Salivary gland hyperglycemic factor: an extrapancreatic source of glucagon-like material

Extracts of homogenates of rat, mouse, rabbit, and human submaxillary salivary glands contain a significant quantity of a material with glucagon-like immunoreactivity. Fractionation of this material on columns of Sephadex G-100 reveals a single peak immediately following a gamma globulin marker but in advance of a rat growth hormone marker, crystalline amylase, and isotopically labeled porcine insulin and glucagon. This material, which is urea stable, shows identical immunoassay dilution curves when measured with the highly specific K-30 glucagon antiserum. Study of paired glands in vitro shows that low concentrations of glucose stimulate and high concentrations of glucose suppress release of this material. Arginine promotes brisk release in vitro. Somatostatin does not influence arginine-stimulated secretion and insignificantly suppresses basal release in vitro. These findings lend support to previous speculations that the salivary glands may possess endocrine as well as exocrine functions. Salivary gland glucagon may also be the source of circulating glucagon recently reported in pancreatectomized and eviscerated rats.

Hemangiomas of the salivary glands

Five salivary gland hemangiomas in adults are reported. The feasibility of preoperative diagnosis on clinical and radiologic grounds is emphasized. Adult hemangiomas are of the cavernous type and can be differentiated from infantile capillary hemangiomas clinically as well as histologically. Cavernous hemangiomas in the adult should be treated by surgical excision.

The mercury(II)-induced aquation of trans-Chloroamminebis(dimethylglyoximato)cobalt(III) complex

The pseudo first-order rate constants for the mercury(II)-induced aquation of trans-[Co(Hdmg)2(NH3)Cl] (Hdmg = dimethylglyoximate ion) have been measured in aqueous and aqueous ethanol solutions (ethanol- water mole ratio 1 : 5.1) containing various excess amounts of mercury(II)ion at 273.2 K. Association constants of the complex formed with mercury(II) ion and rate constants for dissociation of the activated complex in both solutions have been calculated. The kinetic results are discussed in terms of formation of an activated complex Co-C1-Hg, followed by a simple rate-determining aquation in which HgCl+ acts as the leaving group.

GALVANIC STRESS POTENTIALS OF METALS

The electrode potential of silver, brass, and steel wires under tensile stress have been measured in aqueous solutions of silver nitrate, copper sulphate, and ferrous sulphate, respectively. The stress potentials were continuously measured with a stabilized d-c. microvolt amplifier which made possible the study of the transient and the steady-state period during loading and unloading. The stressed silver and steel electrodes were cathodic with respect to the reference electrode, and the e.m.f. was approximately a linear function of the stress. The slope of the e.m.f.–stress curve for silver increased with decrease in electrolyte concentration. The stressed brass electrode was anodic with respect to the reference electrode and the e.m.f. varied linearly with stress only for 1 N CuSO4.