Real-world results of ibrutinib in patients with relapsed or refractory chronic lymphocytic leukemia: data from 95 consecutive patients treated in a compassionate use program. A study from the Swedish Chronic Lymphocytic Leukemia Group

Ibrutinib, a Bruton's tyrosine kinase inhibitor is approved for relapsed/refractory and del(17p)/TP53 mutated chronic lymphocytic leukemia. Discrepancies between clinical trials and routine health-care are commonly observed in oncology. Herein we report real-world results for 95 poor prognosis Swedish patients treated with ibrutinib in a compassionate use program. Ninety-five consecutive patients (93 chronic lymphocytic leukemia, 2 small lymphocytic leukemia) were included in the study between May 2014 and May 2015. The median age was 69 years. 63% had del(17p)/TP53 mutation, 65% had Rai stage III/IV, 28% had lymphadenopathy ≥10cm. Patients received ibrutinib 420 mg once daily until progression. At a median follow-up of 10.2 months, the overall response rate was 84% (consistent among subgroups) and 77% remained progression-free. Progression-free survival and overall survival were significantly shorter in patients with del(17p)/TP53 mutation (P=0.017 and P=0.027, log-rank test); no other factor was significant in Cox proportional regression hazards model. Ibrutinib was well tolerated. Hematomas occurred in 46% of patients without any major bleeding. Seven patients had Richter's transformation. This real-world analysis on consecutive chronic lymphocytic leukemia patients from a well-defined geographical region shows the efficacy and safety of ibrutinib to be similar to that of pivotal trials. Yet, del(17p)/TP53 mutation remains a therapeutic challenge. Since not more than half of our patients would have qualified for the pivotal ibrutinib trial (RESONATE), our study emphasizes that real-world results should be carefully considered in future with regards to new agents and new indications in chronic lymphocytic leukemia.

A novel application of multi-wavelength TIRF spectroscopy for real time monitoring of antithrombin interactions with immobilized heparin

Real time interactions of antithrombin (AT) with Corline Heparin Surfaces (CHS) with one and two layers of heparin conjugate have been examined using a multi-wavelength TIRF spectroscopy technique with continuous flow. Fluorescently labeled AT, adsorbed from citrated human blood plasma, showed significantly higher signals on CHS compared to the cationic surface used to attach the heparin conjugate. The AT binding to CHS was very stable, also after exposure to soluble heparin at a concentration of 1.5 IU/mL. Only a few percent of the bound AT were displaced from the surfaces by AT present in plasma after long-term exposure to plasma. In contrast, larger amounts of the freshly added AT had adsorbed to the surfaces, especially to the surface with two layers of heparin conjugate, indicating the presence of unsaturated AT binding sites. The amount of AT bound to the different surfaces was quantified after elution using an enzyme immunoassay (EIA). Characteristic emission spectra of proteins and fluorophores of labeled proteins, obtained at the surfaces after a long-term exposure to plasma, confirmed their presence at the surfaces. The multi-wavelength TIRF technique proved to be a useful tool when combined with other techniques to study the time course of interactions of fluorescently labeled proteins with biomaterials, even in a complex environment such as plasma.

Non-physiological levels of circulating cortisol in growth hormone-treated hypopituitary adults after conventional cortisone substitution

OBJECTIVE

To assess the usefulness of measuring plasma cortisol profiles in growth hormone-treated hypopituitary adults and to compare these with cortisol levels in healthy controls.

METHODS

Eleven ACTH-deficient adult patients received 12.5 mg cortisone-acetate orally at 16.00 h and 25 mg at 07.00 h. The patients arrived in the ward at 12.00 h. After tablet intake at 16.00 h, samples for serum cortisol were taken at hourly intervals for the next 24 h, except between 07.00 and 12.00 h when samples were drawn every half hour; 24-h urinary free cortisol (24-h-UFC) excretion was collected simultaneously. For comparison, 8 healthy controls were investigated.

RESULTS

The patients had circulating cortisol levels with very low plasma cortisol at 07.00 h before their morning dose of cortisone acetate. At the same time period, controls had their highest plasma cortisol levels. After tablet intake the patients had a rapid initial absorption of cortisol, but a marked variability in the morning peak levels (Cmax), and the Cmax was in general higher and occurred 90 min later than the Cmax in the controls. The 24-h-UFC excretion and 24-h area under the curve (24-h-AUC) did not differ between patients and controls. The female patients had higher 24-h-AUC for plasma cortisol (p=0.032) and tended to have higher plasma cortisol peaks in the morning, but had levels of 24-h-UFC similar to those of the male patients.

CONCLUSIONS

Conventional cortisone substitution with a twice-daily replacement regimen in hypopituitary adults results in abnormal circulating cortisol profiles with low or non-measurable morning values and variable individual peaks. This suggests that the present dosing schemes have to be improved and that cortisone substitution should be individualized.

Trofosfamide as salvage therapy for anaplastic large cell lymphoma relapsing after high-dose chemotherapy

Patients with relapsed aggressive lymphoma after high dose chemotherapy have a very poor prognosis and long-term survival is rare. Most patients are not eligible for allogeneic stem cell transplantation in this setting and treatment, therefore, becomes palliative. A few studies have shown that trofosfamide, an oral alkylating agent, may be effective as palliative treatment in non-Hodgkin's lymphoma. Trofosfamide therapy is considered rather non-toxic with an overall response rate from 50 to 80%. Most responses are, however, partial and their duration is short. We report a patient with a very aggressive ALK + anaplastic large cell lymphoma (ALCL), relapsing shortly after high dose chemotherapy. Unrelated allogeneic transplantation was hot possible. After several radio/chemotherapy regimens trofosfamide was started as palliative treatment. This therapy resulted in a complete remission, still ongoing, 27 months after termination of intravenous cytotoxic therapy and 16 months after withdrawal of trofosfamide. Thus, in this particular case, trofosfamide turned out to be an unexpectedly effective salvage therapy for an otherwise very aggressive relapsing ALCL.

Serum from patients with chronic idiopathic thrombocytopenic purpura frequently affect the platelet function

In most, but not all, cases of chronic idiopathic thrombocytopenic purpura (ITP), bleeding complications are known to occur when the platelet count is low. The present study investigates the effect of ITP sera on the in vitro platelet function of donor platelets. Sera from 58 ITP patients were investigated. Using an indirect monoclonal antibody specific immobilisation of platelet antigen (MAIPA) technique, GPIIb/IIIa and GPIb/IX specific antibodies were found in 23 and 20 patients, respectively. Twelve of them had antibodies against both glycoprotein (GP) complexes. The ITP sera's effect on donor platelets was investigated by aggregometry and the results were compared with the ones of 26 healthy donor sera. Grouped together, the ITP sera significantly impaired the ADP-induced platelet aggregation of donor platelets compared to the control sera; the mean relative aggregation response (T(max)) seen for the ITP and control sera were 82 +/- 21% and 92 +/- 7%, respectively (p = 0.0157). However, 6 ITP sera gave an enhanced aggregation response, whereas 17 ITP sera resulted in an impaired platelet aggregation, when using the mean +/- 2 S.D. recorded for the controls as the normal range. There was not any correlation between aggregation response, platelet number or the presence of GPIb/IX or GPIIb/IIIa specific antibodies, other than the fact that all ITP sera causing an enhanced aggregation were from patients with a platelet number less then 100 x 10(9)/l at the time of blood sampling. It is concluded that some ITP sera can either enhance or impair the platelet aggregation response, but in most cases, a normal response is obtained.

