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In this work we studied the alteration of Z-line alpha-actinin in striated skeletal muscle, under conditions of experimental ischemia, by immunohistochemical techniques. alpha-Actinin was extracted and purified from rabbit striated skeletal muscle and used, as an antigen, for the production of antibodies, in sheep. Electrophoresis was performed on PAA sla-gel and the Ag-Ab reaction test on agarose slab-gel (immunodiffusion). Antibodies were used for the indirect immunoperoxidase technique on semithin sections of rabbit striated skeletal muscle, included in in Araldehyde, and observed with phase-contrast microscopy. alpha-Actinin from ischemic muscle because of stenosis of the iliac artery, undergoes a progressive alteration, from the third hour of ischemia, going out of its usual sites. From the fifth to the eighth hour it gradually disappears until it leaves rare and residual points of positive reaction only in correspondence to the Z-lines.

The aim of this research is to show the alterations of alpha-actinin in rabbit myocardium after DMF treatment administered by forced inhalation. Z-lines observed with light and phase-contrast microscopy, appeared to be intact and they were clearly displayed by the indirect PAP-reaction. But if you consider that in normal muscle Z lines do not get coloured by the PAP-reaction without a previous light treatment with trypsin. It may be inferred that, in this case, The DMF has had the same effect as the trypsin, causing alteration to the protein structure. Besides the sarcomeric structure is undoubtedly altered by the DMF, causing alterations, in our opinion, similar to those found in rabbit skeletal muscle, under conditions of acute experimental ischemia.

The various cases of ultrastructural changed in human skeletal muscles in an ischemic state have been examined. From the examination of the material used, it results that in these muscles, certain myelinic figures and autophagic vacuoles are present. These figures are at times linear and in order, whereas in other regions the lamellar components reveal to be disorganized. In many cases, the larger myelinic figure is near the nucleus, almost next to it. Even electron-dense membranes that surround crystalline inclusion placed between the myelinic figures have been observed. The presence of autophagic vacuoles and myelinic figures is important. The cause of this presence is probably due to a different state of degeneration of the different regions in which these vacuoles are or are not present. Both the autophagic vacuoles and the myelinic figures are found associated with the proteolysis of the tissues. Because of these observations, it has been hypothesized that these changes are a consequence of degeneration. Nonetheless, these changes could be caused by both ischemia and atrophy caused by denervation contemporarily, when the above happens in subjects forced to a long-term immobile state, or in an advanced state of gangrene, or during contemporary and associate phlogistic processes with deficient peripheral nervous structures.

When Mooseker and Tilney showed the microvilli system must be ascribed among non-muscle contractile systems, they have proposed a contractile scheme formed by actin, miosin and probably alpha-actinin. The scheme proposed by these AA. consists of actin filaments oriented and running from the border to the base, bound to the border by a plate of dense substance formed by -actinin and, to the base, other perpendicular miosin filaments. In our opinion, Mooseker and Tilney research lacks a demonstration regarding alpha-actinin and that is reason why we have decided to display this protein in the microvilli by immunoperoxidase techniques. Considering our results we can definitively confirm the full validity of the contractile scheme of Mooseker and Tilney.

In this work we studied alpha-actinin and tubulin sites in rabbit fibroblasts in culture. Antibodies anti-alpha-actinin were used for indirect PAP-reaction while antibodies anti-tubulin were used for indirect immunofluorescence method. The observations were carried out by light microscopy, phase-contrast and interference-contrast microscopy, with regard to actinin, and by fluorescence microscopy, with regard to tubulin. During the early mitotic phase, alpha-actinin is localized all over the cell membrane of the fibroblasts, forming a sort strong protective cap, while during diacinesis it forms only rings, localizing below the cell membrane and the philopodia. Thus tubulin forms the bundle fibres during mitotic phases.

In this work we study alpha-actinin sites in rabbit fibroblasts in culture. For this purpose we extracted alpha-actinin from rabbit striated skeletal muscle and produced the relative antibodies in sheep. Electrophoresis was performed, on PAA slab-gel and the immunodiffusion test on agarose slab-gel. Antibodies were used for direct and indirect immunofluorescence techniques by TRIC and FITC. We noticed that in young fibroblasts alpha-actinin is concentrated in perinuclear regions, while in adult fibroblasts it is scattered, more or less evenly in the cytoplasm and above all on the plates which link the cell membrane to the substractum. Both the direct immunofluorescence method with antibodies anti-alpha-actinin, marked by TRITC, and the indirect one with sheep IgG, marked by FITC, gave identical results.