Enhancing quantitative approaches for assessing community resilience.

Scholars from many different intellectual disciplines have attempted to measure, estimate, or quantify resilience. However, there is growing concern that lack of clarity on the operationalization of the concept will limit its application. In this paper, we discuss the theory, research development and quantitative approaches in ecological and community resilience. Upon noting the lack of methods that quantify the complexities of the linked human and natural aspects of community resilience, we identify several promising approaches within the ecological resilience tradition that may be useful in filling these gaps. Further, we discuss the challenges for consolidating these approaches into a more integrated perspective for managing social-ecological systems.

Concurrent palliative chemoradiation leads to survival and quality of life benefits in poor prognosis stage III non-small-cell lung cancer: a randomised trial by the Norwegian Lung Cancer Study Group.

BACKGROUND: The palliative role of chemoradiation in the treatment of patients with locally advanced, inoperable non-small-cell lung cancer stage III and negative prognostic factors remains unresolved. METHODS: Patients not eligible for curative radiotherapy were randomised to receive either chemoradiation or chemotherapy alone. Four courses of intravenous carboplatin on day 1 and oral vinorelbin on days 1 and 8 were given with 3-week intervals. Patients in the chemoradiation arm also received radiotherapy with fractionation 42 Gy/15, starting at the second chemotherapy course. The primary end point was overall survival; secondary end points were health-related quality of life (HRQOL) and toxicity. RESULTS: Enrolment was terminated due to slow accrual after 191 patients from 25 Norwegian hospitals were randomised. Median age was 67 years and 21% had PS 2. In the chemotherapy versus the chemoradiation arm, the median overall survival was 9.7 and 12.6 months, respectively (P<0.01). One-year survival was 34.0% and 53.2% (P<0.01). Following a minor decline during treatment, HRQOL remained unchanged in the chemoradiation arm. The patients in the chemotherapy arm reported gradual deterioration during the subsequent months. In the chemoradiation arm, there were more hospital admissions related to side effects (P<0.05). CONCLUSION: Chemoradiation was superior to chemotherapy alone with respect to survival and HRQoL at the expense of more hospital admissions due to toxicity.

Vinorelbine and gemcitabine vs vinorelbine and carboplatin as first-line treatment of advanced NSCLC. A phase III randomised controlled trial by the Norwegian Lung Cancer Study Group.

BACKGROUND: Platinum-based doublet chemotherapy is the standard first-line treatment for advanced non-small cell lung cancer (NSCLC), but earlier studies have suggested that non-platinum combinations are equally effective and better tolerated. We conducted a national, randomised study to compare a non-platinum with a platinum combination. METHODS: Eligible patients had stage IIIB/IV NSCLC and performance status (PS) 0-2. Patients received up to three cycles of vinorelbine 60 mg m(-2) p.o.+gemcitabine 1000 mg m(-2) i.v. day 1 and 8 (VG) or vinorelbine 60 mg m(-2) p.o. day 1 and 8+carboplatin area under the curve=5 (Calvert's formula) i.v. day 1 (VC). Patients ≥75 years received 75% of the dose. Endpoints were overall survival, health-related quality of life (HRQoL), toxicity, and the use of radiotherapy. RESULTS: We randomised 444 patients from September 2007 to April 2009. The median age was 65 years, 58% were men and 25% had PS 2. Median survival was VG: 6.3 months; VC: 7.0 months, P=0.802. Vinorelbine plus carboplatin patients had more grade III/IV nausea/vomiting (VG: 4%, VC: 12%, P=0.008) and grade IV neutropenia (VG: 7%, VC: 19%, P<0.001). Infections, HRQoL and the use of radiotherapy did not differ significantly between the treatment groups. CONCLUSION: The two regimens yielded similar overall survival. The VG combination had only a slightly better toxicity profile.

Astroblastoma - a case report of a rare neuroepithelial tumor with complete remission after chemotherapy.

