Cadmium-113 FT NMR-spectra of rabbit liver metallothioneins

Summary Cadmium-113 FT NMR-spectra of rabbit liver metallothionein-I and-II gave 6 and 7 NMR-signals, respectively, at between 610 and 670 ppm downfield from aqueous Cd(ClO₄)₂ solution (0.1 M).We thank Mr M. Imanari (JEOL) for the NMR-data and Dr K. Kubota (NIES) for encouragement.     

Modification of the action of pentagastrin on acid secretion by botulinum toxin

Summary I.v. botulinum toxin after 60–90 min abolished the dose-response relationship between pentagastrin and gastric acid secretion in anesthetized rats and guinea-pigs. The toxin reduced but did not abolish the acid stimulatory effect of histamine. As expected, the acid response to vagal stimulation was abolished and that to methacholine in rats was unaltered by the toxin.Acknowledgment. We are grateful to the generosity of Dr Edward J. Schantz, Food Research Institute, University of Wisconsin, for the botulinum toxin used. — This research was supported by NIH grant 1 RO1 AM 17125, The Secretion of Pepsin.     

Purification and structural characterisation of human HLA-linked B-cell antigens.

The human B cell-specific alloantigen which is closely linked genetically to HLA contains two non-covalently associated, sialogycoprotein subunits of molecular weight (MW) 29,000 (p29), and 34,000 (p34). Although p29 and p34 have different amino-terminal sequences, their tyrosine peptide maps indicate considerable similarity in other portions of their polypeptide chains. Thus the genes for their proteins may have evolved by duplication of a common ancestral gene. Another lymphocyte cell surface protein of MW 16,000 (p16) has also been characterised. Both p16 and p44 (the heavy chain of HLA-A,B antigens) have been compared with p29 and p34.     

1,2-di-n-butylhydrazine dihydrochloride carcinogenesis in mice

Summary A solution of 0.0625% 1,2-di-n-butylhydrazine dihydrochloride (1,2-DBH) was given continuously in the drinking water of 6-week-old randomly bred albino Swiss mice for the remainder of their lives. The treatment gave rise to tumors of the lungs, lymphoreticular tissue and kidneys.     

Nicotinamide administration alters the activities of hepatic microsomal mixed function oxidases

Summary Systemic action of nicotinamide significantly alters the activities of hepatic drug metabolizing enzymes. Male rats injected with nicotinamide have reduced levels of cytochrome P450, demethylases and aniline hydroxylase. The changes appear to be sex-dependent since in the case of female rats activities of p-nitroanisole-o-demethylase and aniline hydroxylase are enhanced whereas cytochrome P450 content remains unaltered.Authors gratefully acknowledge the encouragement given by Professor A.S. Paintal during the course of this investigation. One of us (J.K.B.) is grateful to the Council of Scientific and Industrial Research, New Delhi, for the award of a research fellowship.     

Similar effects of arginine-vasopressin and arginine-vasotocin on permeability of toad skin

Résumé Des crapauds ont été employés pour doser l'action des peptides neurohypophysaires sur la perméabilité de la peau. L'arginine⁸-vasopressine et l'arginine⁸-vasotocine ont en absence de Na⁺ le même effet. Elles augmentent les mouvements de l'eau, à doses variées, et leur action à toutes deux est 2000 fois plus puissante que celle de l'oxytocine. En presence de Na⁺ l'action de l'arginine⁸-vasotocine est 3 fois plus grande que celle de l'arginine⁸-vasopressine. Elles sont respectivement 120 fois et 40 fois plus puissantes que l'oxytocine.