, the cells of the other kidney divide at an increased rate.¹ Eventually, the remaining kidney can grow until its mass approaches the combined mass of two kidneys.¹ Along with the kidneys, compensatory growth has also been characterized in a number of other tissues and organs including:

• The adrenal glands⁴⁵
• The heart⁵⁶
• Muscles⁵
• The liver⁵⁷
• The lungs⁸
• The pancreas (beta cells and acinar cells)⁷
• The mammary glands⁵
• The spleen (where bone marrow and lymphatic tissue undergo compensatory hypertrophy and assumes the spleen function during spleen injury)⁵
• The testicles⁵
• The thyroid gland⁵⁹
• The turbinates of the nose

A large number of growth factors and hormones are involved with compensatory growth, but the exact mechanism is not fully understood and probably varies between different organs.¹ Nevertheless, angiogenic growth factors which control the growth of blood vessels are particularly important because blood flow significantly determines the maximum growth of an organ.¹

Compensatory growth may also refer to the accelerated growth following a period of slowed growth, particularly as a result of nutrient deprivation.