Research over the past decade has indicated that melanocortin peptides are potent inhibitors of inflammation and a promising source of new anti-inflammatory and cytoprotective therapies. The purpose ...of the present paper is to compare protective effects of α-, β-, and γ-melanocyte stimulating hormone on acetaminophen induced liver lesions in male CBA mice. Acetaminophen was applied intragastrically in a dose of 150 mg/kg, and tested substances were applied intraperitoneally 1 hour before acetaminophen. Mice were sacrificed after 24 hours and intensity of liver injury was estimated by measurement of plasma transaminase activity (AST and ALT) and histopathological grading of lesions. It was found that α-, β-, and γ-MSH decrease intensity of lesions by both criteria in a dose-dependent manner.
Optimizirana je priprava većih količina N-1-sulfonilcitozinskih derivata, kondenzacijom sililiranoga citozina i p-toluensulfonil klorida u acetonitrilu. Ovisno o načinu izolacije dobiveni su ...1-(p-toluensulfonil)citozin 2 (80 %) i 1-(p-toluensulfonil)citozin hidroklorid 3 (75 %). NMR eksperimenti pokazuju isključivo nastajanje keto-imino tautomera 3 u DMSO-d6 otopini, dok se 2 pojavljuje u uobičajenome keto-amino obliku. Ispitivani su potencijalni citotoksični učinci N-1-sulfonilcitozinskih derivata 2 i 3 na fibroblastima čovjeka (WI38), stanicama adenokarcinoma gušterače (MIAPaCa2), slabo diferenciranim metastazama adenokarcinoma debelog crijeva (SW-620) i stanicama Burkitt-ovog limfoma (Raji). Rezultati dobiveni MTT-testom pokazuju da ispitivani spojevi djeluju antiproliferativno na različite histološke tipove tumora. U usporedbi s 5-fluorouracilom, N-1-sulfonilcitozinski derivati pokazuju 10 puta jaču inhibiciju rasta izloženih tumorskih stanica. Inhibicijski učinci ispitivanih spojeva na normalne stanice značajno su slabiji u odnosu na protutumorske učinke. Osim antitumorskoga učinka, ispitivani su i hematološki parametri poslije parenteralne primjene ispitivanih tvari.
The structure, complementary structure and cytogenetic/proliferative effects of the Met-enkephalin on human peripheral blood lymphocytes were analyzed. Met-enkephalin, i.e. Peptid-M (LUPEX®), is a ...low molecular weight synthetic pentapeptide that corresponds to thymus Met-enkephalin. Its structure was examined by means of NMR spectroscopy. The influence of Met-enkephalin on in vitro normalization of chromosomally aberrant lymphocytes of patients suffering from different immune-mediated diseases, was analyzed by the sensitive cytogenetic tests for screening and detection of genome damages in human lymphocytes. The tests showed that in vitro stimulation of human lymphocytes with the Met-enkephalin led to dissapearance of different types of chromosome aberrations, reduction in the number of micronuclei, decrease in the frequency of sister chromatid exchange (SCE) and apoptosis as well as a cytostatic effect on mitosis cycles. They have also confirmed normalization of chromosomally aberrant cell findings in patients suffering from different immune-mediated diseases. These results suggest a possible role of Met-enkephalin (Peptid-M) in immunotherapy of different diseases which involve chromosomal aberrations as well as abnormal cell proliferation and offer new approaches to immunotherapy by the use of Peptid-M. Based on the molecular recognition theory and the SCA method, peptide complementary to Peptid-M was designed, synthesized and denoted Peptide-D. Peptide-D is a calpastatin fragment. Predicted ligand-receptor interaction between both peptides is confirmed by the results showing that Peptide-D blocked the Peptid-M induced lymphocyte proliferation in a dosedependent manner.
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