Photophysical characterization of natural cis-carotenoids

By means of steady-state fluorescence spectroscopy we explore the photophysics of two lowest lying singlet excited states in two natural 15-cis-carotenoids, namely phytoene and phytofluene, possessing three and five conjugated double bonds (N), respectively. The results are interpreted in relation to the photophysics of all-transcarotenoids with varying N. The fluorescence of phytofluene is more Stokes-shifted relative to that of phytoene, and is ascribed to the forbidden S1-->S0 transition, with its first excited singlet state (S1) lying 3340 cm-1 below the dipole allowed second excited singlet state (S2), at 77 K. For phytoene the S2 and S1 potential surfaces are closer in energy, probably giving rise to the mixed S2 and S1 fluorescence characteristics. The origin of phytoene fluorescence is discussed and is suggested to be due to the S1-->S0 transition; with the S1 state located 1100 cm-1 below S2 at 77 K. The dependence of the fluorescence quantum yield on temperature and viscosity shows that large amplitude molecular motions are involved in the radiationless relaxation process of phytoene. The transition dipole moment of absorption and emission are parallel in phytoene and nonparallel in phytofluene.

Filamentous bacteriophage stability in non-aqueous media

BACKGROUND

Filamentous bacteriophage are used as general cloning vectors as well as phage display vectors in order to study ligand-receptor interactions. Exposure to biphasic chloroform-water interface leads to specific contraction of phage, to non-infective I- or S-forms.

RESULTS

Upon exposure, phage were inactivated (non-infective) at methanol, ethanol and 1-propanol concentrations inversely dependent upon alcohol hydrophobicity. Infectivity loss of phage at certain concentrations of 1-propanol or ethanol coincided with changes in the spectral properties of the f1 virion in ultraviolet fluorescence and circular dichroism studies.

CONCLUSIONS

The alcohols inactivate filamentous phage by a general mechanism--solvation of coat protein--thereby disrupting the capsid in a manner quite different from the previously reported I- and S-forms. The infectivity retention of phagemid pG8H6 in 99% acetonitrile and the relatively high general solvent resistance of the phage strains studied here open up the possibility of employing phage display in non-aqueous media.

Remission inversion and no transplant-related mortality--a single centre experience of autologous stem cell transplantation in malignant lymphoma

Between 1989 and 1998 93 patients with malignant lymphoma were treated, in our centre, with high-dose chemotherapy and autologous stem cell transplantation. Diagnosis according to the REAL-classification were: 38 patients with high-grade lymphoma (diffuse large B-cell lymphoma (DLCL) (n = 26), anaplastic T-cell (n = 5), lymfoblastic (n = 3) and others (n = 4)), 31 patients with low-grade lymphoma (follicular (n = 18), mantle cell (n = 4), B-CLL (n = 3) and others (n = 6)) and, finally, 24 patients with Hodgkin's disease. The source of stem cells was bone marrow (14 patients), peripheral blood stem cells (64 patients) or a combination of both sources (15 patients). There was no early ( < 100 days) transplant-related mortality. One patient died 11 months post-transplant in unexplained liver failure and all other causes of death were related to relapse of lymphoma. So far, no case of myelodysplastic syndromes or secondary acute leukacmia's has occurred. Overall survival (OS) and progression-free survival (PFS) are: (a) DLCL (26 patients, 4-year probability) OS 40%. PFS 33%; (b) follicular (18 patients, 3-year probability) OS 79%, PFS 52%; (c) Hodgkin's lymphoma (24 patients, 5-year probability) OS 65%, PFS 55%. Out of 52 evaluable patients, 34 (65%) have reached remission inversion. The most important findings are no early transplantation-related mortality, remission inversion in a majority of patients, and so far no cases of secondary myelodysplastic syndromes (MDS) acute myelogenous leukaemias (AML). Concerning OS and PFS, our results seem to be in accordance with other centres.

A transforming growth factor-beta1-mediated bystander immune suppression could be associated with remission of chronic idiopathic thrombocytopenic purpura

Bystander immune suppression has been demonstrated in experimental models of oral immune tolerance induction. This phenomenon is associated with expression of transforming growth factor (TGF)-beta1 and T-helper cell (Th) 2 cytokines. We have studied serum levels of Th cytokines and B- and T-lymphocyte subsets in chronic idiopathic thrombocytopenic purpura (ITP), a disorder in which the production of platelet autoantibodies might be caused by a cytokine network dysregulation. Forty-six patients with ITP were separated into three groups depending on the platelet count (pltc): (1) < 50 x 10(9)/l, (2) 50-150 x 10(9)/l and (3) > 150 x 10(9)/l. We found significantly elevated plasma levels of the Th3 cytokine TGF-beta1 in patients with pltc >150x10(9)/l (23.5+/-2.8ng/ml), compared with patients with pltc <50x10(9)/l (2.3+/-0.6 ng/ml; P<0.0001), patients with pltc 50-150x 10(9)/l (7.2+/-1.7 ng/ml; P<0.0001) and healthy volunteers (9.8+/-1.3 ng/ml; P<0.01). The serum levels of the Thl cytokines interleukin (IL)-2 and interferon (IFN)-y were below the detection limits of the assays. Likewise, the Th2 cytokine IL-4 was not detectable or was very low both in patients and controls. The serum levels of IL-10, a Th2 cytokine, were within the assay range and patients with pltc <50 x 10(9)/l had significantly lower levels (0.6+/-0.1 pg/ml) than both patients with pltc 50-150 x 10(9)/l (1.8 +/- 0.1 pg/ml; P<0.005) and healthy volunteers (1.4+/-0.1 pg/ml; P<0.005). Furthermore, patients with pltc <50 x 10(9)/l and splenectomised patients had significantly higher levels of CD4 + CD25 + activated T cells [26.2 +/- 14.8% (P<0.05) and 26.7+/-11.9% (P<0.005), respectively] than healthy controls (16.5+/-4.0%). Also, the number of natural killer (NK) cells among patients with pltc >150 x 10(9)/l were significantly elevated (26.6+/-16.0%; P<0.05) compared with controls (17.4+/-7.6%). In conclusion, our data corroborate previous findings of elevated numbers of activated T cells in chronic ITP patients with active disease, but neither a clear-cut Th1 nor a Th2 serum cytokine profile could be established. However, ITP in remission was associated with elevated TGF-beta1, which might be a part of a bystander immune suppression. We propose that the effect of possible expression of TGF-beta1 by oral immune tolerance induction deserves to be explored in ITP patients with an active disease.

