Levels and patterns of acid mucopolysaccharides in bovine coronary arteries without gross lesions.

Abstract

ABSTRACT Levels and patterns of mural acid mucopolysaccharides (AMPS) of left coronary arteries were investigated in 52 cows, 3–10 years old, from New England. In cows with regular sexual cycles the average range of mural total AMPS in coronary arteries varied from 2.1–4.8 mg/g of dry defatted tissue and was in agreement with results obtained in bovine aortas previously reported. Total levels of AMPS were 56.6 % higher in the proliferative than in the progestational period. In pregnant animals the total AMPS levels were similar to those found in oestrus and constant through the gestational period. Mural AMPS levels of the bovine coronary artery were endocrine related. Oestrogenic hormones in particular exhibited a regulatory effect upon the metabolism of mural AMPS. In 14 cases classified as atypical total AMPS values were lower by 30 % or higher by 40 % above the average values found in 29 animals with regular sexual cycles. Increased levels of AMPS may be the non-specific response of the arterial wall to noxious agents (activation of connective tissue – mesenchymal reaction). Lower AMPS values may be explained by endocrine malfunction in these animals. Histochemical observations alone could not reveal an increase or decrease of total mural AMPS. Intensive AMPS staining was observed in cases where the 1 m fraction of the Low sulphated (LS) group was elevated over 20 % of the AMPS pattern. Changes in patterns of mural AMPS in bovine coronary arteries are not a secondary phenomenon, but an early event possibly responsible for the development and progress of bovine coronary artery disease.