INTRODUCTION: Astroblastoma is a rare glial tumor of uncertain origin affecting mostly children, adolescents and young adults. Given the rarity and the definitional problems concerning this tumor entity, the prognosis and appropriate treatment are at this point unclear. CASE REPORT: A 50-yearold Caucasian female presented with a seizure. Radiological findings showed a welldefined circumscribed tumor located in the right cerebral frontal lobe. The patient underwent primary surgery followed by postoperative radiotherapy. After 6 months the tumor recurred with multiple small lesions not available for surgery. Chemotherapy was administered with complete radiological response. Seven years after surgery and more than 6 years after completed chemotherapy the patient is free of disease. Histopathology revealed a gliomatous tumor with gemistocyte-like tumor cells arranged in palisades or strings and areas with perivascular pseudorosettes, consistent with astroblastoma. Immunophenotype and ultrastructural findings confirmed the diagnosis and verified the neuroepithelial origin. CONCLUSION: Astroblastomas are rare brain tumors and pose a challenge in the diagnostic and clinical approach. In general, they have an unpredictable course with a tendency of recurrence. This and other case reports support a survival benefit of chemotherapy, suggesting this as an important treatment option for these patients.

The non-proteolytic house dust mite allergen Der p 2 induce NF-kappaB and MAPK dependent activation of bronchial epithelial cells.

BACKGROUND: House dust mites (HDM) are well-known as a source of indoor aeroallergens and for causing allergic airway diseases. Some proteolytic HDM allergens are known to activate respiratory epithelial cells to produce pro-inflammatory mediators, while there is limited knowledge regarding such activity among non-proteolytic HDM allergens. OBJECTIVE: To investigate whether Der p 2, a major non-proteolytic allergen of Dermatophagoides pteronyssinus, activates respiratory epithelial cells to produce mediators involved in asthma pathogenesis and to elucidate the mechanism of such activation. METHODS: The human bronchial epithelial cell line BEAS-2B, normal human bronchial epithelial (NHBE) cells and the alveolar epithelial cell line A549 were exposed to recombinant Der p 2. Following exposure, we analysed a panel of soluble mediators and cell adhesion receptors involved in asthma pathogenesis by promoting recruitment, survival and binding of inflammatory cells. The involvement of nuclear factor (NF)-kappaB and mitogen-activated protein kinases (MAPKs) was studied using specific inhibitors. RESULTS: Der p 2 activated bronchial BEAS-2B and NHBE cells, but not alveolar A549 cells. In BEAS-2B cells Der p 2 induced dose-dependent up-regulation in both mRNA level and protein secretion of granulocyte-macrophage colony-stimulating factor, IL-6, IL-8, monocyte-chemotactic protein-1 and macrophage inflammatory protein-3alpha. Secretion as well as surface expression of intercellular adhesion molecule (ICAM)-1 was also up-regulated, which was associated with increased adhesion of monocytes to the epithelial cells. The release of cytokines and chemokines was regulated by NF-kappaB and MAPK activation in different ways, while expression of ICAM-1 was solely dependent on NF-kappaB activation. CONCLUSION: These results show that Der p 2 activates respiratory epithelial cells, indicating that this non-proteolytic allergen, in addition to its immunogenic properties, can aggravate respiratory airway disease by adjuvant-like activation of the lung epithelium.

Photodynamic therapy with 5-aminolaevulinic acid, dimethylsulfoxide and curettage in basal cell carcinoma: a 6-year clinical and histological follow-up.