Plasma thrombopoietin concentrations in response to platelet transfusion therapy

Studies performed in rabbit and mouse models and in a limited number of human subjects, show that transfused platelets bind thrombopoietin (TPO) and decrease its concentration in the circulation. The aim of the present study was to further examine this relationship. The material comprised 12 patients receiving a total of 21 transfusions, as part of the routine clinical treatment. Blood samples were collected from the patients immediately before and 30 min after completion of the platelet transfusion, and the corrected platelet count increment (CCI) was calculated. A commercially available ELISA kit was used to determine plasma TPO concentrations. Statistically significant reductions in median TPO concentration were observed in response to the platelet transfusions. Patients who were refractory to platelet transfusions showed the slightest decrease in TPO concentration. As for the linear regression between change in TPO level and CCI, only borderline significance was observed. Thus, our findings support the concept that platelets can remove TPO from the circulation.

Leukemic transformation of essential thrombocythemia without previous cytoreductive treatment

Blastic transformation of essential thrombocythemia (ET) preceded by chemotherapy is occasionally described in the literature. In ET as well as in other myeloproliferative disorders the leukemogenic effect of alkylating agents and (32)P is well established, and recent reports also indicate a certain leukemogenic effect of hydroxyurea in these disorders. However, leukemic transformation in untreated ET seems to be a rare event. This is probably due to the fact that, at some time during their clinical course, most ET patients receive chemotherapy and are thereby exposed to leukemogenic challenge. We report on a woman with ET who had not received cytoreductive treatment prior to the development of acute myeloid leukemia, indicating that this transformation was a natural progression of her disorder.

Plasma thrombopoietin levels in thrombocytopenic states: implication for a regulatory role of bone marrow megakaryocytes

To evaluate the diagnostic value of thrombopoietin (TPO, c-mpl ligand) measurements, and clarify the regulatory mechanisms of TPO in normal and in thrombocytopenic conditions, the plasma TPO concentration was determined in normal individuals (n = 20), umbilical cord blood (n = 40), chronic idiopathic thrombocytopenic purpura (ITP; n = 16), in severe aplastic anaemia (SAA; n = 3), chemotherapy-induced bone marrow hypoplasia (n = 10), myelodysplastic syndrome (MDS; n = 11), and sequentially during peripheral blood progenitor cell transplantation (n = 7). A commercially available ELISA and EDTA-plasma samples were used for the analysis. The plasma TPO concentration in the normals and umbilical cord blood were 52 +/- 12 pg/ml and 66 +/- 12 pg/ml, respectively. The corresponding values in patients with SAA and chemotherapy-induced bone marrow hypoplasia were 1514 +/- 336 pg/ml and 1950 +/- 1684 pg/ml, respectively, and the TPO concentration, measured sequentially after myeloablative chemotherapy and peripheral blood progenitor cell transplantation, was inversely related to the platelet count. In contrast, the plasma TPO recorded in patients with ITP (64 +/- 20 pg/ml) and MDS (68 +/- 23 pg/ml) were only slightly higher than normal levels. In conclusion, TPO levels were significantly elevated in patients in which bone marrow megakaryocytes and platelets in circulation were markedly reduced, whereas TPO levels were normal in ITP patients, and only slightly increased in the MDS patients. These latter patients displayed a preserved number of megakaryocytes in bone marrow biopsies. Our data support the suggestion that megakaryocyte mass affects the plasma TPO concentration. In thrombocytopenic patients a substantially increased plasma TPO implies deficient megakaryocyte numbers. However, TPO measurements do not distinguish between ITP and thrombocytopenia due to dysmegakaryopoiesis, as seen in MDS patients.

Metabolic control, quality of life, and negative life events: a longitudinal study of well-controlled and poorly regulated patients with type 1 diabetes after changeover to insulin pen treatment

In a previous study of a group of 74 patients with Type I diabetes, quality of life was found to be consistently enhanced a year after transition to multiple injection therapy with the insulin pen, whereas metabolic control (HbA1C) only improved moderately. The aim of the present investigation was to examine quality of life, recent life events, and metabolic control longitudinally in this original study group over a 5-year period beginning 1 year after transition to the insulin pen. Multiple analysis of variance with a repeated-measures design was used to analyze the data longitudinally and compare metabolic control in subgroups of well-controlled and poorly regulated patients during the study period. For the group as a whole, quality of life was found to change only moderately, whereas metabolic control deteriorated significantly across time following transition to the insulin pen. The two subgroups exhibited distinct differences, however, in quality of life, recent life events, and metabolic control patterns. These findings are discussed in terms of the clinical suitability of a multiple injection regimen.

Pen injection and change in metabolic control and quality of life in insulin dependent diabetes mellitus

A second follow-up of metabolic control and quality of life in insulin dependent diabetes mellitus (IDDM) patients who had switched 3 years before from syringe to multiple pen injection treatment, was carried out. A total of 73 consecutive outpatients were enrolled in the initial follow-up study in 1988, 1 year after their changeover to insulin pen, with their metabolic control and quality of life examined. The present study concerns the reexamination of 65 of them in 1990. Their HbA(1c) level was recorded yearly, already from 1987, on. After an enhancement of metabolic control in 1988, exhibited primarily by patients with fewer syringe injections before pen treatment, control up to 1990 was found to have regressed to about baseline level or to have gradually declined. Patients who perceived their ability to self-test blood glucose to have decreased exhibited the least satisfactory course of metabolic control. This is seen to indicate that maintaining self-testing in multiple injection insulin treatment is a very real challenge to this regimen.

Recent life events, gender differences, and the control of insulin-dependent diabetes mellitus. A 2-year follow-up study

In an earlier study of patients with insulin-dependent diabetes mellitus (IDDM), males who reported predominantly negative life events over the previous year and had a poorer social support situation showed poorer HbA1C values than those who reported fewer or no negative life events. For the females it was found that the greater the number of life events reported, especially positive ones, the greater the change for the better was HbA1C over the event year studied. The present study aimed at following up, during the next event year period, various gender-specific patterns obtained in the previous study. For the males, negative life events and HbA1C values were found to be positively related this second event year as well. In addition, more negative life events were reported by those males who, in the previous study, were defined as high-negative eventers. In contrast, for the females, no significant correlations were obtained between life events and HbA1C values for the second event year. The results are discussed in terms of possible differences in psychosocial environment and coping strategies between males and females.

Change in quality of life along with type 1 diabetes

The aim of this study was to recurrently follow quality of life in type 1 diabetes patients who have switched from syringe to multiple pen injection treatment. The insulin pen is a simpler automatically preset device for self-injection. Seventy-three consecutive outpatients were initially examined in 1988, 66 of whom were re-examined in 1990. Quality of life was defined as perceived well-being and life satisfaction, globally as well as within key domains and functions. Various status and retrospective change ratings were repeatedly performed by patients and significant others. For a great majority, quality of life status was fairly stable between 1988 and 1990. Nine subjects with recent incidences of severe socio-medical complications accounted for a great deal (41%) of the decline in composite quality of life status recorded. Future-orientation and the conduct of the multiple regimen declined in the major fairly stable patient group as well. Contrary to the change-in-status outcome referred to, the direct retrospective change ratings in 1990 indicated a certain continuing consistent improvement over the last 2 years. It was minor, though, in comparison with the preceding enhancement attributed to the pen. In spite of the divergent mean outcome, the disparate change parameters correlated. The self-rated life quality trends were corroborated by ratings by significant others. To a certain extent, the mean change bias may reflect coping strategies released by and adopted against the strain of the illness. Probably, these primarily coloured the more sensitive direct retrospective change ratings. Some bias may also be due to a lack of sensitivity of the status ratings. However, the differential change assessments may also tease out and illustrate two separate, equally valid, patient perspectives, one on their current situation and another one on how it has changed. The diabetes illness appears reasonably stable in a majority of the subjects over the study interval. There seem to be some remaining satisfactory quality of life effects of the pen therapy. The study underscores the benefit of undertaking combined retro-/prospective and sufficiently longitudinal analyses with simultaneous dual rating operations, to get the most nuanced overview.

