Cytoprotection by melatonin and growth hormone in early rat myocardial infarction as revealed by Feulgen DNA staining.

Objective: To examine the cytoprotective effect of melatonin or recombinant human growth hormone (hGH) on the early phase of a running myocardial infarction in rats by using the Feulgen staining.

Methods: Rats were subjected to surgical ligature of the left coronary artery or its sham-operation and were studied 1.5 3 h later.

Reduced injury and scar in acute myocardial infarctions treated with human growth hormone.

Repair processes of cells submitted to an injury may exhibit an indirect identifying feature of its activity, based on the amount of connective tissue that could be traced with special stains and morphometry. Hydroxyproline concentration in tissue is also an index with which the presence and amount of repair mechanisms can be assessed. They may be quantitated appropriately in correlation with the end products of collagen, which represent the amount of cicatricial tissue.

[The reduction of the extension and severity of experimental myocardial infarct in pigs with growth hormone. The preservation of the microcirculation].

Administration of hGH during the acute phase of experimental myocardial infarctions in pigs showed several aspects which clearly distinguished the treated group from the control one. In the first case the necrotic segment appeared considerably smaller than in the control group but also exhibit a qualitative different necrotic pattern in the histologic aspect, i.e.