Cell apoptosis and proliferation in salivary glands of Sjögren's syndrome.

BACKGROUND: Sjögren's syndrome (SS) occurs associated with parotid neoplasm, non-Hodgkin's B-cell lymphoma, which could impair the condition or be life-threatening for patients. The aim of this work was to analyze cell proliferation and apoptosis modifications in acinar, ductal and inflammatory infiltrate in salivary glands (SG) in patients with Sjögren Syndrome, keratoconjunctivitis, or stomatitis sicca or in healthy subjects, to establish parameters that indicate the likelihood of malignancy of the disease in populations at risk. METHODS: A study was performed with n = 58 histological samples of lower lip SG from patients diagnosed with SS, keratoconjunctivitis, or stomatitis sicca (SICCA) and from healthy subjects (C). Ki67 and caspase-3 immunolabeling were performed. RESULTS: The most important result was significant differences between the three study groups in Ki67 and caspase-3 markers (P < 0.0001) in infiltrated lymphocytes. CONCLUSION: The results of this work are indicative of a high degree of proliferation (85%) in infiltrated lymphocytes (IL) associated with SS which, according the literature, could be considered a risk. Furthermore, the markers used in this work are widely known and represent a lower cost than others and can be used to determine risk groups within the population of SS patients, enabling their follow-up.

Restricted diet modifies carbohydrate metabolism in immature rats.

The aim of the present work was to study the effect of a restricted diet on carbohydrate metabolism in submandibular glands of female prepuber rats and the influence of arachidonic acid derivatives. Rats of 21 days of age were divided into three groups. Group I: normally fed rats. Group II: restricted diet (50% of the normal food intake). Group III: normally restricted diet with re-feeding. The baseline concentration of tissue glycogen was significantly higher in Group II than in I or III and after 60 min of incubation in a glucose free medium all groups showed a glycogen drop. In addition, the glucose metabolism was increased in Group II. Cycloxigenase inhibitors failed to alter (14)CO(2) levels in Groups I and III. In Group II, indomethacin and acetylsalicylic acid inhibited glucose metabolism, which was reverted by PGE(2) addition. The exogenous arachidonic acid metabolism and different eicosanoids showed that restricted diet significantly increased the production of PGE(2) but diminished PGF(2)(alpha) production. Our results suggest that a restricted diet would lead to a new dynamic equilibrium of glucose homeostasis. Prostaglandins E(2) and F(2)(alpha) would participate by adapting the source of energy to tissue demands while maintaining the metabolic features that characterize puberty.

Effect of a restricted diet on the metabolism of glucose in uteri isolated from immature rats: influence of indomethacin and nordihydroguaiaretic acid.

In immature female rats (21 days), a restricted diet (50% of the daily normal intake for 25 days) interrupts sexual development, leaving animals in a state of sexual immaturity. Food restriction does not affect the use of glycogen in uteri isolated and increases 14CO2 production from U14C-glucose in relation to animals receiving normal feeding that reach sexual maturity. Indomethacin and acetylsalicylic acid stop the increase of glucose metabolism produced by underfeeding, without affecting the uteri of rats receiving normal feeding. The addition of PGE2 and PGF2alpha changes the inhibitory effect of indomethacin. Nordihydroguaiaretic acid produces the opposite effect, increasing glucose metabolism only in uteri isolated from immature animals. These results show that immature animals have a higher glucose metabolism if compared to mature rats. The restricted diet, which slows down sexual maturity, keeps this parameter high due to the influence of some eicosanoids.

Effect of fasting on the contractile activity and metabolism of labelled glucose and arachidonic acid in uteri isolated from intact and ovariectomized rat.

The effects of fasting for 4 days on the isometric developed tension (IDT) and on the metabolism of labelled glucose and arachidonic acid in uteri from intact and spayed (25 days) rats, were explored. Starvation produces a fall in the contractile activity of intact rats, while in ovariectomized ones, no differences can be seen with respect to their controls. Fasting produces a fall in the glucose metabolism of both intact and ovariectomized rats, being more noticeable in the former group. Indomethacin (5 x 10(-6) M) increases the metabolism of labelled glucose in all experimental groups, significantly. The metabolism of exogenous arachidonic acid into different eicosanoids, PGE2, PGF2 alpha, 6-keto-F1 alpha and TXB2, shows that total food deprivation diminishes significantly the production of PGE2 in intact rats. In contrast, in ovariectomized starved rats, PGE2 increases markedly. The rest of the metabolites studied are not influenced by fasting. These results show that the effects of fasting on the contractile activity and on the release of some metabolites from arachidonic acid by the uteri isolated from intact rats are not seen in ovariectomized animals.