Type II diabetes and quality of life: a review of the literature

In this review, an attempt was made to describe how non-insulin-dependent diabetes mellitus (NIDDM, type II diabetes) affects the life of the ill person. Patients are affected by and cope with this complex disease in different ways, depending on its severity and complications. Influences on well-being therefore also vary--from none to major deterioration. A substantial proportion of patients are primarily affected with fatigue, anxiety, and depression. Deteriorations in cognitive function have also been documented, although diverging evidence exists. Some negative social circumstances have also been noted. Social support, particularly specific support, appears to be helpful, although self-efficacy and health practices seem to be as important. Resistance to compliance with diabetes regimens together with reactions to the demands for increased levels of physical activity are often seen. Systematic focused studies examining how patients and significant others perceive the impact of the disease in retrospect are still awaited. There is a great need for more research on type II diabetes; broad prospective longitudinal follow-up studies monitoring natural disease progression, as well as examining the predictive significance of quality of life, would be welcome.

Alpha 1-adrenoceptor subtypes in the human prostate

OBJECTIVE

To determine the subset of alpha 1-adrenoceptors mediating the functional abstraction of the prostate to noradrenaline.

MATERIALS AND METHODS

Radioligand experiments were performed with membranes prepared from rat 1 fibroblasts transfected with rat alpha 1a, hamster alpha 1b or bovine alpha 1c adrenoceptor cDNA. Human prostatic tissue obtained from transurethral resection of the prostate with full informed consent was submitted to functional in vitro muscle strip experiments.

RESULTS

The binding experiments defined the potential subtype selectivity of various antagonists. Using this information, it was possible to define the functionally important alpha 1-adrenoceptor subtype in the human prostate.

CONCLUSION

This work reports the results of the first functional characterization of the alpha 1c-adrenoceptor subtype. The most functionally important alpha 1-adrenoceptor type in the human prostate appears to be the alpha 1c subtype. This finding may aid the development of prostate-selective adrenoceptor pharmacotherapy.

Coping behaviour and degree of discrepancy between retrospective and prospective self-ratings of change in quality of life in type 1 diabetes mellitus

Quality of life and metabolic control were examined in 74 adults with Type 1 diabetes mellitus in 1988. Sixty-six of the persons were followed up in 1990 with the aim of studying more closely the subgroup that showed a 'major' discrepancy between 'retrospective' and 'prospective' quality of life change ratings. 'Prospective' quality of life change was defined as the difference in assessed quality of life status between 1990 and 1988. 'Retrospective' quality of life change was assessed directly by subjects in 1990 covering the same time period. Data on quality of life, well-being, sociodemographics and metabolic control were collected on both occasions. Recent life-change events and long-term complications were also recorded in 1990. Subjects with 'major' discrepancy reported greater retrospective quality of life improvement, higher quality of life, and greater well-being, as well as lesser occurrence of negative and greater occurrence of positive recent life-change events, than did those with 'minor' discrepancy, despite their exhibiting poorer metabolic control and a higher prevalence of incipient nephropathy. The results are discussed in terms of possible coping and defence strategies.

Background factors, long-term complications, quality of life and metabolic control in insulin dependent diabetes

Sixty-six of 74 adults with Insulin Dependent Diabetes Mellitus (IDDM) examined earlier (1988), were followed up two years later (1990) with the aim of studying the influence of sociodemographic factors, long-term complications and quality of life on metabolic control. It was found that both non-cohabitance and a major discrepancy between quality of life change ratings made prospectively (difference in current QOL ratings made 1990 vs 1988) and retrospectively (assessed in 1990 and covering the same period) were associated with poorer metabolic control, and also that perceived somatic health was linked with better metabolic control. A majority of the persons with a major discrepancy in their quality of life ratings, seen as suggestive of difficulties in their realistically assessing their own life situation, was also found to be non-cohabitant and/or to have incipient nephropathy, indicating these persons to constitute a risk group. In addition, well-regulated subjects were found to rate their bodily health as higher than they did their quality of life, whereas for poorly regulated persons the opposite was the case. The results were seen as pointing to the need of paying special attention clinically to the group of persons characterized here by a major discrepancy in their quality of life change ratings and also as emphasizing the fact that living with IDDM is a balancing act for the individual between satisfying bodily demands to be well-regulated and living in such a way as to perceive quality of life.

Quality of life: status and change (QLsc) reliability, validity and sensitivity of a generic assessment approach tailored for diabetes

The aim was to review the psychometric properties of a generic strategy for assessing status and change in quality of life (QLsc) partly tailored for patients with insulin-dependent diabetes mellitus. Quality of life was defined as perceived well-being and life satisfaction, globally as well as within key domains and functions. The strategy has been developed iteratively and, thereby, proven psychometrically satisfactory across groups and settings. Seventy-three consecutive outpatients were examined in 1988, after a period on multiple injection treatment by insulin pen; 66 were re-examined in 1990. In 1988 and 1990, perceived well-being and life domain status were self-rated. Life domain changes attributed to pen treatment were rated retrospectively in 1988 and subsequent general changes over 2 years rated similarly in 1990. Shortened parallel ratings were performed by significant others. Series of cross-sectional and longitudinal analyses yielded convincing reliability, validity and sensitivity evidence of various kinds for all ratings, irrespective of rater-self or significant other. As expected, a consistent correlational pattern emerged between status self-ratings, suggesting 'the better/worse off' in one sense, the 'better/worse off' in other senses assessed. Moreover, congruent change linkages, suggesting 'the greater change for the better/worse' according to the one type, the 'greater change for the better/worse' according to the other one, were also salient. Fourteen persons with less congruence in the disparate, but parallel change rating parameters appeared to be in a critical disease phase, applying reaction formation or denial like defence mechanisms. In conclusion, the entire cohesive strategy also functioned well in the current setting. It may probably be applied in search for other vulnerable sub-groups and in analyses of coping strategies. It offers rich analytic options especially in evaluational contexts. The study outcome may stimulate development of methodology within this field.

Recent life events, gender, and the control of diabetes mellitus

Sixty-six outpatients with insulin-dependent diabetes mellitus (IDDM) filled in a life event questionnaire reflecting positive and negative life events perceived to have occurred over the past year. The difference in glycosylated hemoglobin (HbA1C) measures obtained before and after the 1-year period in question (Delta-HbA1C) served as a proxy measure of change in metabolic control. Among males, those reporting predominantly negative life events showed poorer metabolic control than those reporting few negative life events or none. Among females, the greater the number of events reported, especially positive ones, the greater the change for the better in HbA1C over the event year studied. These results suggest that life events may be significant to metabolic control in insulin-dependent diabetes. This only becomes apparent, however, when the two genders are analyzed separately, as various relationships found in one sex may be lacking or even opposite to the other sex. The findings also suggest the importance to the diabetic of learning of life events both the relative lack and preponderance of positive as well as negative events.

