ABSTRACT
A 140-kDa polypeptide present in the striated muscle of Pecten maximus and Sepia officinalis was purified to homogeneity and its main properties were investigated using biochemical and cytochemical approaches. The protein was found to be similar to chicken gizzard caldesmon. It is a heat-stable protein. It cross-reacts immunologically with anti-(gizzard caldesmon) antibody, binds to calmodulin-Sepharose in a Ca2+-dependent manner, cosediments with F-actin filaments and acts in the absence and presence of tropomyosin as a potent inhibitor of rabbit skeletal actomyosin Mg2+-ATPase. The immunocytochemistry of ultrathin sections revealed, at the light microscopy resolution level, that caldesmon-like protein is present in all types of muscles hitherto examined from invertebrates and vertebrates. However, according to the distribution and the intensity of the fluorescent reaction, we concluded that, under our experimental conditions, caldesmon is not homogeneously distributed and not located in the myofibrillar bands of striated muscles but rather in the sarcoplasmic elements, at the periphery of the fibres.
Subject(s)
Calmodulin-Binding Proteins/isolation & purification , Mollusca/metabolism , Muscles/analysis , Animals , Binding Sites , Ca(2+) Mg(2+)-ATPase/antagonists & inhibitors , Calmodulin-Binding Proteins/pharmacology , Chromatography, Affinity , Dialysis , Drug Stability , Hot Temperature , Immunoblotting , Immunohistochemistry , Muscles/ultrastructureABSTRACT
This work is part of general program of the diagnostic radiation dosage monitoring in the C.H.U. of Brest. The aim of these measurements is to precise the doses delivered to the sensitive organs in infants from one to thirty days of age in the intensive care pediatric Department. We present in this paper the technology used and the results of these controls. We complete this experimental work with a statistical study of the number of radiographies made in the intensive care pediatric Department on 623 children. We insist on the use of leaded protection in the radiodiagnostic practice, as often as it is possible.