BACKGROUND: Long-term follow-up data are needed to evaluate treatment effect after photodynamic therapy (PDT). OBJECTIVE: To investigate long-term clinical, histological and cosmetic follow-up results in basal cell carcinoma (BCC) after PDT, including treatment response related to patients and lesion characteristics. MATERIALS AND METHODS: A longitudinal study of 44 patients with 60 histologically verified BCC tumours, treated with one or two sessions of dimethylsulfoxide (DMSO)-supported 5-aminolaevulinic acid--PDT following curettage, was performed. Lesions in complete remission after 3 months were followed with clinical inspection, histological investigation and evaluation of cosmetic outcome at regular intervals; long-term efficacy assessed as verified recurrence within 72 months after PDT. RESULTS: Complete remission at 3 months was achieved in 55 lesions from 39 patients. Two patients with one lesion each died. At 72 months, 43 of 53 lesions remained disease-free (81%); 68% remained after one treatment session, and 91% remained after two treatment sessions. Recurrence of tumour occurred at 6, 12, 24 and 36 months in 2, 4, 2 and 2 lesions, respectively; clinical investigation identified 97% of them. Male sex and H-mid-face zone were significantly associated with recurrence. The cosmetic outcome at 72 months was rated as good or excellent by patients and investigators in more than 90% of evaluated cases. CONCLUSION: DMSO-PDT following curettage is an effective treatment for BCC, with favourable long-term clinical, histopathological and cosmetic results. Clinical examination of treated lesions appears to be sufficient for long term follow up.

Adaptive capacity in ecosystems.

Understanding the adaptive capacity of ecosystems to cope with change is crucial to management. However, unclear and often confusing definitions of adaptive capacity make application of this concept difficult. In this paper, we revisit definitions of adaptive capacity and operationalize the concept. We define adaptive capacity as the latent potential of an ecosystem to alter resilience in response to change. We present testable hypotheses to evaluate complementary attributes of adaptive capacity that may help further clarify the components and relevance of the concept. Adaptive sampling, inference and modeling can reduce key uncertainties incrementally over time and increase learning about adaptive capacity. Such improvements are needed because uncertainty about global change and its effect on the capacity of ecosystems to adapt to social and ecological change is high.

Effectiveness of third-generation chemotherapy on the survival of patients with advanced non-small cell lung cancer in Norway: a national study.

BACKGROUND: To investigate whether the introduction of modern third-generation chemotherapy was associated with survival benefits in a national population of patients with advanced non-small cell lung cancer (ANSCLC) and to explore geographical and temporary variations in the utilisation of chemotherapy. METHODS: All patients with ANSCLC in the Cancer Registry of Norway during 1994-2005 were included. Using sales of vinorelbine as an indicator for chemotherapy, annual county utilisation rates were calculated. Survival before and after the general introduction of vinorelbine and associations between survival and variations in utilisation in counties were investigated. In a subgroup, the predictors of having received chemotherapy were explored. RESULTS: Of 24 875 registered patients with lung cancer, 13 757 had ANSCLC. The annual utilisation of the indicator drug in Norway increased from 3.7 to 184.2 g (1998-2005). Median survival increased from 149 to176 days (p<0.001). The adjusted hazard ratio (HR) for a diagnosis after the introduction was 0.93 (95% CI 0.88 to 0.99). County utilisation rates of vinorelbine (increments of 100 mg/1000 inhabitants) were inversely associated with the risk of death (HR 0.84, 95% CI 0.73 to 0.98). County of residence predicted chemotherapy utilisation with odds ratios in the range 0.13 (95% CI 0.1 to 0.19) to 1.04 (95% CI 0.64 to 1.69), a county with traditionally high utilisation as reference. CONCLUSION: Utilisation of third-generation chemotherapy was associated with slightly increased survival of patients with ANSCLC. Geographical and temporal differences in utilisation indicate variable quality of delivered care.

The hsp90 chaperone complex regulates intracellular localization of the dioxin receptor.

