Changes in Protein Secretion by Rat Submandibular Glands in Response to Isoproterenol, a-Methylnoradrenaline, and Clonidine during Post-natal Development

Tanaka, E.; Habu, Tetsuya; Letic-Gavrilovic, Anka; Abe, Kimio

doi:10.1177/00220345900690011001

Cited by 15 publications

(7 citation statements)

References 35 publications

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“…We are not certain why protease activities were significantly reduced by these blockers, which did not cause the a-type proteins to be replaced by the n-type proteins. It may be that some estero-proteases within the a-type proteins are also secreted in response to f-adrenergic stimuli, as shown by us previously (Tanaka et al, 1990a).…”

Section: Discussionsupporting

confidence: 53%

“…These results were consistent with our results on the types of proteins secreted by the submandibular glands of rats. Most proteases and the oxtypes of proteins appear to be secreted in response to ax- (Matthews, 1974;Abe and Dawes, 1978;Tanaka et al, 1990a). However, metoprolol (1 and 5 mg/kg), ICI 118551 at all doses, propranolol (1, 5, and 10 mg/kg), and yohimbine (10 mg/kg) significantly reduced the protease activity.…”

Section: Discussionmentioning

confidence: 97%

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The Effects of Tyramine on Salivary Flow Rate and Protein Secretion by Rat Submandibular Glands

et al. 1993

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The effects of different doses of p-tyramine injected i.v. and i.p. on salivary flow rates and proteins secreted by the submandibular glands of rats were studied with and without various types of autonomic blockers and two enzyme inhibitors. The salivary flow rates and the amounts of protein secreted progressively increased with increasing doses injected both i.v. and i.p., whereas they were dramatically reduced with all autonomic blockers except the lowest doses of beta-blockers, atropine, and yohimbine. Salivation in response to p-tyramine injected i.v. and i.p. was completely abolished by simultaneous injections of both prazosin and propranolol. The concentration of protein was not dose-dependent and was not reduced by yohimbine and phenoxybenzamine at almost all doses used. However, prazosin significantly increased the protein concentration. Protease activities were dose-dependent but were significantly reduced with alpha-blockers other than yohimbine, and with most beta-blockers. The proteins secreted in response to p-tyramine at all doses injected i.v. and i.p. were of the alpha-type except with the lowest dose injected i.p. However, the alpha-type was completely replaced by the beta-type in the presence of all alpha-blockers except yohimbine, but not with beta-blockers, atropine, or two enzyme inhibitors. Pargyline, a monoamine-oxidase inhibitor, but not disulfiram, a dopamine-beta-hydroxylase inhibitor, affected all parameters except the type of protein. Thus, p-tyramine may activate both the alpha 1- and beta 1-adrenoceptors in the submandibular glands of rats directly or indirectly.

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Section: Discussionsupporting

confidence: 53%

Section: Discussionmentioning

confidence: 97%

The Effects of Tyramine on Salivary Flow Rate and Protein Secretion by Rat Submandibular Glands

et al. 1993

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“…Clonidine (10 µg/kg) given intravenously reduced rat submandibular gland salivation induced by norepinephrine, methacholine, or substance P, but at higher doses (100-3,000 µg/kg) actually elicited secretion [Kaniucki et al, 1984]. Single, intraperitoneal injections of high-dose clonidine (5-10 mg/kg) also elicited salivary secretion in rats [Tanaka et al, 1990;Yu et al, 1987]. The secretory response to clonidine was almost completely abolished by a low dose of prazosin (an α 1 -adrenergic antagonist) and was not affected by the α 2 -adrenergic antagonist yohimbine, suggesting the secretory response was mediated by α 1 -adrenergic receptors.…”

Section: Discussionmentioning

confidence: 99%

“…These doses of clonidine were chosen because they have been reported high enough to induce hypotensive effects in rats [Naruse et al, 1994], but below the level generally found to nonselectively stimulate α 1 -adrenergic receptors [van der Laan and van't Land, 1992] and induce salivary secretion [Yu et al, 1987;Tanaka et al, 1990;Yu, 1992].…”

Section: Methodsmentioning

confidence: 99%

The Effect of Chronic Clonidine Administration on Salivary Glands and Caries in the Rat