Urinary bladder function in rats with hereditary diabetes insipidus; a cystometrical and in vitro evaluation

Bladder function was investigated in female rats with hereditary diabetes insipidus (DI) and in healthy controls, in vivo by means of recordings of micturition pattern and cystometry, and in vitro in organ bath experiments. Rats with DI exhibited bladder hypertrophy, the weight of the bladder in these rats being two times that of controls. Recordings of micturition pattern showed that DI-rats had an increased 24 hour diuresis and micturition volume, and decreased micturition interval in comparison with controls. Cystometry recordings revealed increased bladder capacity and micturition volume in DI-rats. However, in these rats basal bladder pressure and threshold pressure were lower than in controls. No significant changes in micturition pressure or bladder compliance were observed, and none of the rats had residual urine. In organ bath studies, a lower maximal response to electrical field stimulation was obtained in bladder strips from DI-rats, than in the control strips, when expressed relative to the response elicited by K(+)-solution. When activated by field stimulation, the DI-bladder strips and the control strips had similar sensitivity to muscarinic receptor blockade with scopolamine at all stimulation frequencies. The sensitivity to carbachol was similar in the two groups. The results suggest that the increased functional demands of DI on the detrusor do not result in major changes pre- or postjunctionally. Further, several of the previously reported urinary bladder changes observed in rats with diabetes mellitus (DM) are similar to those now reported in rats with DI, emphasizing the importance of an increased diuresis per se for the development of alterations in bladder function. However, in contrast to the findings in DM rats, the sensitivity to electrical stimulation of nerves during blockade of muscarinic receptors was similar in DI-rats and their controls. This supports our previous suggestion that the increased resistance to muscarinic receptor blockade of the bladder in DM-rats at low stimulation frequencies is induced by the disease (diabetes mellitus) as such and not by the increased diuresis.

The involvement of potassium channels in the action of ciclazindol in rat portal vein

1. In whole portal veins, ciclazindol (0.3-10 microM) increased the amplitude and duration, but decreased the frequency of spontaneous contractions. Glibenclamide (0.3-10 microM) produced a small increase in contraction amplitude and duration with a small reduction in contraction frequency. 2. In whole portal veins, ciclazindol (1-10 microM) antagonized the relaxant effects of BRL 38227 in a non-competitive manner. Under identical conditions, the effects of glibenclamide (0.3-10 microM) appeared to be competitive. 3. In whole portal veins loaded with 42K, ciclazindol itself (up to 3 microM) had no detectable effect on basal 42K exchange. However, the increase in 42K efflux produced by BRL 38227 (5 microM) was antagonized by ciclazindol (3 microM). Similar effects were produced by glibenclamide (up to 3 microM). 4. In freshly-isolated portal vein cells examined by the whole-cell voltage-clamp technique, ciclazindol (1-100 microM) inhibited the slowly-activating and inactivating transient outward current (ITO) which could be generated at potentials more positive than -30 mV. In addition ciclazindol (1-10 microM) inhibited the non-inactivating K-current (IKCO) induced by BRL 38227 (10 microM). 5. In freshly-isolated portal vein cells under current-clamp conditions, the hyperpolarization produced by BRL 38227 (10 microM) was reversed by ciclazindol (1-10 microM). 6. In porcine brain membrane fragments, glibenclamide (0.65 nM) displaced 50% of the binding of [3H]-glibenclamide whereas ciclazindol (up to 10 microM) had no effect. 7. It is concluded that ciclazindol is a K-channel blocker. Its action is not selective for the channel(s) which carry IKCO but also extends to those which carry ITO.Its inability to displace [3H]-glibenclamide from porcine brain fragments may indicate that antagonism of BRL 38227 by ciclazindol in smooth muscle is exerted at a site different from that of glibenclamide.

Effects of age and streptozotocin-induced diabetes on contents and effects of substance P and vasoactive intestinal polypeptide in the lower urinary tract of the rat

The urinary bladder and urethral content of substance P and vasoactive intestinal polypeptide and the in vitro effects of the peptides on the bladder were studied at 6 weeks and 6 months of streptozotocin-induced diabetes in the rat. The results were compared with those obtained in age-matched control animals. Both short-term and long-term streptozotocin treatment induced a clearcut increase in bladder weight. Bladder substance P content was increased in both groups of diabetic animals but substance P concentration was similar in control and diabetic animals. Vasoactive intestinal polypeptide content was slightly higher in diabetic animals than in controls but vasoactive intestinal polypeptide concentration was significantly lower in the bladders from both short-term and long-term diabetic animals. The bladder contractile response to substance P was similar in all groups of animals and vasoactive intestinal polypeptide was found to be devoid of contractile or relaxatory effects in the rat bladder. No change in urethral weight was seen with diabetes. There were no clear-cut changes in the urethral contents or concentrations of substance P and vasoactive intestinal polypeptide. The study also enabled comparisons between younger (3 months) and older (9 months) rats. This comparison showed a decrease in the concentrations and contents of substance P and vasoactive intestinal polypeptide between young and older rats. The changes were seen in both the bladder and the urethra and were similar in diabetic and normal animals.

The local side effects of transdermally absorbed nicotine

Percutaneous nicotine administration induces predominant sudorific and rubiform responses in the skin which may be accompanied by subtle piloerection, hyperalgesia and pruritus (although these signs are not overtly manifest). These dermal responses are complex and mechanisms have been proposed for the direct nicotine-stimulation of sweat glands, piloerection and vasoconstriction. These reactions are accompanied by secondary activation and release of vasodilator peptides which produce a predominating vasodilator tone following topical administration, this response masking the direct axon reflex-mediated vasoconstriction.

Background, quality of life and metabolic control in patients with insulin-dependent diabetes mellitus

The interference of background characteristics with quality of life and metabolic control in patients with insulin-dependent diabetes mellitus (IDDM) were examined. Seventy-three consecutive outpatients who switched from syringe injections to multiple pen-injection treatment comprised the study group. Perceived status as well as retrospective changes in quality of life, attributed to the new treatment modality, were assessed at follow-up after 9-13 months. Data on metabolic control (HbA1C) were collected at base-line and follow-up. Sub-group comparisons in life quality and metabolic control were performed with regard to differences in sex, age, cohabitation, onset and duration of IDDM. Most of the background characteristics had no or just minor significance for status and change in the life quality and metabolic control of the patients. Cohabitation, however, was linked to a better life quality status pertaining to different domains and a tendency to better metabolic control. In addition, females reported a slightly better health status and a more healthy life style (i.e. eating, drinking and smoking habits) than did males. Extra treatment attention may therefore be justified for non-cohabiting males.