The molecular chaperone complex hsp90-p23 interacts with the dioxin receptor, a ligand-dependent basic helix-loop-helix (bHLH)/Per-Arnt-Sim domain transcription factor. Whereas biochemical and genetic evidence indicates that hsp90 is important for maintenance of a high-affinity ligand binding conformation of the dioxin receptor, the role of hsp90-associated proteins in regulation of the dioxin receptor function remains unclear. Here we demonstrate that the integrity of the hsp90 complex characterized by the presence of the hsp90-associated cochaperone p23 and additional cochaperone proteins is important for regulation of the intracellular localization of the dioxin receptor by two mechanisms. First, in the absence of ligand, the dioxin receptor-hsp90 complex was associated with the immunophilin-like protein XAP2 to mediate cytoplasmic retention of the dioxin receptor. Second, upon exposure to ligand, the p23-associated hsp90 complex mediated interaction of the dioxin receptor with the nuclear import receptor protein pendulin and subsequent nuclear translocation of the receptor. Interestingly, these two modes of regulation target two distinct functional domains of the dioxin receptor. Whereas the nuclear localization signal-containing and hsp90-interacting bHLH domain of the receptor regulates ligand-dependent nuclear import, the interaction of the p23-hsp90-XAP2 complex with the ligand binding domain of the dioxin receptor was essential to mediate cytoplasmic retention of the ligand-free receptor form. In conclusion, these data suggest a novel role of the hsp90 molecular chaperone complex in regulation of the intracellular localization of the dioxin receptor.

Estrogen regulation of placental alkaline phosphatase gene expression in a human endometrial adenocarcinoma cell line.

A human endometrial tumor (Ishikawa) cell line in culture responded to estradiol stimulation, as measured by growth and alkaline phosphatase activity. These effects were similar whether the medium was enriched with serum or was serum-free. Estradiol increased placental alkaline phosphatase activity 2-3-fold over control in these Ishikawa cells. The mechanism for this increase appeared to be at the level of transcription, at least in part, since there was an increase in the concentration of placental alkaline phosphatase mRNA. The administration of tamoxifen or 4-hydroxytamoxifen was unable to antagonize the estradiol-stimulated alkaline phosphatase enzyme activity or mRNA expression. The administration of tamoxifen alone had no effect on alkaline phosphatase enzyme activity, but tamoxifen did stimulate the steady state concentration of alkaline phosphatase mRNA. In contrast, a new antiestrogen, ICI 164,384, was able to antagonize both of these estradiol-stimulated effects.

Mitosin and pHH3 predict poorer survival in astrocytomas WHO grades II and III.

AIMS: The limitations of the current WHO classification of astrocytomas call for a sustained effort to improve diagnostic and prognostic accuracy. The relationship between tumour growth and clinical outcome suggests that proliferative activity should be examined. The objective of this study was to evaluate the diagnostic and prognostic value of the proliferation markers mitosin and phosphohistone H3 (pHH3) in infiltrative astrocytomas WHO grades II and III and compare the findings with mitotic count and Ki-67/MiB-1 immunostaining. METHODS: Fifty-nine and thirty-three infiltrative astrocytomas WHO grades II and III, respectively, were immunostained with the proliferation markers mitosin and pHH3 using standard immunohistochemical procedures. The expression was quantified as a proliferative index (PI) and statistically evaluated with Spearman's rank correlation test, Wilcoxon-Mann-Whitney U test, and univariable and multivariable COX regression survival analyses. RESULTS: Significant positive correlations were found between these proliferation markers. The number of mitoses, pHH3 mitotic figures (MFs), the Ki-67/MiB-1 PI and the mitosin PI were greater in WHOgrade III anaplastic astrocytomas compared to WHO grade II diffuse astrocytomas, while pHH3 PI only showed a trend. All proliferation markers were associated with poorer prognosis, but mitotic count was not. Ki-67/MiB-1, mitosin and pHH3 MF achieved statistical significance in the univariable analyses of both time to relapse (TTR) and overall survival (OS). Only mitosin remained significant in both multivariable analyses. pHH3 was significant in the multivariable analysis of OS but not of TTR. Clinical factors including age, extent of surgical resection and WHO performance status were also significantly correlated with survival. CONCLUSIONS: In conclusion, mitosin and pHH3 immunostaining have prognostic and diagnostic value in the clinical assessment of patients with infiltrative astrocytomas. The inclusion of proliferation markers in a layered diagnosis should be considered in the upcoming revision of the WHO classification system.