Functional and proteomic analysis of submandibular saliva in rats exposed to chronic stress by immobilization or constant light.

OBJECTIVE: In this study, we have evaluated the effects of stress on functional and proteomic changes in submandibular saliva of rats. DESIGN: Male adult rats were divided in three groups: IMO (2 h/day of immobilization for 7 days), LL (constant light during 20 days), C (unstressed controls submitted to 14 h light-10h dark cycle). Body weight, food intake and the dry weight of submandibular gland were recorded. Saliva samples, collected under anaesthesia following i.p. administration of isoproterenol and pilocarpine (5 mg/kg), were assayed for total proteins (TP), amylase activity and SDS-PAGE electrophoresis. RESULTS: Body weight, food intake and the dry weight of submandibular gland of IMO rats were lower than those of C and LL groups. The salivary volumes secreted in IMO and LL rats, were significantly higher than in controls. The TP output (µg protein/µg saliva/mg of dry tissue) and amylase activity output (AU/µg of saliva/mg of dry tissue) in IMO were significantly higher than in C and LL animals. The electrophoretic pattern of saliva proteins of LL rats, revealed the absence of a protein band of approximately 25 kDa. This band was composed by the common salivary protein-1 and a prolactin-induced protein as identified by peptide mass fingerprinting. CONCLUSIONS: Differences in body weight and food intake between IMO and LL might be attributed to the sort and intensity of stressors stimuli. The changes in the volume of secreted saliva could be a compensatory mechanism in response to stressors. The increase of total protein in IMO rats and the absence of 25 kDa proteins in LL, would suggest that the submandibular glands respond to the sympathetic nervous system stimuli induced by the stress with an increase of activity of the sympathetic nerves in IMO and a reduction in LL rats.

Correlación de hallazgos serológicos y compuestos orgánicos en saliva en el Síndrome de Sjõgren / Correlation of serological findings and saliva’s organic compounds in Sjõgren’s Syndrome

Introducción: El objetivo del presente trabajo es evaluar los cambios en flujo y composición orgánica en saliva, así como la presencia de anticuerpos anti Ro/SSA y La/SSB séricos y salivales y su implicancia en el diagnóstico no invasivo del SS. Diseño del estudio: Estudio de corte transversal, de 73 pacientes distribuidos en los siguientes grupos experimentales: Síndrome de Sjõgren primario (SSp) (n = 15), SS secundario (SSs) (n = 17), boca seca y ojo seco sin Síndrome de Sjõgren (BO) (n = 20), y controles sanos (C) (n = 21). Se realizó una determinación del flujosalivalbasal y una toma de muestras de saliva para la medición de proteínas totales, IgA, urea y anticuerpos. Se determinaron anticuerpos anti Ro/SSA y La/SSB en muestras de suero y saliva. Resultados: El flujo salival en SSp, SSs, BO fue significativamente menor (p < 0,001) comparado con C. La composición salival de SS mostró modificaciones de componentes estudiados. Los anticuerpos anti Ro/SSA y anti La/SSB aparecieron con mayor frecuencia en suero y saliva en pacientes con SS en comparación con BO y C, siendo la frecuencia de positividad superior en suero en comparación con saliva. Conclusión: La determinación de anticuerpos Ro/SSA en saliva podrían ayudar a diagnosticar a pacientes con xerostomía como el Síndrome de Sjõgren.

Introduction: The aim of this study was to evaluate changes in flow andorganic composition in saliva, the presence of anti Ro/SSA and La/SSBantibodies in serum and saliva and its implication in the noninvasivediagnosis of SS.Study Design: Cross sectional study, 73 patients divided into four experimentalgroups: Primary Sjögren's syndrome (pSS) (n = 15), secondarySS (sSS) (n = 17), dry eye and dry mouth syndrome without Sjögren's(DEMS) (n = 20) and healthy controls (C) (n = 21). We performed a determinationof basal salivary flow and saliva sampling for measurement oftotal protein, IgA, urea and antibodies. We determined anti Ro/SSA andLa/SSB in serum and saliva.Results: The salivary flow in pSS, sSS, DEMS patients was significantlylower (p <0.001) compared with C. The composition of SS salivary componentsstudied showed changes. The anti Ro/SSA and anti La/SSB occurredmore frequently in serum and saliva in SS patients comparedwith DEMS and C, the frecuency of positivity was higher in serum thanin saliva.Conclusion: The determination in saliva of antibodies Ro/SSA may helpdiagnose patients with xerostomy as Sjögren's Syndrome.

