MLC1 and congenital rubella syndrome: This study demonstrated that SNS could improve CRS-induced diarrhea in rats by inhibiting the CRS-induced up-regulation of DβH and c-fos in the rat brain locus coeruleus, suppressing the increased intestinal and plasma NE content, down-regulating α1-ARs, MLCK, MLC, and p-MLC, and inhibiting the contraction of small arteries in the intestine.