Functional responses of different muscle types of the female rat urethra in vitro

The influence of muscle type on functional responses of the female rat urethra was investigated using morphological and functional in-vitro techniques. The urethral submucosa was found to contain longitudinally or obliquely oriented smooth muscle cells. The muscularis layer is composed of circularly oriented muscle cells. Near the bladder orifice smooth muscle fibres dominate, but in the mid-urethra the vast majority is circularly oriented striated muscle cells. Circular preparations responded to electrical field stimulation in vitro with a rapid contraction. Stimulation with single impulses resulted in a twitch response; frequencies exceeding 5-10 Hz induced a summation and tetanus. The response was unaffected by phenoxybenzamine, propranolol and scopolamine and had a low sensitivity to calcium-free solution but was sensitive to suxamethonium and tetrodotoxin. Using longer impulse trains stimulation evoked also a slow contraction, sensitive to calcium-free solution. In longitudinal preparations stimulation induced a relaxation followed by a contraction, responses much smaller than those seen in the circular preparations. Both preparations relaxed on addition of calcitonin gene-related peptide or capsaicin. The relaxation to calcitonin gene-related peptide was larger than that to capsaicin in longitudinal preparations but equally large in the circular ones. Substance P and 5-hydroxytryptamine contracted both preparations. The longitudinal urethra showed a larger contraction to 5-hydroxytryptamine than to substance P, whereas both substances induced similar responses in the circular preparations. The study shows a similar muscle arrangement in the female rat urethra as described in humans and further points to a functional differentiation between the different types of muscle.

Insulin-pen treatment, quality of life and metabolic control: retrospective intra-group evaluations

The significance of the insulin pen for the quality of life of patients with insulin-dependent diabetes mellitus (IDDM) has been debated. The aim of this study was to empirically investigate whether quality of life and metabolic control improve and whether insulin requirements change subsequent to multiple injection-pen treatment. The study group comprised 72 consecutive outpatients with IDDM. Thirty-eight subjects had an initial daily regimen of one or two injections, and the remaining 34 subjects had three or more injections. All patients had four or five injections per day during pen treatment. Perceived changes in quality of life attributed to pen treatment were assessed retrospectively at follow-up 9-13 months after the changeover. Data on metabolic control (HbA1c) and insulin dose were collected at base-line and follow-up. The life quality of the IDDM-patients improved consistently, a finding corroborated by recent studies with other designs and methods. Metabolic control improved only for those patients who previously had one or two injections. The insulin requirements did not change. In conclusion, the pen contributes to a better life for the IDDM patient. The quality of life changes due to treatment intervention appear to be assessable.

On the reversibility of functional bladder changes induced by infravesical outflow obstruction in the rat

Rats were subjected to infravesical outflow obstruction for six weeks. The bladder function was followed by cytometrical and in vitro investigations and by recordings of micturition pattern before and after removal of the obstruction. Cytometrical investigations showed that outflow obstruction for six weeks induced a bladder instability. Further, in the presence of obstruction the micturition pressure was large as was the bladder capacity and the rats had residual urine. After removal of the obstruction the bladder function rapidly normalized. The bladder instability disappeared within one week, bladder capacity decreased as did the micturition pressure. Moreover, only a minor amount of residual urine was present post-obstruction. In vitro investigation showed that the response to carbachol and to electrical stimulation was similar in normal and obstructed bladders. However, after removal of the obstruction a supersensitivity to carbachol as well as to electrical stimulation had developed. Obstructed bladders showed a markedly decreased response to substance P. The sensitivity to substance P was rapidly enhanced post-obstruction and after four days the response was restored to the control level. The present study shows that the bladder function in rats with infravesical outflow obstruction rapidly normalized after removal of the obstruction. The disappearance of the bladder instability despite the developed supersensitivity to muscarinic receptor stimulation supports the opinion that the bladder instability is not of muscarinic origin.

Effects of cromakalim (BRL 34915) and pinacidil on normal and hypertrophied rat detrusor in vitro

Normal and hypertrophied rat detrusor were investigated in vitro with regard to effects of the K(+)-channel openers pinacidil and cromakalim. Both drugs abolished spontaneous contractile activity and induced a relaxation of normal and hypertrophied detrusor preparations. In both types of preparation, contractions elicited by K+, carbachol or electrical field stimulation were depressed in the presence of the K(+)-channel openers. Responses induced by K+ or electrical stimulation were more reduced in the hypertrophied than in the normal detrusor. Both K(+)-channel openers increased the efflux of 86Rb+ in a concentration-dependent way and this increase was similar in normal and hypertrophied detrusor. If applicable to man, this data suggest that K(+)-channel openers may be effective in the treatment of bladder instability secondary to outflow obstruction.

Urinary bladder and urethral responses to pelvic and hypogastric nerve stimulation and their relation to vasoactive intestinal polypeptide in the anaesthetized dog

The effects on the urinary bladder and urethra of pelvic and hypogastric nerve stimulation and their relation to vasoactive intestinal polypeptides (VIP) were investigated in the anaesthetized dog. Both pelvic and hypogastric nerve stimulation elicited a twofold increase in urinary bladder blood flow and a clear-cut increase in bladder venous effluent VIP concentration. Hypogastric nerve stimulation induced an initial, partly alpha-adrenergic and partly non-adrenergic, non-cholinergic, contraction of the urinary bladder followed by a relaxation. The urethra response was a maintained alpha-adrenergic contraction. Pelvic nerve stimulation elicited a bladder contraction with an initial non-cholinergic peak, whereafter the bladder pressure was maintained at a lower level, an effect which was mainly cholinergic in origin. The urethral response was an initial non-adrenergic, non-cholinergic contraction followed by a maintained cholinergic contractile response. Afferent pelvic nerve stimulation led to an efferent activity that seemed to be a combination of activity in pelvic and hypogastric pathways to the urinary bladder and the urethra. VIP (10 nmol) injected i.v. induced a relaxation of the urinary bladder and the urethra, together with a fall in systemic blood pressure. However, despite high plasma concentrations, no vasodilation was elicited in the urinary bladder. Thus, the main target for the VIP release during pelvic and hypogastric nerve stimulation is probably not the bladder vasculature, but instead perhaps the bladder smooth muscle proper.

Muscarinic supersensitivity in the rat urinary bladder after capsaicin pretreatment

The effects of capsaicin on urinary bladder function have been investigated in adult rats. Ten days after capsaicin treatment immunocytochemical investigations showed a nearly complete disappearance of substance P (SP) and calcitonin gene-related peptide (CGRP) in all parts of the bladder. Recordings of micturition patterns and cytometrical investigations in conscious animals revealed no functional effects of capsaicin treatment. In-vitro experiments showed that the contractile response to substance P was similar before and after capsaicin treatment and CGRP exerted no contractile effects on the urinary bladder in either group of rats. The concentration-response curve to carbachol as well as the frequency-response curve to electrical stimulation were significantly shifted to the left in bladder muscle after capsaicin treatment. However, the maximal responses were similar in control and capsaicin-treated bladders. In the presence of scopolamine the maximal response to electrical stimulation was clearly lower in bladders subjected to capsaicin treatment than in controls. In conclusion, depletion of substance P and CGRP in the rat urinary bladder by capsaicin induced no supersensitivity to these peptides. However, the increased sensitivity to carbachol and to electrical stimulation seen after capsaicin treatment indicates the development of a supersensitivity to muscarinic receptor stimulation. Despite this supersensitivity in vitro no functional effects of capsaicin treatment were found in vivo.

