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Biomedical subjects

H Mörnstad

Publications and source records attributed to H Mörnstad.

At least 37 records · Page 2Linked to original sources
PubMed1989

Effects of chronic stimulation of salivary gland beta-adrenoceptors on saliva composition and caries development in the rat.

The effects of long-term beta-adrenoceptor stimulation or inhibition on parotid and submandibular glands, saliva secretion, and caries development were studied. Groups of rats were treated daily with: 0.5 or 5 mg/kg body weight of isoproterenol (IPR), 0.5 or 5 mg/kg bw propranolol (PRO), or saline. After 42 days, saliva was collected and analyzed for secretion rate, total protein, amylase, sialic acid and electrolytes. Total protein and amylase in saliva decreased and potassium increased in the high IPR group. Phosphate increased in both IPR groups and decreased in the high PRO group. The average weight of parotid glands increased 3.7 times in the high IPR group and 1.8 times in the low IPR group. Amylase and total protein in parotid gland extracts decreased in both IPR groups. The submandibular gland weight increased 1.5 times in the high IPR group. Total protein decreased in the high IPR group. There was no difference in caries development.

Amylases↗
PubMed1988

Effect of long-term isoproterenol treatment on caries development in the rat using a low-cariogenic model.

Forty-eight Sprague-Dawley rats were divided into four groups. Two groups were injected daily with saline (groups 1 and 2) and two groups with isoproterenol (0.5 mg/kg body weight, groups 3 and 4) beginning at the age of 21 days. Groups 1 and 3 were each day fed nine subsequent sucrose-containing meals followed by eight starch-containing meals. Groups 2 and 4 were fed alternating sugar- or starch-containing meals, totally 17 meals per day. The animals were sacrificed after 14 weeks. At the end of the experiment, the animals in the isoproterenol groups had higher body weights. Caries development increased significantly after isoproterenol treatment. The diet regimen with alternating sugar- or starch-containing meals increased caries development, particularly in combination with isoproterenol treatment. Using low cariogenic conditions, we found that an unspecific beta-agonist (isoproterenol), given posteruptively at a low dose, enhances caries development.

Animals↗
PubMed1986

Acute effects of different antidepressant drugs on saliva secretion and accommodation range.

In a double blind controlled cross-over trial on 20 healthy volunteers, the anticholinergic side-effects of single doses of amitriptyline (75 mg), zimelidine (100 mg), maprotiline (75 mg), and placebo were compared. Anticholinergic side-effects were determined by means of self-rating of dryness in the mouth (visual analogue scale), determination of unstimulated and stimulated saliva secretion rate and accommodation range. There were no significant effects recorded after intake of placebo, which supports the test-retest reliability and the validity of the methods. Amitriptyline produced the most pronounced anticholinergic side-effects followed by maprotiline and zimelidine in decreasing order. There were no significant correlations between self-rating of dry mouth and saliva secretion rate or between accommodation ability and saliva secretion rate.

Adult↗
PubMed1986

Long-term effects of two principally different antidepressant drugs on saliva secretion and composition.

In a double-blind, controlled, cross-over trial on 10 healthy volunteers, the effects of daily doses of maprotiline (75 mg) and zimelidine (100 mg) over a 14-day period were tested on saliva secretion rate and saliva composition. Based on current knowledge of salivary gland physiology and the difference in specificity between the two drugs, differences in salivary gland response could be expected. Since both drugs have anticholinergic effects which influence saliva secretion rate, the measured component concentrations had to be recalculated with regard to dependencies of secretion rate. Maprotiline, but not zimelidine, caused strong inhibition of secretion rate and accommodation ability. Maprotiline consistently caused around 50% increases in concentrations of the following saliva components: protein, amylase, fucose, hexose, sialic acid and potassium. The effects of zimelidine were less pronounced and resulted in initial increases of most organic components. 14 and 18 h after the intake of the drug these increases had disappeared and some of the components instead showed decreased concentrations. The results are consistent with current theories about facilitated serotoninergic and noradrenergic transmissions during treatment with antidepressants.

Absorption↗
PubMed1986

Acute effects of some different antidepressant drugs on saliva composition.

In a double-blind controlled cross-over trial on 20 healthy volunteers, the acute effects of single doses of amitriptyline (75 mg), zimelidine (100 mg), maprotiline (75 mg), and placebo were tested on saliva composition. From the current knowledge of the physiological regulation of the salivary glands and the different specificities of the three drugs, different responses from the salivary glands could be expected. As all three drugs have anticholinergic effects that influence the saliva secretion, the concentrations of secreted saliva components had to be recalculated with regard to changes in secretion rate. No changes in saliva composition were recorded after the intake of placebo. The most pronounced changes were observed after amitriptyline intake. Amitriptyline caused increases in the concentrations of proteins, glycoproteins, calcium and potassium. Zimelidine initially decreased the concentrations of glycoproteins and increased the concentration of calcium. Maprotiline increased the concentrations of proteins and sodium. Most of the results fit in well with the theories about facilitated serotoninergic and adrenergic transmission during treatment with antidepressants.