Interferon inhibits preferentially the synthesis of proteins associated with growth stimulation of Swiss 3T3 mouse fibroblasts.

The putative role of inhibition of protein synthesis within the antiproliferative effect of interferon was analyzed in serum-stimulated Swiss 3T3 mouse fibroblasts. We observed an apparent coupling between protein-synthesis inhibition during G1 and a delayed entry into the S-phase. To reveal any specificity in the protein-synthesis inhibition, we measured the amounts of synthesis of 56 major individual proteins, by using isotope double-labelling and two-dimensional gel electrophoresis. Interferon inhibited preferentially the synthesis of proteins which were increased after serum stimulation, whereas proteins synthesized in constant or decreased amounts after serum stimulation were significantly more resistant. The effects of interferon were also compared to those of 5,6-dichloro-1-beta-ribofuranosylbenzimidazole (DRB), an inhibitor of transcription. All interferon-sensitive proteins studied were inhibited by DRB treatment, but in addition DRB also inhibited several proteins which were completely resistant to interferon. We conclude that interferon primarily inhibits protein synthesis originating from a subset of newly transcribed messenger RNAs. The mechanism(s) for inhibition of protein synthesis and the possible relationship to the antiproliferative and antiviral effects of interferon are discussed.

Multicenter phase II trial of paclitaxel, cisplatin, and etoposide with concurrent radiation for limited-stage small-cell lung cancer.

PURPOSE: To investigate the feasibility, efficacy, and safety of adding paclitaxel to cisplatin/etoposide chemotherapy and concurrent thoracic radiotherapy (TRT) in treatment of limited-stage small-cell lung cancer (LD-SCLC). PATIENTS AND METHODS: Patients received five courses of chemotherapy (paclitaxel 175 mg/m2 1-hour intravenous [IV] infusion day 1; cisplatin 50 mg/m(2) IV day 1; etoposide 100 mg/m2 IV day 1; oral etoposide 100 mg bid days 2 to 5) at 3-week intervals. TRT (42 Gy administered in 15 fractions) was administered concurrent with chemotherapy cycle 3. All patients were evaluated before starting TRT and 4 weeks after termination of chemotherapy. Patients achieving complete remission (CR) were administered prophylactic cranial irradiation. RESULTS: Thirty-nine patients were included, and the median age was 63 years. The median follow-up was 36 months (range, 19 to 57 months). The overall response rate was 92% (CR, 81%; partial response, 11%), and the median survival was 21 months. The 1- and 2-year disease-specific survival rates were 69% and 37%, respectively. Of 29 CR patients, 83% have relapsed. Brain metastasis was as frequent as local recurrences (42%). Hematologic toxicity included grade 3 to 4 leukopenia in 74% of patients and grade 3 thrombocytopenia in 10%. One treatment-related death occurred as a result of severe neutropenia and septicemia. Hematotoxicity caused dose reductions in 31% of courses. One patient had an anaphylactic reaction during the first paclitaxel infusion. Paclitaxel-related neuropathy and myalgia were reversible. Grade 3 esophagitis was seen in five patients during and shortly after TRT. CONCLUSION: This novel multimodal regimen is effective and well tolerated in patients with LD-SCLC. It compares favorably with previously published phase II studies.

Differential expression of estrogen-regulated CD4 and Ia positive cells in the immature rat uterus.

Estradiol treatment of sexually immature Sprague-Dawley, Cr:NIH-nu/+ and Cr:NIH-nu/nu rats for 2 days results in a significant increase in the number of uterine eosinophils and OX-42 positive macrophages. However, only Sprague-Dawley rats exhibit an estrogen regulated increase in the number of cells expressing immunoreactive CD4 and Ia, suggesting that the differential responsiveness to the effects of estradiol between the two strains of rats may be genetically controlled. Nevertheless, Cr:NIH-nu/nu rats, which are deficient in T-cells, possess virtually identical numbers of CD4 positive staining uterine cells as compared to their nu/+ littermate controls, indicating that the expression of immunoreactive CD4 is associated with a resident non-T-cell population. In addition, a message for rat CD4 was observed in Northern blots of uterine mRNA, suggesting that the immunoreactive CD4 expressed by uterine cells is probably a fully functional cell surface antigen/receptor rather than a truncated form which only expresses the antigenic determinant recognized by the W3/25 monoclonal antibody.

