Murine Salivary Gland Research Articles

Persistence during G1 of gamma ray- or mitomycin C-induced lesions eliciting SCE in murine salivary gland cells in vivo.

The efficiency of mitomycin C or gamma rays to induce SCE in early or late G1 was determined in synchronized murine salivary gland cells in vivo, as a measure of the capacity of this tissue to repair the lesions involved in SCE formation before S. The SCE frequencies induced by MMC in the first division (before BrdU incorporation) were significantly lower in the early G1 compared to the late G1, indicating some repair of SCE-inducing lesions. In the second division (after BrdU incorporation), there was no difference between SCE induced in early and late G1, indicating that MMC-induced lesions in such conditions are very persistent and not repairable during G1. The radio induced SCE frequency at early G1 was significantly lower than that observed in late G1, in cells irradiated after BrdU incorporation, suggesting that half of gamma ray-induced DNA lesions that elicit SCEs were repaired.

Extra-thymic immature T cells: development in polyoma virus-induced murine salivary gland tumors.

Lymphocyte infiltrates which occur in some polyoma virus-induced murine salivary epithelial tumors are characterized. The lymphocytic infiltrates within the salivary tumors resemble cortical thymocytes with the phenotype PNA+, Thy-1.2 bright, Ly-2+L3T4+, Ly-1 dim, H-2Kdim, KJ16-133-. The salivary lymphocytes showed proliferation based on analysis of RNA and DNA content. Because thymocytes lose the immature phenotype before leaving the thymus, we propose that the salivary tumor infiltrates result from the intra-tumoral differentiation of blood-derived prothymocytes into "cortical thymocytes". Histologic examination of the salivary tumors indicates expression of class II major histocompatibility antigen on the tumor epithelium which may be essential in establishing the extra-thymic T lymphocyte-inductive microenvironment within the tumor.

The potential usefulness of interleukin-2 activated bone marrow cells as an active therapeutic tool against cytomegalovirus infection in a bone marrow transplantation setting

Bone marrow transplantation (BMT) has been used in recent years for the treatment of immunodeficiency diseases, aplastic anemia, and leukemia. However, there are a number of serious problems and limitations associated with autologous or allogeneic BMT. One of these is an increase in opportunistic infections, of which cytomegalovirus (CMV) infection is one of the most important. Cytomegalovirus has been associated with more frequent deaths than any other single agent, with no reproducibly successful or therapy currently available. Recently usage of interleukin-2 or immunomodulation has been suggested as a powerful modality to combat infectious disease. In this study we showed that bone marrow activated in interleukin-2 for 2 days has the ability to lyse spleen cells infected for 3 days with murine CMV (acute infection model) or salivary gland cells infected for 7 days (chronic infection model), while nonactivated bone marrow or natural killer (NK) cells showed no such lysis. The majority of activated cells involved in lysis were antiasialo GM1-, Thy-1+/-, indicating a population of cells other than the natural killer-cell population involved.

The short-term effects of a single injection of isoproterenol on proliferation in the submandibular gland, parotid gland and oesophagus in vivo.

Mitotic and labelling indices were studied in the submandibular, parotid and oesophageal cells of male mice within the first 6 hr (but particularly within the 1st hr) of a single injection of isoproterenol or saline, using the metaphase arrest agent (vincristine) which was previously tested for efficacy in submandibular gland. There was a significant increase in the metaphase index of the salivary glands over control values 5, 15, 30, 45 and 60 min after isoproterenol. In contrast, there were no significant changes in the metaphase index of basal cells of the oesophagus. There was no significant change in the labelling index in isoproterenol-treated mice in comparison with saline-injected control animals. Possible explanations for the rapid mitotic response in murine salivary glands are considered; a rapid efflux from G2 into mitosis is thought to be the most likely.

Zinc-containing 7S-NGF complex. Evidence from zinc histochemistry for localization in salivary secretory granules.

7S-NGF is a pro-protein containing a neurotrophic subunit, beta-NGF, which has been localized by immunocytochemistry to the granules of granular convoluted tubule (GCT) cells in certain murine salivary glands [Watson et al., Anat Rec (1985) 213:365]. The 7S-NGF pro-protein contains zinc and is stabilized by zinc ions [Pattison and Dunn, Biochemistry (1976) 15:3696]. In the present work, dithizone, toluene sulfonamide quinoline (TSQ), and neo-Timm's methods for zinc were used to determine whether zinc histochemistry could be used to visualize the zinc associated with the 7S-NGF complex and, if so, whether zinc histochemistry might corroborate the reported localization of the 7S-NGF complex in GCT secretory granules. The results indicate that intensity of zinc staining varies with the reported variations in NGF levels in different salivary glands, and that the zinc is selectively concentrated in the GCT secretory granules. We suggest that zinc histochemistry may be a useful marker for the presence of the zinc-stabilized 7S-NGF pro-protein.

