To assess the role of metabolic shifts in pathogenesis of excretory renal dysfunction arising in chronic glomerulonephritis (CGN), two groups of patients were considered. Fourteen patients of group 1 had CGN in a preazotemia stage, thirteen patients of group 2 died of CGN-induced uremia. Cortical nephrobiopsies obtained intravitally (group 1) and renal tissue specimens obtained at autopsies during postmortal hours 0-2 (group 2) were investigated.
View Article and Find Full Text PDF[D-Arg2,Leu5]enkephalin and its analogues, shortened from the C-terminus, were studied in a rat brain membrane fraction with the aid of radioreceptor analysis. The interaction between these compounds and the peripheral opiate receptors of isolated organs (guinea pig ileum and mouse vas deferens) was also investigated. The ethyl ester of the [D-Arg2]tripeptide retains approximately 10% of the mu-receptor activity of leucine-enkephalin.
View Article and Find Full Text PDFThe sterically acceptable structures of cyclo(2 delta----5)[D-Orn2, Pro5]- and cyclo(2 delta----5)[D-Orn2, Leu5]enkephalin (CE1 and CE2) consistent with NMR data including coupling constants, temperature dependencies of chemical shifts for amide protons and NOE values have been found by use of energy calculations in terms of rigid valence geometry and refined by the MM2 procedure. It has been shown that the major trans-isomer (with respect to Phe4-Pro5 bond) of CE1 in solution corresponds only to the FD*F*AA type of peptide backbone, and the minor cis-isomer of CE1 corresponds only to the FE*D*DF type. The less conformationally rigid CE2 analogue apparently exists in solution in the dynamic conformational equilibrium with preference of FD*C*AA type of the backbone structure.
View Article and Find Full Text PDF[D-Arg2,Leu5]Enkephalin and two series of its N-terminal short-chain analogues with a free and modified C-terminal carboxylic group, viz. amides and ethyl esters of tri- and tetrapeptides, were synthesized in solution and by solid-phase method. Their analgesic activity, assayed by the "tail pinch" method following intracisternal and intravenous administration to mice, was compared with activity of enkephalins and morphine.
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