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L L Salcedo

Publications and source records attributed to L L Salcedo.

10 recordsLinked to original sources

Elastin biosynthesis and cross-link formation in rabbit aortic smooth muscle cell cultures.

Rabbit aortic smooth muscle cells in culture produce insoluble elastin which can be purified by treatment with hot alkali. These cells, when maintained in the same flask for long periods of time, continue to accumulate elastin. Both desmosine and isodesmosine, cross-links unique to insoluble elastin, have also been found to increase with time in culture. The results from pulse-chase studies with radiolabeled proline and lysine confirm these observations. All the data indicate that the appearance of the desmosines in the elastin in these cell cultures is a relatively slow process, while the lysine-derived aldehydes appear quite rapidly.

Animals↗

Formation of elastic fibers and elastin in rabbit aortic smooth muscle cell cultures.

Cultured rabbit aortic smooth muscle cells produce elastic fibers and elastin in their extracellular matrix. Morphological analyses of elastic fibers indicate that they consist of two distinct components which play a major role in elastic early fiber formation namely, the amorphous component and the "microfibrillar" component. During elastogenesis, the early fiber consists of small bundles of filaments. Later, clearly distinguishable small conglomerates of amorphous material are found distributed among the bundles of filaments. The mature elastic fibers have large conglomerates of amorphous material with the filaments present within the interstices. Long term cultures of these cells in the second passage continue to accumulate elastin. The crosslinking amino acid isomers desmosine and isodesmosine, which are unique to insoluble elastin, increase with time in culture. Twenty-four hour pulses with 14C-proline followed by measurements of 14C-hydroxyproline in the collagenase resistant protein of the cell layer show that the synthesis of insoluble elastin is constant up to the 14 week period studied from the time the amorphous material becomes evident ultrastructurally.

Amino Acids↗

The synthesis of connective tissue protein in smooth muscle cells.

The synthesis of elastin by smooth muscle cells was clearly demonstrated by amino acid analyses and the presence of lysine-derived crosslinks. The values obtained were compatible with those found in amorphous elastin isolated from rabbit aortic tissue. Collagen synthesis by these same cells was monitored by the appearance of [14C] hydroxyproline when the cells were grown in the presence of [14C] proline. When the cells were pulsed with [14C] lysine, one could detect [14C] hydroxylysine and [14C] glucosylgalactosylhydroxylysine. Further evidence for the synthesis of elastin and collagen was the finding of radiolabelled epsilon-hydroxynorleucine and the reduced aldol condensate of two residues of allysine after reduction of [14C] lysine pulsed cells with NaBH4.

Animals↗