Prostaglandin synthesis by murine salivary glands

When submandibular-gland homogenate was incubated with radioactive arachidonic acid, three radioactive metabolites were detected by thin-layer chromatography; these were identical with the prostaglandins (PG) PGE 2, PGF 2α and PGI 2. Thromboxane A 2 (TXA 2) and PGD 2 were not found. The major cyclo-oxygenase products of the parotid and sublingual glands were also PGE 2, PGF 2α and PGI 2. The PGE 2 and PGI 2 synthetic activities of the submandibular gland were the highest of any tissue examined. This PGI 2 activity was about 1.5 times higher in male than in female mice.

Lectin binding patterns in salivary glands treated with amylase

Lectin binding patterns of ConA (Glc, Man), PNA and SBA (Gal, GalNAc), RCA-I (Gal) DBA (GalNAc), WGA (GlcNAc), and UEA-I (Fuc) in the major salivary glands of mice, rats, hamsters, and guinea pigs were reported using paraffin sections subjected to alpha-amylase treatment at 1, 3, and 6 h digestions. Lectin staining following treatment with amylase was generally enhanced in acinar, duct, and GCT cells. However, increasingly different reactions were obtained depending upon the lectins used, the various salivary glands from different specimens treated, and the different properties of the serous, mucous, and sero-mucous cells in the histologic sections. The lectins that demonstrated rather markedly increased staining were ConA, PNA, SBA, WGA, and UEA-I, whereas RCA-I and DBA increased little in comparison, or actually decreased. It appears from these findings that complex carbohydrates within murine salivary glands contained large amount of glucose, mannose, galactose, and N-acetyl galactosamine residues. The basement membranes of glandular cells in salivary glands demonstrated markedly positive ConA staining following alpha-amylase digestion.

Morphological and biochemical changes in mucous cells of the murine sublingual salivary gland during the carbamylcholine-induced secretory cycle

Changes in these cells have been evaluated over 6 h following cholinergic stimulation. Carbamylcholine administration resulted in the release of almost 50 per cent of secretory material within 15 min, which caused a reduction of 33 per cent in cell size. After 2 h the cells were depleted of secretory material. However, in the second hour the release of secretory material was accompanied by an enlargement of the nucleus, Golgi complexes and rough endoplasmic reticulum (RER), which suggests an elevation of biosynthetic activity. The enlargement of the RER was not the result of an increase in RNA, i.e. in the number of ribosomes, but of dilatation of its cisternal spaces. Before release took place, there was a continuous coalescence of secretory granules. After this extensive fusion, which is probably the result of an altered physiological state of the granule membrane and subsequent water uptake caused by cholinergic stimulation, the viscous mucins could be squeezed out, water transport is likely to assist in this ejection. Refilling of the mucous cells was almost complete within 6 h after stimulation.

Sex hormone involvement in the development of experimental virally induced murine salivary gland tumors.

Mice were given a single inoculation of polyoma virus at birth and then orchidectomised or oophorectomised. Unoperated groups received polyoma virus alone whilst further males received testosterone, and females received oestradiol thrice-weekly in addition to polyoma virus inoculation. All groups were then observed over the succeeding 370 days for the development of tumors of the submandibular and parotid salivary glands. Polyoma virus inoculation selectively induced salivary gland tumors in 70% of male animals and 30% of female animals given polyoma virus alone. Testosterone therapy increased the salivary tumor frequency from 69-90% whilst orchidectomy reduced the tumor frequency to 50%. Oophorectomy or oestrogen therapy did not significantly alter the salivary gland tumor frequency in females but oestrogen therapy did result in the development of second primary tumors of breast in 60% of female animals bearing salivary gland tumors. The role of androgens in the development of virally induced salivary gland tumors is discussed as are the possible mechanisms responsible for the development of second primary tumor of breast.

Effects of testosterone and its metabolites in relation to androgen-binding activity in murine submandibular salivary glands

The relative potencies of testosterone (T), testosterone propionate (TP) and other related steroids (5α-dihydrotestosterone, DHT; 5α-androstane-3α,17β-diol, α-diol; 5α-androstane-3β,17β-diol, β-diol) in restoring some morphological and functional characteristics of submandibular gland (SMG) were investigated in castrated mice. The steroids restored to near-control values the glandular weight and total protein content, α-diol and TP being the most effective compounds tested; with regard to proteolytic activity stimulation, β-diol was more effective than DHT. The α-diol metabolite was unique in significantly increasing DNA synthesis. In competition studies, α-diol and β-diol were ineffective in displacing the specifically bound [ 3H]-R1881 from the SMG androgen-binding macromolecules. Thus T can elicit its effects on SMG without the need of prior conversion to DHT; there must be alternative, receptorindependent mechanisms whereby α- and β-diol exert trophic/metabolic effects on murine SMG.

Chemical characterization of the two forms of epidermal growth factor in murine saliva

Extracts of murine salivary glands contain two molecular forms of epidermal growth factor, EGF I and EGF II (Petrides, P.E., Levine, A.E., Shooter, E.M. in: Peptides: - Synthesis, Structure and Function (Rich, D.H., Gross, E.eds.) p. 781 (1981]. We have identified both molecules not only in salivary gland extracts but also in saliva using only reverse phase liquid chromatography methodology. EGF I and II were isolated from submaxillary gland extracts in a ratio of 3:1 regardless of whether the classical isolation procedure or our rapid RPLC based technique was used. Both molecular forms were present in the same ratio in saliva of mice of both sexes when salivation was induced by epinephrine treatment of the animals. As judged by amino acid analysis and N-terminal sequencing salivary EGF I corresponds to the 53 amino acid sequence of murine EGF and EGF II is Des-ASN-EGF. The observation that EGF and Des-ASN-EGF are consecreted into saliva upon epinephrine stimulation implies a physiological role of EGF II which may be related to the high molecular weight EGF-complex.

