Quantitative mRNA analysis of adrenergic receptor subtypes in the intestines of healthy dairy cows and dairy cows with cecal dilatation-dislocation.
OBJECTIVE
To investigate the distribution of mRNA coding for 9 adrenoceptor subtypes in the intestines of healthy dairy cows and cows with cecal dilatationdislocation (CDD).


METHODS
Full-thickness specimens of the intestinal wall were obtained from the ileum, cecum, proximal loop of the ascending colon (PLAC), and external loop of the spiral colon (ELSC) of 15 cows with CDD (group 1) and 15 healthy (control) cows (group 2, specimens collected during laparotomy; group 3, specimens collected after slaughter).


METHODS
Concentrations of mRNA for 9 adrenoceptor subtypes (alpha(1A), alpha(1B), alpha(1D), alpha(2AD), alpha(2B), alpha(2C), beta(1), beta(2), and beta(3)) were measured by quantitative real-time reverse transcriptase-PCR assay. Results were expressed relative to mRNA expression of a housekeeping gene.


RESULTS
Expression of mRNA for alpha(1B)-, alpha(2AD)-, alpha(2B)-, beta(1)-, and beta(2)-adrenoceptors was significantly lower in cows with CDD than in control cows. In the ileum, these receptors all had lower mRNA expression in cows with CDD than in control cows. The same effect was detected in the ELSC for mRNA for alpha(2AD)-, alpha(2B)-, beta(1)-, and beta(2)-adrenoceptors, and in the cecum and PLAC for alpha(2B)- and beta(2)-adrenoceptors. Groups did not differ significantly for alpha(1A)-adrenoceptors. The mRNA expression for alpha(1D)-, alpha(2C)-, and beta(3)-adrenoceptors was extremely low in all groups.


CONCLUSIONS
Differences in expression of mRNA coding for adrenoceptors, most pronounced in the ileum and spiral colon, between cows with CDD and control cows support the hypothesis of an implication of adrenergic mechanisms in the pathogenesis of CDD in dairy cows.
Kobel
Barbara
B
Clinic for Ruminants, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Berne, Bremgartenstrasse 109a, 3001 Berne, Switzerland.
Engel
Ladina
L
Ontsouka
Edgar C
EC
Graber
Hans U
HU
Blum
Jürg W
JW
Steiner
Adrian
A
Meylan
Mireille
M
D000818:Animals; D002417:Cattle / Q000378:metabolism*; D002418:Cattle Diseases / Q000235:genetics* / Q000473:pathology*; D002429:Cecal Diseases / Q000235:genetics / Q000473:pathology / Q000662:veterinary*; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000235:genetics; D006262:Health; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000473:pathology*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D011941:Receptors, Adrenergic / Q000145:classification / Q000235:genetics*
D012333:RNA, Messenger; D011941:Receptors, Adrenergic