Altered expression of sodium pump isoforms in the inflamed intestine of Trichinella spiralis-infected rats
Khan, I.; Collins, S.M.
American Journal of Physiology 264(6 Pt 1): G1160-G1168
1993
ISSN/ISBN: 0002-9513 PMID: 7687413 Document Number: 407057
We used polymerase chain reaction (PCR) and Northern analysis to examine the effect of Trichinella spiralis infection on mRNA expression of sodium pump isoforms in rat intestine. 28S RNA was coamplified as an internal standard, and the abundance of the isoformic mRNA was expressed relative to 28S RNA. As assessed by PCR and Northern analysis, the a1- and b1-subunits were expressed in the jejunum and ileum of noninfected control rats. However, in the jejunum the levels were suppressed after 24 h of infection. The suppression became maximal by day 6 and was reversed to normal by day 23 postinfection (PI). In contrast, no suppression was observed in the noninflamed ileum of infected rats. Further analysis revealed that a1-mRNA was suppressed in jejunal mucosa by 89% and in longitudinal muscle-myenteric plexus by 62% but was not suppressed in circular muscle. Western blot analysis revealed a 61% decrease in the a1-subunit protein in the mucosa and a 62% decrease in longitudinal muscle, whereas there was no change in the a1 protein in circular muscle on day 6 PI. In contrast, marked (89%) suppression of b1-mRNA was observed only in the mucosa; there was no change in either circular or longitudinal muscle on day 6 PI. These results indicate that T. spiralis infection in the rat is accompanied by a significant decrease in the a1-subunit of the sodium pump in longitudinal muscle. This reduction could result from altered regulation involving pretranslational changes. The pump suppression was observed only in the jejunum and not in ileum and is likely to be secondary to the inflammatory response to the infection. Reprinted by permission of the publisher.