A quantitative study on growth and cell population identification in murine salivary gland culture

Differentiation of neonatal salivary gland cell populations was studied in vitro using primary explant cultures. Growth on glass of the submandibular, sublingual and parotid salivary glands was optimal if the initial explant diameter was less than 0.4 mm and culture was in 199 medium plus 20 per cent newborn-calf serum. Growth was measured by planimetry of the area of cellular outgrowth as a monolayer with continuous cell contacts. Duct epithelial cells identified using ultrastructural, histochemical and immunological criteria, produced evidence of altered morphology by in-vitro conditions. Preservation of enzymic and antigenic markers of ductal epithelial cell origin in vitro irrespective of gross cell morphology allowed quantification of these cells in a mixed cell population.

Cellular origin of secretory granules in murine salivary glands

Cellular origin of secretory granules in murine salivary glands

Morphological changes in murine submandibular salivary glands after stimulation with autonomic drugs

Morphological changes in murine submandibular salivary glands after stimulation with autonomic drugs

A comparison of normal submaxillary gland proteins with proteins obtained from a transplantable murine salivary gland carcinoma (myoepithelioma)

A new transplantable murine salivary gland carcinoma (myoepithelioma) was further characterized by comparing total protein patterns with normal submaxillary qland proteins. Analysis by isoelectric focussing or by labelling studies with radioactive leucine showed considerable differences between tumour and normal proteins. In contrast, analysis of staining patterns after electrophoresis in sodium dodecyl sulphate containing gels revealed a striking similarity between normal proteins, tumour proteins and proteins obtained from metastatic growths. It thus appears that tumour proteins closely resemble the normal proteins from the tissue of origin with respect to molecular size as determined by electrophoretic mobility, while significant differences occur in charge and labelling kinetics.

A Comparative Study of the Effects of Cyclocytidine and Fluorocyclocytidine on Murine Submaxillary Salivary Glands

The clinical utility of 1-β-D-arabinofuranosylcytosine (araC), NSC 63878, a chemotherapeutic agent active against a number of acute leukemias and lymphomas, is compromised by the deamination of araC to arabinosyluracil, an inactive metabolite. This observation has led to the study of 2,2'-anhydro-l-β-D-arabinofuranosylcytosine (cyclocytidine, cycloC), NSC 145668, a structurally related, potent anti-tumor agent which is less easily deaminated than is araC. The fluorinated derivative of cycloC, 2,2'-anhydro-l-β-arabinofurano-syl-5-fluorocytosine (fluorocyclocytidine, F-cycloC), NSC 166641, also is an active chemotherapeutic in patients with acute leukemias, and may be most useful in subjects who are resistant to araC. The clinical advantages associated with cycloC are limited, however, by severe salivary gland discomfort and hypersalivation in patients receiving this compound. The present study was undertaken to characterize the cytopathologic alterations in murine submaxillary glands following cycloC therapy and to compare these observations with similar data from studies of mice treated with F-cycloC.

INTERFERON PRODUCTION IN VITRO BY CELLS INFECTED WITH THE MURINE SALIVARY GLAND VIRUS.

SummaryUsing a heterologous virus-cell system, an EMC virus interfering substance having many properties similar to those of interferon(3,4) was detected in the growth medium from mouse embryo cell cultures infected with the murine salivary gland virus. The interfering material was non-dialyzable, heat labile at 60°C for one hour, stable at pH 2, not affected by MSGV antiserum, not sedimented at 90,000 X g, and was active in a cell system unable to support MSGV replication. In infected cultures, the rise in MSGV titer was associated with a corresponding rise in the interferon activity. Efforts to relate interferon production to latency in vivo are in progress.The authors would like to thank Mr. John Gehrke for his excellent technical assistance.

EFFECT OF AMINOPTERIN ON THE REPLICATION OF THE MURINE SALIVARY GLAND VIRUS.

RECENT evidence has indicated that the synthesis of DNA viruses is prevented by specific DNA inhibitors while the synthesis of RNA viruses is not affected1–3. On this basis, therefore, experiments were undertaken to determine if aminopterin (4 amino-pteroylglutamic acid), a folic acid antagonist, would block the replication of the murine salivary gland virus (MSGV) in tissue culture. In the presence of adenine and glycine the antifolic drugs have been shown specifically to block the formation of DNA in mammalian cell cultures3. Under such conditions the antifolics will inhibit replication of DNA but not RNA viruses2,3.

CHARACTERISTICS OF A PLAQUE METHOD FOR THE MURINE SALIVARY GLAND VIRUS.

CHARACTERISTICS OF A PLAQUE METHOD FOR THE MURINE SALIVARY GLAND VIRUS.