Endogenous signalling system involved in parotid gland adenosine A(1) receptor-amylase release.

AIM: In this study, we have determined signalling pathways involved in adenosine A(1) receptor (A(1) receptor)-dependent stimulation of amylase release in rat parotid gland. METHODS: Amylase release, binding and cyclic adenosine monophosphate (cAMP) assays, inositol phosphates (IPs) production and nitric oxide synthase (NOS) activity in the presence of cyclopentyl-1,3-dipropylxanthine (CPA) alone or in the presence of different inhibitory drugs were performed. RESULTS: The binding parameters of specific A(1) antagonist [(3)H]-cyclopentyl 1,3-dipropilxanthine ([(3)H]-DPCPX) in parotid gland membranes show a population of high affinity sites with K(d) (nm) 0.53 +/- 0.06 and B(max) (fmol mg(-1) protein) 122.6 +/- 10.2. CPA stimulation of A(1) receptor exerts an increase in amylase release, IPs accumulation, cAMP production and NOS activity. All these A(1) agonist effects were blocked by the A(1) receptor antagonist DPCPX. Inhibitors of phospholipase C (PLC), calcium/calmodulin (CaM), protein kinase C (PKC), and adenylate cyclase, but not NOS, activities attenuated the CPA stimulatory effect on amylase release. The effect of CPA on amylase release significantly correlated with its action either on cAMP or on IPs accumulation. CONCLUSION: These results suggest that CPA activation of parotid gland A(1) receptor induces a stimulatory effect on amylase release associated with increased production of cAMP and IPs accumulation. The mechanism appears to occur secondarily to stimulation of phosphoinositide turnover via PLC activation. This, in turn, triggers cascade reactions involving CaM and PKC. The CPA stimulation of NOS does not appear to participate in amylase release.

Neurochemical mechanisms of memory control.

Modulation of memory trace retrieval in emotiogenic brain structures, cortex and brainstem reticular formation by postsynaptic noradrenergic and dopaminergic drugs was found. At the initial stage of latent inhibition-a most significant mechanism of information selection-memory trace retrieval is retarded in all structures and in the cortex and the zona incerta later on. A haloperidol model of latent inhibition was obtained. Most important role of dopaminergic system in latent inhibition was shown. Inhibition of the GABA-benzodiazepine-ionophore complex by the blockade of GABA-receptors induced by bicuculline, the chloride channels by picrotoxin, the benzodiazepine receptors by flumazenil (R015-1788) and R015-3505 facilitates the memory trace retrieval damaged by amnesic agent. The dopaminergic activation enhances the dominant state and developes conditions for switching on the interferential GABA-ergic inhibition.

Effects of a restricted diet on in vitro spontaneous activity and glucose metabolism in isolated rat uterus. Influence of castration.

The effects of a restricted-diet (50% of the normal intake during 25 d) on the isometric developed tension (IDT), the metabolism of labelled glucose, and the levels of glycogen, of uteri isolated from ovariectomized (25 d) and non-ovariectomized rats were explored. The restriction of food intake produced a fall in the contractile activity of normal, non-ovariectomized, rats in permanent diestrous compared to normally fed rats in diestrous. On the contrary, in castrated rats, the IDT of isolated uterus from underfed rats, was significantly higher than its normal-fed controls. In normal rats the formation of 14CO2 from U 14C-glucose was significantly lower in uterine preparations from restricted-diet animals than the control one. On the other hand, in castrated rats, the formation of 14CO2 increased as a result of underfeeding. The post-incubation levels of glycogen in uteri from normal-fed animals diminished significantly in comparison to 0 time values. In uteri from rats subjected to a dietary restriction, the initial glycogen values were lower than in normal-fed controls, but they did not decline further after incubation in KRB medium. On the contrary, even when the levels of glycogen were significantly lower at 0 time than in diestrous animals, they diminished in ovariectomized rats after incubation, no matter the diet. The above results indicate that the effects of restricted-diet on contractile activity, levels of glycogen and glucose metabolism were not observed in ovariectomized rats. Further researches are needed to clarify that point.