Effect of Short-Term Ethanol Feeding on Rat Testes as Assessed by 31P NMR Spectroscopy, 1H NMR Imaging, and Biochemical Methods.

31P Nuclear magnetic resonance (NMR) spectroscopy and 1H NMR imaging were used to examine the effect of short-term ethanol feeding on the rat testis. Weanling rats were pair-fed for 10 weeks either on ethanol containing liquid diet (36% ethanol of total calories) or a diet in which dextrimaltose was isocalorically substituted for the ethanol of the alcohol-containing diet. In vivo 31P NMR of the testes was used to determine the intratesticular pH and the relative concentrations of various phosphorus-containing metabolites. The integrity of the blood-testes barrier was evaluated using 1H NMR imaging following a gadolinium diethylene tetramine pentacetic acid derlvative (Gd-DTPA) administration as a vascular contrast agent. After the completion of NMR studies, the testis and the liver were freezeclamped to allow for the assay of their adenosine-5′-triphosphate (ATP) contents. Serum was assayed for its content of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alcohol and testosterone. Ethanol feeding resulted in the following: (a) a reduction in the body weight (p < 0.05), (b) a reduction in the testicular phosphodiesters (PDE) PDE/ATP ratio ( p < 0.05), (c) an increased change in the testis image intensity difference between pre- and post-iv Gd-DTPA images, (c) a reduction in the testicular and hepatic content of ATP, and (d) increased serum levels of AST and ALT. Therefore, using NMR Spectroscopy and imaging, it has been possible to demonstrate that the metabolic alterations which occur in the testes in response to short-term ethanol feeding within the present experimental protocol precede the reduction in the serum testosterone level produced by ethanol and is associated with an early disruption of the blood testes barrier. [ABSTRACT FROM AUTHOR]