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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #93215
Title: DISTRIBUTION AND QUANTIFICATION OF BETA1-, BETA2-, AND BETA3-ADRENERGIC RECEPTOR SUBTYPE TRANSCRIPTS IN PORCINE TISSUES

Author
item MCNEEL, RONALD - BAYLOR COLLEGE OF MED
item Mersmann, Harry

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/7/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: We have investigated the quantity and distribution of certain beta- adrenergic receptors in pig and rat tissues. Beta-adrenergic receptors are entities in fat tissue which are important in the control of fat deposition. Rats and mice are used as models for human obesity. In rat fat tissue, the beta-3 is 10 times as plentiful as the beta-3 in the pig. The pig beta-3 is similar to that in the human. Therefore, it may be that the pig is a better model to study obesity than the rat. Because we now know the quantity and distribution of these receptors in the pig, we can use this information to benefit studies to understand the effects of nutrition on obesity. These results are helpful in furthering our knowledge of the circumstances of obesity, a major, growing health problem in the United States.

Technical Abstract: Distribution and concentration of beta-adrenergic receptor (betaAR) subtype transcripts (beta1AR, beta2AR, and beta3AR) were investigated in porcine and rat tissues. Reverse transcription coupled with the polymerase chain reaction (RT-PCR) indicated the presence of beta1AR and beta2AR transcripts in porcine left ventricle, lung, longissimus muscle, and subcutaneous adipose tissue. RT-PCR indicated beta3AR transcripts were present in porcine subcutaneous adipose tissue, and were suggested in left ventricle and lung, but they were not detected in longissimus muscle. Quantitative ribonuclease protection assays indicated the porcine beta1AR, beta2AR, and beta3AR transcript concentrations. The proportions of porcine betaAR subtypes (beta1AR:beta2AR:beta3AR) were: heart left ventricle=72/28/.25; lung=67/33/.2; liver=45/55/; skeletal muscle=60/39/.7; and subcutaneous adipose=73/20/7. Normalization of data to beta-actin transcript concentration did not change these relationships. In porcine adipose tissue, the concentration of beta1AR transcript was 10-fold greater than that in beta3AR transcript. Rat perigonadal adipose tissue beta1AR and beta3AR transcript concentrations were, respectively, .59 and 1.84 amol/mug total RNA. The rat perigonadal adipose tissue beta3AR transcript concentration was three times that of the beta1AR transcript concentration in the same tissue. The rat perigonadal adipose tissue concentration of beta3AR transcript was 10-fold that of porcine subcutaneous adipose tissue. The most notable difference between the rat and the pig was the predominance of beta3AR transcript in rat adipose tissue while the beta1AR transcript was predominant in pig adipose tissue.