Cardiac Myopathies in Neonatal Lambs: Histological and Histochemical Studies

Abstract

White muscle disease (WMD), a selenium-responsive cardiac myopathy in neonatal lambs has been described from southern Iran. 15 lambs in terminal condition were referred to our lab. All the lambs were observed with the affected hearts. The lambs examined were between the postnatal ages of 1 week and 3 months. Gross changes included chalky-white appearance of entire endocardium of right ventricle and subendocardial plaques in the interventricular septum and left ventricular wall. Histologically the affected myofibrils showed swelling, acidophilia, fragmentation, segmental and patchy myonecrosis, round muscle cell nuclei, loss of sarcoplasm and sarcolemmal collapse. Purkinje fibers were relatively unaffected. Histochemical studies including Von Kossa and other stains indicated marked deposition of calcium salts in the cytoplasm of the damaged myofibrils. Calcium salts appeared as uniform, fine granules in relation to individual fiber striations. It appears that rapid accumulation of calcium into the damaged cells possibly interferes with the mitochondrial activity. As mitochondria bind excessive calcium, their capacity to respire and phosphorylate is depressed thus causing myocardial necrosis. The cardiac myopathy noted in our investigation is probably due to selenium deficiency in the soil of southern Iran. When selenium was given, it resulted in the fast recovery of the affected neonatal lambs. Moreover, no further cases of this disease (WMD) were reported after such treatments.

Field Investigation of Perinatal Mortality in Friesian Cattle Associated with Myocardial Degeneration and Necrosis

“…Nutritional degenerative myopathy (NDM) associated with low uptake of dietary vitamin E and selenium is a well‐recognized disease, causing sudden death (Cawley and Bradley 1978), clinical white muscle disease (Cheema and Gilani 1978) in pre‐weaning calves and young ruminants, and a variety of reproductive conditions (Fenimore et al. 1983).…”

“…The placental lesions and type III hypersensitivity reactions found in several of the fetal conjunctiva in this present study may reflect this. Nutritional degenerative myopathy (NDM) associated with low uptake of dietary vitamin E and selenium is a well-recognized disease, causing sudden death (Cawley and Bradley 1978), clinical white muscle disease (Cheema and Gilani 1978) in pre-weaning calves and young ruminants, and a variety of reproductive conditions (Fenimore et al 1983). In natural disease outbreaks the pathological changes appear to be consistent where sudden deaths have been investigated thoroughly (Bradley et al 1981), and also in experimental studies on calves fed diets deficient in vitamin E and selenium (Kennedy and Rice 1992).…”

Ex vivo diffusion tensor MRI reflects microscopic structural remodeling associated with aging and disease progression in normal and cardiomyopathic Syrian hamsters

“…Each slice was embedded in paraffin and sectioned at 4 μm. The tissue sections were stained with Masson’s trichrome to identify myocardial lesions and von Kossa staining to assess calcium deposition (22). …”

Region-Specific Microstructure in the Neonatal Ventricles of a Porcine Model

“…Current understanding of the young cardiac tissue microstructure is limited to qualitative data, derived from histological analysis of the left ventricle 1,8,31. Emerging three-dimensional techniques are now providing opportunity for quantitative assessment.…”

“…Current understanding of the young cardiac tissue microstructure is limited to qualitative data, derived from histological analysis of the left ventricle. 1 , 8 , 31 Emerging three-dimensional techniques are now providing opportunity for quantitative assessment. Two-photon-excited fluorescence (TPEF) and second harmonic generation (SHG) enable optical sectioning of relatively thick tissue samples.…”