Watson

Pearson²,

Bowen

2000

Caries Res

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Clonidine is a widely prescribed, centrally acting antihypertensive with proposed pharmacologic mechanisms of stimulation of central postsynaptic α₂–adrenergic receptors and agonist activity at presynaptic α₂–adrenergic receptors, interfering with peripheral regulation of norepinephrine and acetylcholine release. Both of these mechanisms are capable of adversely influencing salivary output and composition, potentially leaving an individual with increased caries risk. The purpose of the present study was to determine the effect of chronic administration of clonidine on saliva, salivary glands, and caries in rats. Sprague–Dawley rat pups were infected with Streptococcus sobrinus, given Diet 2000 and 10% sucrose water ad libitum, and either desalivated, or treated with clonidine HCl (125 or 250 μg/kg administered daily for 28 days by means of osmotic minipumps), or assigned as controls. There were no statistical differences in stimulated parotid or submandibular gland salivary output or sublingual gland weights among the groups. The weight of the submandibular glands as a percent of total body weight was significantly decreased in animals that received clonidine when compared with controls. Sulcal caries scores in both clonidine groups and smooth surface caries scores in the high clonidine group were increased when compared with control animals. Positive control animals (desalivated) had significantly higher caries scores than all other groups. These data show that chronic administration of clonidine significantly decreases submandibular gland weight and increases susceptibility to dental caries.

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“…Saliva, extracts, and sera analyses Saliva samples were analyzed for total protein by the method of Lowry et al (1951) with casein as a standard and then, after the addition of Na3-EDTA to avoid subsequent precipitation of Ca proteinate (Dawes, 1965), were kept frozen at -20°C until lyophilization could be carried out. After reconstitution of the lyophilized saliva, 15% native polyacrylamide gel electrophoresis and isoelectric focusing electrophoresis by the PhastSystem (Pharmacia, Uppsala, Sweden) on both pH 3.5 to 5 and 3.5 to 9 gels were carried out, as described previously (Abe and Dawes, 1985;Tanaka et al, 1990;Okina et al, 1993). After isoelectric focusing electrophoresis, the gels were stained with silver (Heukeshoven and Dernick, 1985) or Coomassie Brilliant Blue R (Okina et al, 1993), whereas the polyacrylamide gels were stained with Wool Fast Blue BL (Abe and Dawes, 1978).…”

Section: Methodsmentioning

confidence: 99%

Abnormally High Levels of Cystatin S in Submandibular Glands, Saliva, and Gingiva of Plaque-resistant Rats

et al. 1998

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To identify salivary biomarkers of periodontal diseases, we used plaque-resistant and -susceptible rats as animal models. The levels of salivary cystatin S in saliva, salivary glands, and gingiva were tested in Nembutal-anesthetized young and adult plaque-resistant and -susceptible rats of both sexes with and without chronic treatment with isoproterenol. Isoproterenol was injected i.p. once a day for 4 or 6 consecutive days. Isoelectric focusing electrophoresis by the PhastSystem and the western blotting method were used to separate different proteins and to identify a salivary cystatin S band in these samples. The expression of salivary cystatin S mRNA was also determined by the northern blotting method. Depending upon the types of agonists, a few differences were observed in secretory functions between both strains of rats in both sexes, but the levels of salivary cystatin S in saliva elicited from the submandibular gland and in the extracts of the submandibular glands and gingiva were significantly higher in plaque-resistant rats when compared with those of plaque-susceptible rats in both sexes. However, no significant difference was seen between the strains after chronic treatment with isoproterenol. The N-terminal 26-amino-acid sequence of salivary cystatin S purified from submandibular saliva of plaque-resistant rats was identical with that purified from submandibular saliva of Sprague-Dawley rats subjected to chronic treatment with isoproterenol. The expression of salivary cystatin S mRNA was dramatic in the submandibular glands of the plaque-resistant rats and in the submandibular glands of Wistar rats subjected to chronic treatment with isoproterenol, but not in those of plaque-susceptible rats. These results suggest that salivary cystatin S might be a good biomarker in distinguishing between the two strains of rats and that its concentration is correlated with plaque resistance.

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Changes in Protein Secretion by Rat Submandibular Glands in Response to Isoproterenol, a-Methylnoradrenaline, and Clonidine during Post-natal Development

Cited by 15 publications

References 35 publications

The Effects of Tyramine on Salivary Flow Rate and Protein Secretion by Rat Submandibular Glands

The Effects of Tyramine on Salivary Flow Rate and Protein Secretion by Rat Submandibular Glands

The Effect of Chronic Clonidine Administration on Salivary Glands and Caries in the Rat

Abnormally High Levels of Cystatin S in Submandibular Glands, Saliva, and Gingiva of Plaque-resistant Rats

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