Changes in interstitial cells during development of buffalo testis

Interstitial cells were identified and counted in the testis of Murrah buffalo calves and bulls at the age of 1, 3, 6, 9, 12, 15, 18, 21, 24, 30, 36, 42, 48 and 72 months and older. Six types of cells were identified in the testicular interstitium of 1-month-old calves. These were mesenchymal cells, fetal type Leydig cells, fibroblasts, myoid cells, pericytes and endothelial cells. Adult Leydig cells were visible in 3-month-old calves, but mesenchymal cells were not seen from 18 months onwards. The percentage of mesenchymal cells reached a maximum in 1 month, fetal type Leydig cells in 3 months, adult Leydig cells in 72 months and beyond, fibroblasts in 36 months, myoid cells in 18 months, pericytes in 21 months and endothelial cells after 15 months. Changing percentages of various interstitial cells revealed that myoid cells may have differentiated into fibroblasts and mesenchymal cells, which then differentiated into adult Leydig cells.