Prognostic significance of Ki-67/MIB-1 proliferation index in meningiomas.

Even though tumor grade, subtype, and extent of resection are strong prognostic factors in human meningiomas, the growth of this tumor is still unpredictable, and additional prognostic markers are needed. Thus, immunohistochemical determination of proliferative activity using the Ki-67 equivalent antibody MIB-1 has gained increased attention. However, the reported prognostic significance of this marker in meningiomas is not fully clarified. The aim of this study was to investigate the prognostic role of MIB-1 proliferation index (PI) in a series of meningiomas comprising 23 benign, 17 atypical, and 9 anaplastic tumors. MIB- 1 PI increased with increasing tumor grade and discriminated significantly benign from atypical and anaplastic meningiomas whereas no difference was found between the latter two grades. However, due to the considerable overlap of PI values between the various grades, one should be circumspect before using this criterion for tumor grading. Furthermore, MIB-1 PIs were significantly higher in recurrent tumors compared with non-recurrent and a reliable MIB-1 PI cut-off value of 10% was established. This value, however, cannot automatically be adapted by other laboratories and must be regarded just as a guideline. In conclusion, MIB-1 PI appears as an important prognostic factor and should be used in combination with traditional histological criteria for malignancy in order to identify meningiomas with increased risk of recurrence.

The stimulation of uterine complement component C3 gene expression by antiestrogens.

We have previously demonstrated that complement component C3 is regulated by estradiol in the rat uterus. The antiestrogens tamoxifen, LY117018, and LY156758 exert both agonist and antagonist effects on the immature rat uterus. In this study, these three antiestrogens also stimulated an increase in the synthesis and secretion of C3. The combination of LY117018 and estradiol did not increase C3 to a greater extent than LY117018 alone, which suggests a similar mechanism of regulation. The regulation may be transcriptional since both estradiol and tamoxifen increase the concentration of C3 mRNA. Results of in situ hybridization revealed that the increase in C3 mRNA occurred in the luminal epithelial cells. Although the induction by estradiol and the antiestrogens was similar in most aspects, the time course for tamoxifen-stimulated synthesis differed from estradiol in that the time required to achieve maximal concentrations of C3 was delayed by 12 h with tamoxifen. This pattern did not appear to be related to the time it took to convert tamoxifen to 4-hydroxytamoxifen since the C3 response for these antiestrogens were identical. The antiestrogen-stimulated increase in C3 synthesis and mRNA concentration was prevented by the co-administration of progesterone lending support to the hypothesis that the antiestrogens regulate C3 synthesis via a mechanism similar to estrogen.

The use of non-proven therapy among patients treated in Norwegian oncological departments. A cross-sectional national multicentre study.

A national multicentre study was performed to investigate the prevalent use of "alternative medicine", here called "non-proven therapies (NPT)", applied among Norwegian cancer patients. Of 911 patients invited to take part in the study, 642 were included in the analysis. Demographic characteristics were collected for all patients. The participating physicians gave information about the patients' clinical characteristics. Among 630 evaluable patients, 20% had been or were present users of NPTs for their oncological disease. The preferred methods were healing by hand and faith healing. Herbs, vitamins, diets and Iscador were other popular methods. As many as 40% of the users of NPTs had used NPTs earlier for non-malignant diseases. Elderly patients were less likely to use NPTs. Use was high in the northern part of Norway.

Effect of 17 alpha-ethynylestradiol on the induction of cytochrome P-450 by 3-methylcholanthrene in cultured chick embryo hepatocytes.

