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Salivary glands and cardiac ventricles were examined after chronic administration of pharmacological doses of isoproterenol (ISO) to young adult female rats. Enlargement of glands was observed, generally confirming previous reports. Enlargement of ventricles also occurred. Salivary glands were differentially affected, with parotid showing the most, and sublingual the least enlargement. Histological examination revealed increase in cell size sufficient to account for the increase in organ weight, although some mitotic activity was noted. Determination of water, electrolyte, and amylase content of glands indicated the hypertrophy is not due simply to water imbibition; changes in gland composition, when seen, were generally reminiscent, in magnitude and direction, of those occurring ordinarily during function activity. Function after chronic treatment with ISO was little affected; reduction in flow rate after pilocarpine was the major change observed in enlarged glands. Changes in gland and ventricle size and gland composition and function, induced by chronic ISO treatment, were largely reversible by withdrawal of the drug. It appears that in the adult, isoproterenol effects increases in organ size mainly by increase in cell size.

789part of a different molecule. Unpublished observations, indeed, indicate that there is a difference in CA from E. coZi 014 and from other bacteria, for CA from the former is largely insoluble and that from the latter soluble in 85% ethanol.The present observations of the inhibitory effect of lipopolysaccharides, and probably of lipoid A as well, on the CA antibody response of the rabbit appear to explain the poor immunogenicity of CA present in the bacterial cells and in crude supernates from organisms other than E. coli 014. Moreover, eventual elucidation of the mode of action of lipopolysaccharides as inhibitors of the 3CA antibody response may throw light on basic mechanisms of antibody formation.Summary. A common antigen (CA) is present in many species and serogroups of enteric bacteria, but only the antigen from E. coli 014 engenders CA antibodies in the rabbit upon intravenous injection. The ethanol soluble fraction of the former, however, induces the formation of CA antibodies. The present study has revealed that lipopolysaccharides (endotoxins) inhibit this CA antibody response. This inhibition was observed regularly when CA and lipopolysaccharides were injected as mixtures, but not when administered separately, although simultaneously, into different veins. Injection of mixtures prepared in ethanol were even less immunogenic than those prepared in water. A single preparation of lipoid A also inhibited the CA antibody response. It is postulated that the p r immunogenicity of enteric bacteria, other than E. coZi 014, is due to the inhibitory effect of the lipopolysaccharide on the fully immunogenic CA. 1. Kunin, 1C. M., Beard, M. V., Halmagyi, N. E., PROC. SOC. E n .

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Inulin, sodium, potassium and chloride levels were determined on serum and submaxillary, parotid and pancreatic glands of inulin-administered nephrectomized rats. Methods of tissue preparation and analysis were examined in some detail. From data obtained, volumes of inulin and electrolyte distribution were calculated. Volumes of distribution in submaxillary, parotid and pancreatic glands, in that order, were, for inulin, 198 ml/kg, 257 ml/kg and 209 ml/kg; for sodium, 232 ml/kg, 318 ml/kg and 275 ml/kg; and, for chloride, 365 ml/kg, 460 ml/kg and 388 ml/kg. Comparison of these values led to the conclusion that intracellular sodium in these glands is possible and that intracellular chloride is likely. Intracellular potassium seems present in concentration similar to that in mammalian muscle. From electrolyte data and levels of amylase in parotid gland and its secretion, it is speculated that parotid secretion could be formed from a small fraction (approx. 10%) derived from unmodified intracellular fluid to which is then added solution having electrolyte composition of extracellular fluid. The closely isotonic secretion of rat parotid gland can thus be predicted without assuming appreciable reabsorption of electrolytes or water.