STUDIES ON THE MUSCLE TOXICANT 2,3,5,6,-TETRAMETHYL P-PHENYLENEDIAMINE - EFFECTS ON VARIOUS BIOMARKERS INCLUDING URINARY CREATINE AND TAURINE

The effect of the specific muscle toxicant, 2,3,5,6-tetramethyl p-phen ylenediamine (TMPD), on urinary creatine and taurine, markers of testi cular and liver dysfunction, respectively, has been investigated in ma le Sprague-Dawley rats. Damage to the gastrocnemius and soleus muscles was accompanied by a rise in serum creatine kinase (predominantly the muscle-specific isoenzyme, CK-MM), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Increases in serum alpha-hydroxybut yrate dehydrogenase (HBDH) and total lactate dehydrogenase (LDH) (main ly isoenzymes, LDH(1) and LDH(2)), occurred but only minor damage to t he heart and no rise in CK-MB, (heart muscle isoenzyme) was seen. Dama ge to stage XIV tubules in the testis was evident histologically after the highest dose. This was accompanied by an increase in LDH-C4 testi s-specific isoenzyme and a decrease in serum testosterone. Apart from reduced serum albumin, no other serum parameters indicated liver damag e and there was only slight liver steatosis in some animals at the hig hest dose. Urinary taurine was not significantly raised after any dose of TMPD, but there was a significant increase in urinary creatine aft er the highest dose. It can be concluded that in the presence of discr ete muscle damage, the use of urinary taurine and urinary creatine as markers of liver and testicular dysfunction, respectively, is not conf ounded. However, a variety of different markers should be used in conj unction to fully delineate the tissue damage due to toxic chemicals.