This study investigated the effects of estrogens on the induction of cytochrome P-450 by polycyclic aromatic hydrocarbons in primary cultures of chick embryo hepatocytes. Exposure to polycyclic aromatic hydrocarbons, such as 3-methylcholanthrene led to 2- to 3-fold increases of cytochrome P-450. The amount of cytochrome P-450 induced by 3-methylcholanthrene was increased 40-50% when the synthetic estrogen, 17 alpha-ethynylestradiol, was also present. The rate of decay of cytochrome P-450 in the presence of cycloheximide as measured spectrophotometrically was similar in cells previously treated with either 3-methylcholanthrene or 3-methylcholanthrene plus 17 alpha-ethynylestradiol, suggesting that 17 alpha-ethynylestradiol did not affect the stability of the 3-methylcholanthrene-induced cytochrome P-450. In contrast, 17 alpha-ethynylestradiol did not potentiate the induction of cytochrome P-450 by phenobarbital-like inducers, such as 2-propyl-2-isopropylacetamide, as indicated by a lack of increase in both the content of cytochrome P-450 and benzphetamine demethylase activity. The naturally occurring estrogens, 17 beta-estradiol and estrone, and the synthetic estrogen, diethylstilbestrol, did not affect cytochrome P-450 induction by 3-methylcholanthrene, suggesting that the effect of 17 alpha-ethynylestradiol was not mediated via the estrogen receptor. We investigated whether the amount of cytochrome P-450 increased in the presence of 17 alpha-ethynylestradiol was the same or different from that induced by 3-methylcholanthrene. Treatment with 17 alpha-ethynylestradiol alone resulted in a small increase in ethoxyresorufin deethylase activity. The enzymatic activities of 7-ethoxyresorufin and aryl hydrocarbon hydroxylase, when expressed per cytochrome P-450 content, were identical in microsomes from cells treated with either 3-methylcholanthrene or the combination of 3-methylcholanthrene and 17 alpha-ethynylestradiol. The data suggest that the additional cytochrome P-450 induced by the combination of 17 alpha-ethynylestradiol and 3-methylcholanthrene was the same isozyme as that induced by 3-methylcholanthrene alone.

Dopamine increases potassium efflux in the rat parotid gland by stimulating noradrenaline release from sympathetic nerve endings.

By studying 86Rb+ efflux (tracer for potassium) and labelled NA ([3H]NA) efflux from preloaded parotid glands in vitro it is suggested that dopamine stimulates potassium efflux through an indirect sympathomimetic activity--i.e. releasing noradrenaline from sympathetic nerve endings.

Differences in dopamine- and noradrenaline-induced amylase release from the rat parotid gland.

The effects of dopamine and noradrenaline on amylase secretion from rat parotid gland were studied in a batch incubation system. Dopamine effectively caused amylase secretion but the concentration-response curve was shifted to the right in reserpinized animals, suggesting a minor indirect component in the action of dopamine. The noradrenaline-evoked secretion was the same in reserpinized glands as in the controls. Bromocriptine, a dopamine receptor agonist, was without effect on amylase secretion. The dopamine receptor antagonists pimozide, chlorpromazine, haloperidol and droperidol as well as SKF 38393 all effectively inhibited dopamine-induced amylase secretion without affecting the enzyme release caused by noradrenaline. The D-2 antagonist sulpiride was without effect on both dopamine- and noradrenaline-stimulated secretion. The dopamine-induced secretion was also significantly blocked by the non-selective beta-blocker propranolol as well as by beta 1- and beta 2-selective antagonists. Several alpha-antagonists were all partial blockers of dopamine-stimulated amylase secretion. In contrast, the noradrenaline-evoked amylase release was exclusively abolished by propranolol and beta 1-selective antagonists. The results suggest that the dopamine- and noradrenaline-induced amylase secretion are activated via different receptor systems, and that dopamine stimulation is mainly a postsynaptic D-1 effect and only to a minor extent due to presynaptic interaction.