Morphological Changes in the Kidney of Dogs Chronically Exposed to Exogenous Growth Hormone

Porcine growth hormone was administered subcutaneously to beagle dogs at doses of 0.025,0.1, and 1 IU/kg/d for 14 weeks, markedly elevating serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels. This was accompanied by a significant increase in body weight gain and kidney weights in both male and female dogs. The increase in kidney weight (6 to 54%) was slightly greater than the increase in body weight (6 to 40%). By light microscopy, glomerular deposits, mesangial thickening, and very slight cellular infiltration in glomeruli were seen in mid- and high-dose groups. Based on morphometric evaluation, there was an increase in the renal glomerular area, which was statistically significant (p ≤ 0.05) in the mid- and high-dose males and in the high-dose females. This was associated with a statistically significant (p ≤ 0.05) increase in the number of total glomerular cells in the mid- and high-dose males. By transmission electron microscopy, thickening of the glomerular basal lamina and dif...