Isolation and characterization of a protein corresponding to mKlk-11 clone from male mouse submandibular gland

A protein corresponding to the predicted genomic sequence of clone mKlk-11 has been characterized from mouse submandibular gland. This protein was purified by reverse-phase high-performance liquid chromatography from the submandibular glands of normal and hypertensive mice. The protein was not detected in the submandibular gland of mice selected for low blood pressure. It consists of three fragments starting at the residues 1, 98, and 141 of the predicted sequence of clone mKlk-11. The cleavage of beta-lactoglobulin (between residues 20 and 21, Tyr-Ser, and 40 and 41, Arg-Val) and a synthetic renin substrate tetradecapeptide (residues 4 and 5, Tyr-Ile) by the protein corresponding to clone mKlk-11 showed both tryptic- and chymotryptic-type cleavages. The possibility of this protein's involvement in the regulation of local blood flow is raised.

Left ventricular mural bacterial endocarditis: diagnosis by transesophageal echocardiography

An unusual case of staphylococcal endocarditis with a vegetation attached to the left ventricular myocardium is described. No valvular vegetations are present. The diagnosis was made by transesophageal echocardiography. The patient had no chronic debilitating disease, nor was she immunosuppressed.

Exogenous melatonin: morphology and kallikrein activity of male Syrian hamster submandibular gland

Seven weeks of daily melatonin administration resulted in substantial reduction of convoluted duct cell granule population and kallikrein activity. Some reduction of intercalated duct cell granules was also observed. Testes weight and size was also dramatically reduced. All these changes were not observed after three weeks of melatonin injection.

Radioautographic visualization of differences in the pattern of [3H]uridine and [3H]orotic acid incorporation into the RNA of migrating columnar cells in the rat small intestine

The epithelium of rat small intestine was radioautographed to examine whether RNA is synthesized by the salvage pathway as shown after [3H]uridine injection or by the de novo pathway as shown after [3H]orotic acid injection. The two modes of RNA synthesis were thus investigated during the migration of columnar cells from crypt base to villus top, and the rate of synthesis was assessed by counting silver grains over the nucleolus and nucleoplasm at six levels along the duodenal epithelium--that is, in the base, mid, and top regions of the crypts and in the base, mid, and top regions of the villi. Concomitant biochemical analyses established that, after injection of either [5-3H]uridine or [5-3H]orotic acid: (a) buffered glutaraldehyde fixative was as effective as perchloric acid or trichloracetic acid in insolubilizing the nucleic acids of rat small intestine; (b) a major fraction of the nucleic acid label was in RNA, that is, 91% after [3H]uridine and 72% after [3H]orotic acid, with the rest in DNA; and (c) a substantial fraction of the RNA label was in poly A+ RNA (presumed to be messenger RNA). In radioautographs of duodenum prepared after [3H] uridine injection, the count of silver grains was high over nucleolus and nucleoplasm in crypt base cells and gradually decreased at the upper levels up to the villus base. In the rest of the villus, the grain count over the nucleolus was negligible, while over the nucleoplasm it was low but significant. After [3H]-orotic acid injection, the number of silver grains over the nucleolus was negligible at all levels, whereas over the nucleoplasm the number was low in crypt cells, but high in villus cells with a peak in mid villus. The interpretation is that, except for a small amount of label incorporated into DNA from either precursor by crypt cells, the bulk of the label is incorporated into RNA as follows. In the crypts, cells make almost exclusive use of uridine, that is, of the salvage pathway, for the synthesis of ribosomal RNA in the nucleolus and of messenger and transfer RNA in the nucleoplasm. However, when cells pass from crypt to villus, they mainly utilize orotic acid--i.e., the de novo pathway--for the synthesis of messenger and transfer RNA within the nucleoplasm.

The localization of kallikrein in the dog and guinea-pig submandibular glands

In the dog and guinea-pig submandibular glands kallikrein seems to be present in the striated duct cells. Following sympathetic nerve and in vivo isoproterenol stimulation of the dog and guinea-pig submandibular gland respectively, there is a reduction of kallikrein concentration. Ultrastructurally this reduction corresponds to the decrease of straited duct secretory granules in both species. Parasympathetic stimulation also causes some release of kallikrein from both species.

Demilune cells of the cat submandibular gland; an unlikely source of kallikrein

The functional significance of kallikrein in the salivary gland remains unclear partially because of uncertainty over its precise cellular localization. Kallikrein was thought to originate in acinar cells, until recent evidence from cat and rat localized it primarily to the ducts. The possibility that salivary kallikrein may also be located in demilune cells was investigated in this study. - The total kallikrein content of cat submandibular glands was found to be substantially reduced by sampathetic nerve stimulation; whereas parasympathetic stimulation had no significant effect. These biochemical findings did not correlate with morphological studies that revealed almost complete depletion of the demilune cells secretory granules after stimulation of either division of the autonomic nerve supply. This lack of correlation makes it unlikely that kallikrein is present in the demilune cell secretory granules.

Effect of nerve stimulation, denervation, and duct ligation, on kallikrein content and duct cell granules of the cat's submandibular gland

Various procedures which reduce or deplete the kallikrein content of the cat's submandibular gland correspondingly reduce the number of apical granules in the striated duct cells. The kallikrein content is greatly reduced after chronic parasympathetic but not after sympathetic nerve section which suggests that the parasympathetic innervation is required for synthesis or storage of this enzyme.

Autonomic nerve stimulation, kallikrein content anc acinar cell granules of the cat's submandibular gland

The parasympathetic and sympathetic nerves to the submandibular gland of the anaesthetized cat were stimulated under specific conditions. 1. It was possible to decrease the kallikrein (kininogenase) content of the gland by as much as 90-95% by sympathetic nerve stimulation. In such a gland the appearance and concentration of secretory granules in the acinar cells were indistinguishable from an unstimulated gland. 2. Parasympathetic nerve stimulation, in contrast to sympathetic nerve stimulation, whilst having no significant effect on the kininogenase content of the gland, resulted in the disappearance of a great majority of the acinar granules. 3. These results demonstrate that the acinar granules in the submandibular gland of the cat are not a significant source of kallikrein. 4. Our experiments also failed to indicate any obvious correlation between the granules of the demilune cells and the kallikrein content of the gland. 5. The possibility is raised that kallikrein is located in the cells of the striated ducts.

Lemon-peel pectin. III. Fractionation of pectic acids from lemon-peel and lucerne

The pectic acids formed on saponification of lemon-peel pectins C and L have been fractionated by graded precipitation with sodium acetate. The results of analytical and electrophoretic studies on the pectic acid fractions have been interpreted as being typical of those of the fractionation of chemically homogeneous polydisperse systems. Similar fractionations of lucerne polysaccharides have indicated the presence of a single component in pectic acid A and of two components in pectic acid B. The nature of polysaccharide heterogeneity in pectic acid preparations is discussed.