Nerve-mediated functions in the circular and longitudinal muscle layers of the proximal female rabbit urethra

In the present study, nerve mediated functions in the circular and longitudinal muscle layers of the female rabbit urethra were characterized. Based on light microscopic findings, the interest was focused on the proximal third of the organ. A microsurgical dissection technique was developed, allowing separation of the two muscle layers. The following studies were carried out: functional in vitro investigations including exogenous application of drugs and electrical field stimulation, investigations of the release of 3H-noradrenaline (NA), and autoradiography for visualization of muscarinic receptors. The results can be summarized as follows: the adrenergic nervous influence, which was mediated mainly via alpha 1-adrenoceptors, dominated the contractile response of the circular layer and contributed significantly to the contraction of the longitudinal layer. A previously described fast, non-adrenergic, non-cholinergic response was found in the circular muscle layer. This response should probably be ascribed to striated muscle with a different innervation and/or structure than skeletal muscle in general. Muscarinic cholinoceptors were abundant in the outer parts of the urethral wall and decreased in density in luminal direction. A significant cholinergic contractile component was demonstrated in the longitudinal muscle. A non-adrenergic, non-cholinergic nerve-mediated relaxant response was found in both layers, although more pronounced in the circular one. Vasoactive intestinal polypeptide completely relaxed both circular and longitudinal preparations contracted by noradrenaline. A possible basis for an interaction between adrenergic and cholinergic nerve endings was demonstrated in the circular muscle layer. Stimulation of muscarinic receptors on the adrenergic nerve endings markedly reduced the release of 3H-NA. The present results support the findings in previous studies on circularly and longitudinally oriented full-thickness preparations of the female urethra and further underline the differences in structure, innervation and receptor functions between the different muscle layers of the urethral wall.

Effects of variations in extracellular pH on spontaneous contractile activity and response to nerve stimulation in smooth muscle from rat urinary bladder

The effects of variations in extracellular pH have been studied on rat detrusor muscle in vitro. At pH 7.4 a continuous low amplitude spontaneous contractile activity was found. At pH 6.75 the contractions became more regular with periods of relaxation between the contractions which had increased in amplitude. At pH 7.85 the reverse was found. The results are interpreted as a membrane effect of pH. No effect of pH on amplitudes of high-K(+)-induced contractures was found. Carbachol dose-response relations and maximal contraction amplitude to carbachol was similar at pH 7.4 and 6.75. A significant depression in response to nerve stimulation was, however, noted at pH 6.75. We suggest that, while the force output of the activated detrusor smooth muscle cell is unaffected by changes in extracellular pH, a prejunctional inhibition of nerve induced contraction might occur at low pH.

Bladder function in rats with short- and long-term diabetes; effects of age and muscarinic blockade

The development of alterations in urinary bladder function was studied in rats during six months of streptozotocin-induced diabetes. The results were compared with those obtained in age-matched controls. The bladders from the control rats developed with increasing age an increased micturition volume, a decreased micturition interval, and increased bladder compliance and capacity despite an unaltered bladder weight and unaltered passive and active length-tension relations. The effects of muscarinic blockade were somewhat more pronounced in the older control rats. Following streptozotocin 24 hour diuresis increased rapidly to stabilize within two weeks at a level 15 times higher than the original. This was accomplished initially by an increase in the micturition frequency and then gradually by an increased micturition volume. After six weeks bladder weight had increased more than twofold and did not increase further with time. Despite this both micturition volume and bladder capacity increased from six weeks to six months of diabetes. The diabetic bladders had at low frequencies of stimulation a higher resistance to scopolamine than their age-matched controls. At higher frequencies the resistance to muscarinic blockade showed a similar decrease with age as for the controls. The more pronounced decrease in micturition pressure following atropine treatment in six weeks diabetic rats thus suggests an increased excitation frequency during micturition. No supersensitivity to carbachol was found even after six months of diabetes.

Optically addressed spatial light modulators by MBE-grown nipi MQW structures

Promising approaches for achieving optically addressed spatial light modulators (O-SLMs) are investigated based on combining nipi and multiple quantum well structures. Theoretical aspects of photooptic effects achievable in such structures are treated. Test structures are grown by molecular beam epitaxy using two material systems, (In,Ga)As/GaAs and (Al,Ga)As/GaAs. Experiments show large optically controlled modulation of the absorption coefficient in the quantum well layers ( approximately 10(4) cm(-1)), a log power dependence on the control signal, millisecond and shorter time response, and generally predictable behavior. The results are encouraging for several different O-SLM device structures proposed.

Effects of pinacidil and cromakalim (BRL 34915) on bladder function in rats with detrusor instability

Normal rats as well as rats with bladder hypertrophy secondary to outflow obstruction were investigated cystometrically before and after administration of the potassium channel openers pinacidil or cromakalim one mg./kg. orally. In normal rats cromakalim decreased micturition pressure by 15 +/- 6%. A diminished micturition pressure was also seen after pinacidil (by 18 +/- 8%) but this did not achieve statistical significance. Further, no clear-cut effects on bladder capacity, residual volume, basal bladder pressure, threshold pressure, bladder compliance or on bladder wall tension were seen in this group of rats neither in the presence of pinacidil nor cromakalim. Rats with bladder hypertrophy exhibited a significant bladder instability during cystometrical investigations. The mean amplitude of the spontaneous bladder contraction exceeded 20 cm. H2O prior to micturition. Administration of pinacidil and cromakalin decreased the spontaneous contractions to 26 +/- 12% and 22 +/- 7%, respectively, of that seen in the absence of the drugs. Furthermore, pinacidil decreased micturition pressure by 61 +/- 12%. Also cromakalim decreased micturition pressure (by 27 +/- 13%) but this effect did not achieve statistical significance. After both pinacidil and cromakalim these rats tended to develop residual urine. In accordance with the results in normal rats pinacidil and cromakalim showed no effects on bladder capacity, basal bladder pressure, threshold pressure, bladder compliance or on bladder wall tension in rats with bladder hypertrophy. The findings of an almost complete disappearance of spontaneous bladder contractions in rats with bladder instability and a remaining voiding ability after administration of pinacidil or cromakalim suggest that potassium channel openers may be a therapeutic alternative in the treatment of bladder instability associated with outflow obstruction.

Plasma levels of gastrin, somatostatin, VIP, insulin and oxytocin during the menstrual cycle in women (with and without oral contraceptives)

The aim of the present study was to investigate whether plasma levels of gastrin, somatostatin, insulin, oxytocin, VIP and blood glucose levels vary during the menstrual cycle. Therefore, 19 healthy menstruating women (5 of whom were on low-dose oral contraceptives, o.c.) were blood sampled every second to third day during the menstrual cycle. Hormone levels were measured with radio-immunoassay. Gastrin, insulin, VIP and blood sugar levels remained unchanged during the menstrual cycle. Mean somatostatin levels were significantly lower in women receiving o.c. than in women without such medication (p less than 0.05). In women on o.c., somatostatin concentrations were also significantly lower during the menstrual week, than during the rest of the period (p less than 0.01), but in women without o.c., no such change occurred. Mean oxytocin levels were significantly higher in women on o.c. (p less than 0.001) and in these women, oxytocin levels recorded during the menstrual week were significantly lower than during the rest of the period (p less than 0.02). Systolic and diastolic blood pressure values were also significantly higher in women on o.c. (p less than 0.05 and p less than 0.01). In conclusion, these data show that basal plasma concentrations of gastrin, somatostatin, VIP, insulin and glucagon do not vary during the menstrual cycle. However, ingestion of low-dose oral contraceptives causes a significant decrease of somatostatin concentrations and a significant increase in oxytocin levels, suggesting that low doses of estrogens and/or gestagens may influence digestive and metabolic processes.

