Skip to main content
ARS Home » Research » Publications at this Location » Publication #63343
Title: NMR STUDY ON MUSCLE METABOLISM AND BODY COMPOSITION OF PIGS WITH DIFFERENT RYANODINE RECEPTOR GENOTYPES

Author
item SCHOLZ, ARMIN - HUMBOLDT UNIVERSITY
item Mitchell, Alva
item WANG, P - HOWARD UNIVERSITY
item SONG, H - HOWARD UNIVERSITY
item YAN, Z - HOWARD UNIVERSITY

Submitted to: Society of Magnetic Resonance
Publication Type: Proceedings
Publication Acceptance Date: 10/11/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary: Pigs that inherit the genes that produces a condition called porcine stress syndrome are known to develop larger muscles and less fat, but also have problems related to energy metabolism in their muscles. The purpose of this study was to use nuclear magnetic resonance techniques (NMR spectroscopy or imaging) to evaluate differences in both energy metabolism in the muscle and body composition of live pigs that were either stress susceptible or non stress susceptible. After only a few minutes exposure to stress by way of an anesthetic, NMR spectroscopy revealed that the susceptible pigs exhibited dramatic changes in muscle energy status, whereas, normal pigs remained unchanged for as long as an hour. Pigs which had inherited only one of the two genes necessary for stress susceptible condition were more like the normal pigs. NMR imaging showed that by the time the pigs weighed only about 20 pounds the stress susceptible pigs already were developing larger muscles than the other two groups. These results contribute to a better understanding of the metabolic processes that result when pigs inherit one or both of the genes responsible for the porcine stress syndrome.

Technical Abstract: In this study, the in vivo 31P NMR spectroscopy is used as a noninvasive method to analyze the metabolic response to a muscle stressor, halothane (HAL). 1H NMR imaging was performed to analyze, if the mutation is connected with a higher muscularity and lower fat deposition already at an early age between 4 and 9 weeks and a body weight between 6 and 15 kg. The 31P NMR spectroscopy study was performed on 69 pigs using a Varian 4.7 T 33 cm horizontal bore magnet. The PSS genotypes (NN, Nn, nn) were identified by the ryanodine receptor gene test. Following the spectroscopy, imaging (MRI) was done on 61 pigs by placing a saddle-shaped surface coil between the shoulder and kidney area. The results confirm, that only the nn genotypes show a dramatic change in their muscle metabolism after about 8 min. HAL exposure. The metabolism of the NN genotypes altered very slowly. Overall, the Nn genotypes had an intermediate response to halothane, though in vivo measurements tended to be more similar to the NN genotypes. The differences among the three genotypes, particularly, in the pH minimum and ATP change are even more obvious by considering the post mortem changes. At about 10 kg body weight, the nn pigs already showed a significant larger MLD volume than the Nn and NN pigs, without significant differences in the overlying fat.