4: Growth and bone histology in experimental uremia

Abstract

Material and Methods: Male Sprague-Dawley rats were subjected to subtotal nephrectomy (2 stage procedure with irradiation of rest parenchyma) reducing GFR(CCR) 4 weeks p.o. to 19.8% of shamop, pairfed controls. Serum (creatinine, urea, electrolytes) and urine (electrolytes, protein, cAMP, aminoacids) chemistry, fecal fat and nitrogen, body weight, body length, tibia geometry, tibia histology (v.Kossa stain) and total body fat were measured. Results and conclusions: Longitudinal growth in uremic rats was reduced with respect to ad lib. fed control rats, but identical with respect to pairfed control rats. The reduction of longitudinal growth is entirely accounted for by reduced calorie and protein intake in uremia (U), although rickets (histology) and 20 hyperparathyroidism (histology, urinary cAMP) are present in the U skeleton. In spite of their identical length, weight was less in U rats than in control rats. This difference is not accounted for by difference of intracellular water (measured as difference organ dry weight - organ wet weight) or extracellular water (measured as 82 Br-space). It may point to a disturbance of protein synthesis in U.