Contents and effects of substance P and vasoactive intestinal polypeptide in the bladder of rats with and without infravesical outflow obstruction

The concentrations of substance P and vasoactive intestinal polypeptide (VIP) were determined in the upper, middle, and lower part of the bladder of rats with and without infravesical outflow obstruction. In the obstructed animals there was a significant increase in bladder weight and the total amounts of substance P and VIP were increased. However, the concentrations of substance P were significantly lower than in the control bladders. The concentrations of VIP, on the other hand, were significantly higher in the middle and lower parts of obstructed bladders than in the controls. In isolated strips of the normal and obstructed bladders VIP had neither contractile nor relaxant effects. The peptide had no effect on electrically induced contractions. Substance P produced concentration-dependent contractions in both normal and obstructed bladders. However, obstructed bladders were significantly less sensitive than controls. It is concluded that the bladder instability seen in rats with infravesical outflow obstruction cannot be explained only in terms of changes in the bladder content of substance P or VIP.

Different effects of neuropeptide Y on electrically induced contractions in the longitudinal and circular smooth muscle layers of the female rabbit urethra

The effects of neuropeptide Y (NPY) on preparations of isolated longitudinal and circular smooth muscle from rabbit urethra were studied. In both types of muscle, electrically induced contractions and relaxations could be abolished by tetrodotoxin, (TTX). In the longitudinal muscle preparations the contraction was slightly reduced by prazosin, but markedly reduced by scopolamine and NPY. The NPY effect was not influenced by pretreatment with rauwolscine. Pretreatment with NPY had no effect on contractions induced by noradrenaline (NA) or carbachol and the peptide did not relax preparations contracted by these agents. In circular muscle an initial, fast response, not sensitive to prazosin or scopolamine was occasionally observed following electrical stimulation. A slow contraction component was regularly seen; this response was abolished by prazosin. Neuropeptide Y did not influence any of these responses. The preparations were concentration-dependently contracted by NA, whereas carbachol had no effect. Pretreatment with NPY did not affect contractions induced by NA, nor did the peptide relax NA-contracted preparations. In neither longitudinal nor circular muscle strips did NPY affect the electrically induced TTX sensitive relaxation of NA-contracted preparations. The results suggest that in the rabbit urethra NPY reduces contractions in the longitudinal muscle layer by selectively inhibiting the release of acetylcholine from cholinergic nerves. Neuropeptide Y did not appear to have any significant postjunctional effects nor to interfere with the release, or effects of NA or other transmitter agents. The physiological importance of the urethral effects of NPY remains to be established.

Cystometrical and in vitro evaluation of urinary bladder function in rats with streptozotocin-induced diabetes

Micturition pattern and cystometric characteristics were determined in control rats, and in rats with streptozotocin-induced diabetes (six weeks duration). The diabetic rats had an increased frequency of micturition, an increased micturition volume, and an increased 24 hr. urinary output. The cystometry showed that the diabetic bladders had an increased compliance and a higher threshold volume for initiating a micturition reflex. No spontaneous rhythmic contractions were seen during the filling phase, and no residual urine could be detected. While micturition pressure increased, the micturition time was virtually unaltered. In vitro a right-ward shift for passive and active length-tension relations was noted. The observed changes in cystometric characteristics and length-tension relations might probably be explained on the basis of adaptive changes to the increased diuresis involving both sensory and motor control of the urinary bladder.

Tetrodotoxin-resistant contractions induced by electrical stimulation of bladder muscle from man, rabbit and rat

Isolated detrusor preparations from man, rabbit and rat were suspended in an organ bath and isometric tension was recorded. The preparations were stimulated electrically in the presence of Bay K8644 and nifedipine before and after neuronal blockade with tetrodotoxin. Transmural electrical stimulation produced frequency-dependent contractions in all preparations. Bay K8644 significantly increased and nifedipine decreased these contractions. TTX effectively suppressed the response to electrical field stimulation in all species. When Bay K8644 was added to TTX blocked preparations, the responses to electrical stimulation were partly restored in bladder strips from man and rat. No increase in response was seen in the rabbit preparations. However, if the extracellular K+-concentration was increased to 10 mM (which per se did not affect the response) Bay K8644 significantly increased the contractions. All responses elicited by electrical stimulation in the presence of TTX were abolished by nifedipine. It is concluded that if the bladder smooth muscle is exposed to factors that can increase its sensitivity to contractile agents, this may result in uncontrolled (unstable) bladder contractions. Such contractions may use the 'normal' transmitter substances, but may be triggered at a lower stimulus intensity than normal. As a non-specific increase in membrane excitability seems to be associated with an influx of calcium through voltage-sensitive calcium channels, calcium antagonists, together with agents specifically blocking relevant transmitter substances, would offer an effective therapy against the unstable bladder.

Effects of pinacidil on bladder muscle

Infravesical outflow obstruction and bladder hypertrophy are often associated with bladder hyperactivity causing frequency, urge and urinary incontinence. This hyperactivity may be due to a supersensitivity to depolarising stimuli. Drugs that inhibit smooth muscle activity by opening K+ channels, resulting in hyperpolarisation, would therefore seem to be an attractive therapeutic principle. Pinacidil is an effective vasodilator classified as a K+ channel opener. The drug has been shown to effectively depress spontaneous contractile activity, the contractions induced by low (less than 40 mmol/L) concentrations of K+, carbachol and by electrical stimulation of nerves in isolated normal human bladder tissue and also in normal and hypertrophied rat bladder. The effect was more pronounced in hypertrophied detrusor. Pinacidil in concentrations inhibiting muscle activity also increased the efflux of 86Rb in bladder tissue. In vivo pinacidil suppressed spontaneous contractile activity in rats with infravesical bladder obstruction and detrusor hypertrophy. The findings make K+ channel openers an interesting, potentially useful therapeutic principle in hyperactivity associated with bladder hypertrophy.

Bladder vasodilatation and release of vasoactive intestinal polypeptide from the urinary bladder of the cat in response to pelvic nerve stimulation

In the feline urinary bladder blood flow was determined by means of a direct blood flow measurement technique before and during pelvic nerve stimulation. Simultaneous sampling of venous blood from the bladder was performed, and the output of vasoactive intestinal polypeptide (VIP) was determined by means of radioimmunoassay. Maximal stimulation of the pelvic nerves led to a clearcut increase in intravesical pressure and a small but sustained increase of blood flow in the bladder wall. These changes were associated with a drastic increase in VIP output from the bladder, increasing from a control level of 0.2 fmol./min. to 15 fmol./min. during stimulation. The results suggest that VIP might be the neurotransmitter responsible for the vasodilatation in the feline urinary bladder in response to pelvic nerve stimulation. The discrepancy between the moderate blood flow increase and the pronounced increase in VIP-release might, however, indicate that VIP exerts its main effects elsewhere in the bladder than in the vascular bed, for instance the detrusor smooth muscle.