Purification of a protein binding quinacrine and histrionicotoxin from membrane fragments rich in cholinergic receptors in Torpedo marmorata]

A protein is purified by differential centrifugation from membrane fragments rich in acetylcholine receptor prepared from Torpedo marmorata electric organ after dissolution by a mixture of non denaturing detergents. After polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate and Coomassie blue staining the purified protein yields a single band of apparent molecular weight 43,000. Spectroscopic experiments carried out in the absence of Ca++ and detergents reveal that the 43 K protein interacts with the fluorescent local anesthetic quinacrine and with the frog toxin histrionicotoxin (apparent KD : 7 X 10(-7) M) but not with carbamylcholine and the alpha toxin from N. nigricollis.     

Reduction of efferent renal nerve activity by propranolol in rabbits]

During intravenous infusion of propranolol (0.3--0.8 mg/kg) in the Rabbit, systolic arterial pressure is decreased (-6.5 +/- 4.2 mmHg) and electrical activity recorded from central end of the renal nerve is reduced significantly (-8.7 +/- 14.-%) with regard to the activity obtained, at the same pressure levels, by hemorrhage (+7.9 +/- 6.4%; p less than 0.25) or by intravenous infusion of the peripheral vasodilator sodium nitroprusside (+14.1 +/- 9.9%; p less than 0.01).     

Cynodontin,the tetrahydroxyanthraquinone ofCurvularia andDrechslera species

Summary The red anthraquinone derivative isolated from several Drechslera and Curvularia species has been identified as cynodontin (1,4,5,8-tetrahydroxy-2-methylanthraquinone), and not as 1,4,5,8-tetrahydroxy-2,6-dimethylanthraquinone as reported earlier. Both pigments showed similar physico-chemical properties. A good distinction could be obtained by gas-liquid chromatography.     

Villus growth and cell replacement in the small intestine of the neonatal pig

Summary Cells produced in the crypts of newborn pig ileum migrate onto villi during development. There is little or no corresponding loss of cells from villus tips during the first week of postnatal life. Villus growth during this period is largely responsible for the slow rate of cellular renewal seen to take place.     

Differentiation antigens in keratinocytes]

By means of indirect immunofluorescence with human sera it has been demonstrated that cytoplasmic components of the basal cell layer showed antigenic differences as compared to the upper cell layers. Moreover there were differences whether the cells were involved in a mucous, a parakeratinized or an orthokeratinized differentiation.     

Molecular aspects of 2 human urinary glycoproteins with histocompatibility antigen (HLA) serological activity]

Two serologically active urinary glycoproteins (HLA-A 9 and HLA-B 12) were isolated from urine provided by a patient suffering from tubular proteinuria. Their N-terminal sequences were automatically determined. The latter were identical with the sequence of another urinary glycoprotein (protein HC). The relationship between protein HC and the serological activity is discussed.     

Immunochemical identification of vitellogenin in the serum of the newtTriturus cristatus

Summary The hematic yolk precursor — vitellogenin — has been identified immunochemically in the serum of estrogenized females of the newtTriturus cristatus by employing an antiserum prepared against yolk proteins.     

Antifertility activity of trimethylphosphate in male rats

Summary The toxic effect of trimethylphosphate on rat testes was investigated after oral dosing with 250 mg/kg for either 5 days/week for 30 days or 6 days/week for 60 days. After these prolonged treatments azoospermia resulted.Acknowledgments. The authors wish to thank Ms M. Michelles, Ms A. Murray and Ms R. Peake for their technical support.