Adult↗
PubMed1986

Saliva secretion rate and saliva composition as a model to determine the effect of antidepressant drugs on cholinergic and noradrenergic transmission.

Three principally different antidepressant drugs--amitriptyline (with effects on both noradrenaline and serotonin reuptake), maprotiline (a selective inhibitor of reuptake of noradrenaline) and zimelidine (a selective inhibitor of reuptake of serotonin) were tested after a single dose and, as concerns maprotiline and zimelidine, after long-term use in healthy volunteers as regards the effects on saliva secretion rate and saliva composition. Amitriptyline gave a strong decrease in both unstimulated and stimulated saliva secretion rate, indicating a strong anticholinergic effect, and a strong increase in the activity of amylase and the content of protein, fucose and hexose in saliva, indicating a strong agonistic effect on noradrenaline transmission. Maprotiline gave an intermediate decrease in saliva secretion rate, and the effect remained after 14 days of treatment. Single doses gave increases in saliva amylase activity and protein content. After 14 days this effect was increased, and there was also a pronounced increase in fucose and hexose content indicating a strong agonistic effect on noradrenaline transmission. Zimelidine gave a low decrease in saliva secretion rate, indicating a mild anticholinergic effect. No certain effect on the saliva composition could be settled after a single dose, but after 14 days there were consistent increases in amylase activity and protein, fucose and hexose content, indicating a facilitation of noradrenaline transmission. Zimelidine as well as its active metabolite, norzimelidine, are selective inhibitors of serotonin reuptake. The action of zimelidine is discussed in view of recent hypotheses about a modulating serotoninergic influence on the noradrenergic system.

Adult↗
PubMed1985

Cyclic adenosine 3', 5'-monophosphate levels in human parotid saliva at different secretion rates.

Seventy-four samples of unstimulated and stimulated parotid saliva were collected from 12 healthy male volunteers. The secretion rates and cAMP concentrations were determined. The secretory rate ranged from 0.01 to 1.03 ml/min/gland. The concentration of cyclic AMP varied from 1.6 to 31.9 pmol/ml. The concentration of cAMP was 10.0 +/- 6.5 pmol/ml in unstimulated saliva and 3.8 +/- 1.6 pmol/ml in stimulated saliva. A curvi-linear relationship existed between secretory rate and cyclic AMP concentrations, and the best-fitting regression equation was y = 2.06 + 0.5/x, where y = concentration of cyclic AMP and x = secretory rate.

Adult↗
PubMed1985

Oral conditions in patients receiving long-term treatment with cyclic antidepressant drugs.

The function of the salivary glands, the caries situation, and pathological alterations of the oral mucosa of 32 patients, 20 dentulous and 12 edentulous, who had received long-term treatment (median 5.5 years) with cyclic antidepressant drugs were studied. Anamnestic information on dry mouth problems was recorded. Although a normal secretion rate for stimulated saliva was recorded in about 50% of the patients all but four complained over dry mouth. The majority of the patients had low values of salivary buffer capacity, high numbers of Streptococcus mutans and lactobacilli in the saliva, and poor oral hygiene. All except two patients had received dental care a year or less before the time of examination. Nevertheless 72% of the patients showed pathological alterations of their oral mucosa and 55% of the dentulous patients had new caries lesions. From an evaluation of the caries risk it was concluded that about half of the dentulous patients had a high caries risk, which seemed to be emphasized if combinations of psychotherapeutic drugs were used. It is recommended that patients receiving treatment with antidepressant drugs should be given an individually related dental prophylactic programme.

Adult↗
PubMed1982

Multiple forms of acid phosphatase in rat secretory enamel organ.

