Distribution of mRNA that codes for subtypes of adrenergic receptors in the gastrointestinal tract of dairy cows.
OBJECTIVE
To describe the distribution of mRNA that codes for 9 subtypes of adrenergic receptors in the digestive tract of dairy cows.


METHODS
Fresh full-thickness wall specimens from the abomasum (fundus, corpus, and antrum), ileum, cecum, proximal loop of ascending colon, and 4 locations of the spiral colon collected from 10 healthy cows at slaughter.


METHODS
Concentrations of mRNA that code for 9 subtypes of adrenergic receptors in the bovine gastrointestinal tract (alpha1A, alpha1B, alpha1D, alpha2AD, alpha2B, alpha2C beta1, beta2, and beta3) were measured by use of a quantitative real-time reverse transcription-polymerase chain reaction assay. Results were reported in relation to mRNA expression of the housekeeping gene glyceraldehyde phosphate dehydrogenase (GAPDH).


RESULTS
Mean mRNA contents of adrenergic receptors in the bovine digestive tract were low (range, 0.00006% to 5.04% of GAPDH). Distribution of receptor subtypes was similar in all tissues, with lowest expression of alpha1D receptors, followed by alpha2B, alpha2C, beta3, alpha1B, alpha1A, beta1, and beta2 in the abomasum, whereas alpha2AD and beta2 in the intestines were highest. In comparison with the intestines, relative concentrations of mRNA for receptors beta2 and beta3 were significantly lower in the abomasum.


CONCLUSIONS
Relative concentrations of mRNA that code for adrenergic receptors differed among receptor subtypes and among locations in the bovine gastrointestinal tract. Comparison of these values established in healthy cattle with results for cows with motility disorders, such as abomasal displacement and cecal dilatation, may lead to improved therapeutic or prophylactic approaches for these diseases.
Meylan
Mireille
M
Clinic for Ruminants, Department of Clinical Veterinary Medicine, Vetsuisse Faculty of Berne, Bremgartenstrasse 109a, 3001 Berne, Switzerland.
Georgieva
Teodora M
TM
Reist
Martin
M
Blum
Jürg W
JW
Martig
Johannes
J
Georgiev
Ivan P
IP
Steiner
Adrian
A
D000704:Analysis of Variance; D000818:Animals; D002417:Cattle / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D041981:Gastrointestinal Tract / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D011941:Receptors, Adrenergic / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D018076:DNA, Complementary; D012333:RNA, Messenger; D011941:Receptors, Adrenergic; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases