Cell-specific domains of glial- and muscle-type intermediate filament proteins : Immunoaffinity chromatography and immunoblotting study of GFA protein and desmin

In order to localize the cell specific domains of glial- and muscle-type intermediate filaments, the purified subunits (bovine GFA protein and chicken desmin) were fragmented and the digests passed through immunoaffinity columns or stained by the immunoblotting procedure to determine which fragments reacted with the monospecific polyvalent antisera. The following fragments were found immunoreactive according to these criteria: 30 K (GFA) and 33 K (desmin) N-bromosuccinimide fragments (tryptophan cleavage); 35 K (GFA) and 39 K (desmin) 2-nitro-5-thiocyanobenzoic acid fragments (cysteine cleavage); 18 K (GFA) and 9 K (desmin) cyanogen bromide fragments. Fragmentation of GFA protein was also accomplished using proteolytic digestion with chymotrypsin and trypsin. Two resistant core polypeptides, one about 37 K and stable in the chymotryptic digests and one about 21 K and stable in the tryptic digests bound specifically to the immunoaffinity columns. The 21 K tryptic fragment was found to contain the 18 K cyanogen bromide fragment. The fragmentation patterns support recently published structural domain models for intermediate filament proteins. The immunochemical findings indicate that the immunoreactive regions of GFA protein are located in the aminoterminal region of the middle domain of these models (coil I), while they appear to be situated in the aminoterminal headpiece of the protein in the case of desmin.     

Zymosan activated plasma infusion in sheep: Effects of ethanol administration

Zymosan activated plasma infusion induces pulmonary sequestration of neutrophils and the release of TXA₂ into the pulmonary vascular bed causing profound and transient pulmonary hypertension.Since ethanol (ETOH) inhibits several inflammatory functions of neutrophils, including adherence and aggregation, we examined the ability of anesthetic doses of ETOH to alter the hemodynamic and cellular response to the infusion of zymosan activated plasma (ZAP) in vivo. Twenty five ml of autologous ZAP was intravenously infused into five control and seven (ETOH-treated sheep during mechanical ventillation. In control sheep the mean pulmonary artery pressure (PAP) transiently increased from 14.7±1.4 mm Hg (mean±SEM) to a pead of 38+8 mm Hg by three minutes after beginning the infusion of ZAP. Blood leukocyte concentration transiently decreased 19% below the baseline value due to pulmonary sequestration of polymorphonuclear leukocytes (PMN). Plasma TXB₂ levels measured by radioimmunoassay (RIA) increased from 0.2 to 5.4 ng/ml six minutes after the initiation of ZAP infusion.In five sheep, intravenous infusion of 200 ml of 96% ETOH yielded very high plasma concentrations (882±101 mg%) and completely inhibited both the rise of PAP and the increase of plasma TXB₂ levels after ZAP infusion. However, blood leukocytes transiently decreased 58% below the baseline value. Lower plasma levels of ETOH (200 and 400 mg%) did not prevent either the increase of PAP or the elevation of plasma TXB₂ after ZAP infusion.