Acid phosphatase activity was studied biochemically in homogenates of secretory enamel organs from the rat. Incubations with crude homogenate failed to show distinct pH optima or kinetics characteristic for single enzymes. Crude homogenate activity was strongly inhibited by concentrations higher than 1 mM of NaF and Na-tartrate, and higher than 10 mM of ZnSO4 and para-bromotetramisole oxalate. 10 mM MgCl2 gave a slight stimulation. CaCl2, KCl and EDTA were uneffective. Electrophoretic separation of the crude homogenate acid phosphatase on Triton X-100 containing polyacrylamide gel demonstrated the presence of at least three multiple forms of the enzyme. Two of them showed distinct pH optima at pH 4.4. The third one showed a broad pH plateau in the acid pH range. Kinetic studies of the three forms indicated single enzyme reactions. Two forms had electrophoretic mobilities similar to alkaline phosphatase. One form could be solubilized only after Triton X-100 treatment. All forms were strongly sensitive to 10 mM NaF when added to the reaction mixture. The sensibility to 10 mM ZnSO4, CuSO4, Na-tartrate and para-bromotetramisole oxalate differed between the different forms.

Acid Phosphatase↗
PubMed1982

Oral carcinomas associated with snuff dipping. Some clinical and histological characteristics of 23 tumours in Swedish males.

Some clinical and histological characteristics of 23 oral carcinomas in the anterior vestibulum of snuff dipping Swedish males with an average age of 76 years were investigated. Examples of verrucous carcinomas as well as of ordinary, usually verrucoid but also ulcerating, squamous cell carcinomas were encountered. Widespread oral leukoplakia and second primary carcinoma--oral or other--was present in 5 and 6 cases respectively, and occurred together in 3 of these. Eleven cases out of 19 available for additional sectioning and staining showed candidal infection.

Aged↗
PubMed1981

Qualitative changes in saliva composition after short-term administration of imipramine and zimelidine in healthy volunteers.

Ten healthy volunteers participated in a double-blind controlled, randomized, cross-over trial, where the effects of the antidepressant drugs imipramine (75 mg/day) and zimelidine (100 mg/day and 200 mg/day) on saliva secretion rate and saliva composition were tested. The saliva secretion decreased and qualitative changes were found. Imipramine (75 mg/day) and zimelidine (200 mg/day), but not zimelidine (100 mg/day), increased buffer capacity and the components of the salivary glycoproteins (sialic acid, fucose, hexoses). Total proteins, amylase, secretory component and electrolytes (Na+, K+, Ca++, PO43-) did not change significantly.

Adult↗
PubMed1978

Calcium-stimulated ATPase activity in homogenates of the secretory enamel organ in the rat.

The activity of calcium-stimulated ATPase (E.C. 3.6.1.3) in homogenates of the secretory enamel organ of rat incisors was studied biochemically. ATP hydrolysis was estimated from the amount of inorganic phosphate liberated. An analysis of the total degradation of ATP was initially performed to ensure that the enzyme assays pertained to the original substrate, ATP, and were not influenced by reaction products formed. Standard incubations were run in tris-maleate buffer, pH 8.2, with 3 mM ATP, 3 mM Ca2+ and 0.5 mM R 8231 at 37 degrees C. The presence of R 8231 was necessary to inhibit nonspecific alkaline phosphatase. The calcium-stimulated ATPase was completely inhibited when heated at 55-60 degrees C for 5 min. The pH optimum was found to be 8.2. The hydrolysis was substantially dependent on Ca2+ and was fastest when the ATP:Ca2+ ratio was 1:1. High substrate concentrations inhibited the hydrolysis. The addition of 1 mM Zn2+ and Ni2+ to the incubation medium markedly inhibited the hydrolysis as did, though less strongly, p-hydroxymercuribenzoate, oligomycin, EDTA and ruthenium red. l-Cysteine, mercaptoethanol, iodoacetic acid and sodium azide were without effect. F- was without effect unless added to a final concentration above 15 mM to media where Ca2+ had first been allowed to react with ATP.

Adenosine Triphosphatases↗
PubMed1978

Demonstration of a K+-stimulated and ouabain-sensitive p-nitrophenyl phosphatase activity in enamel-and dentin-forming tissues in the rat.

p-Nitrophenyl phosphate hydrolysis was studied at neutral pH with tissue preparations of the rat secretory and maturation enamel organs and dental pulp. By introduction of inhibitors to nonspecific alkaline phosphatase activity and stimulants to the K+-stimulated and ouabain-sensitive p-nitrophenyl phosphatase activity, the latter enzyme activity could be demonstrated. This enzyme activity is generally held to be representative of the enzyme sodium- and potassium-stimulated adenosine triphosphatase. The K+-stimulated activity was magnesium dependent and highly sensitive to fluoride. It was inhibited completely by 3 mM fluoride in the incubation medium and about 1 mM produced half the maximum inhibition. The K+-independent enzyme activity was inhibited 50-60% by fluoride in concentrations between 3 and 15 mM. The high fluoride sensitivity of the K+-stimulated activity may perhaps help to explain the vulnerability of dental tissues to fluoride.

4-Nitrophenylphosphatase↗