Author
YOKOI, KATSUHIKO - SEITOKU UNIV JAPAN | |
Uthus, Eric | |
Nielsen, Forrest - Frosty |
Submitted to: International Symposium on Metal Ions in Biology and Medicine
Publication Type: Proceedings Publication Acceptance Date: 5/5/2002 Publication Date: 8/1/2002 Citation: Yokoi, K., Uthus, E.O., Nielsen, F.H. 2002. The essential use of nickel affects physiological functions regulated by the cyclic-GMP signal transduction system. Proceedings of the 7th International Symposium on Metal Ions in Biology and Medicine, St. Petersburg, Russia, May 5-9, 2002. Interpretive Summary: Based on studies in which experimental animals were fed low amounts of nickel, it has been suggested that this mineral element is needed for cardiovascular (heart and blood vessels) health. However, unequivocal acceptance of nickel as an essential element awaits the definition of a specific biochemical function in higher animals. Recently, evidence has come forward indicating that nickel might have an essential function in the action or formation of a substance that acts as a signaling agent that regulates various physiological processes in the body; this substance is called cyclic guanosine monophosphate or cGMP. Cyclic CMP is involved in blood pressure control, sperm physiology, and sodium (salt) metabolism. If nickel has an essential role involving cGMP, nickel deficiency would be expected to affect these processes. Thus, two experiments were done with rats that were fed a nickel-deficient or nickel-adequate diet. In one experiment, half of the rats in each nickel treatment were given a substance (L-NAME) in the drinking water; this substance induces high blood pressure through affecting cGMP action. In the other experiment, half the rats in each nickel treatment were fed high dietary salt which increases blood pressure and stresses sodium metabolism, including its elimination via the kidney, through affecting cGMP action. In both experiments, nickel deficiency increased blood pressure, decreased sperm counts and the percentage of motile sperm, and induced kidney damage that impaired its function. The nickel deficiency changes in blood pressure and sperm counts were similar to those induced by L-NAME. Excessive salt worsened the blood pressure and kidney function changes induced by dietary nickel deficiency. The findings support the hypothesis that nickel has an essential function involving cGMP and thus is needed for cardiovascular health. Technical Abstract: Based on studies in which experimental animals were fed low amounts of nickel, it has been suggested that this mineral element is needed for cardiovascular (heart and blood vessels) health. However, unequivocal acceptance of nickel as an essential element awaits the definition of a specific biochemical function in higher animals. Recently, evidence has come forward indicating that nickel might have an essential function in the action or formation of a substance that acts as a signaling agent that regulates various physiological processes in the body; this substance is called cyclic guanosine monophosphate or cGMP. Cyclic GMP is involved in blood pressure control, sperm physiology, and sodium (salt) metabolism. If nickel has an essential role involving cGMP, nickel deficiency would be expected to affect these processes. Thus, two experiments were done with rats that were fed a nickel-deficient or nickel-adequate diet. In one experiment, half of the rats in each nickel treatment were given a substance (L-NAME) in the drinking water; this substance induces high blood pressure through affecting cGMP action. In the other experiment, half the rats in each nickel treatment were fed dietary salt which increases blood pressure and stresses sodium metabolism, including its elimination via the kidney, through affecting cGMP action. In both experiments, nickel deficiency increased blood pressure, decreased sperm counts and the percentage of motile sperm, and induced kidney damage that impaired its function. The nickel deficiency changes in blood pressure and sperm counts were similar to those induced by L-NAME. Excessive salt worsened the blood pressure and kidney function changes induced by dietary nickel deficiency. The findings support the hypothesis that nickel has an essential function involving cGMP and thus is needed for cardiovascular health. |