Basal Concentrations (basal + concentration)

Distribution by Scientific Domains

Selected Abstracts

Localization of Lutheran, a novel laminin receptor, in normal, knockout, and transgenic mice suggests an interaction with laminin ,5 in vivo

Casey L. Moulson
Abstract Laminins are major components of all basement membranes. One laminin that has garnered particular interest, due to its widespread expression pattern and importance during development, is the laminin ,5 chain. In vitro studies have suggested that the Lutheran blood group glycoprotein/basal cell adhesion molecule (Lu), an Ig superfamily transmembrane protein, is a receptor for laminins containing the ,5 chain. However, there are no in vivo studies showing that these proteins are capable of interacting in tissues. We have isolated the mouse ortholog of Lu and characterized its expression and localization in mouse tissues. Lu was primarily found on the basal surface of epithelial cells and on muscle cells adjacent to basement membranes containing laminin ,5. In addition, there was both a dramatic reduction in the basal concentration of Lu in mice lacking laminin ,5, and a significant increase in Lu protein in transgenic mice overexpressing laminin ,5. Together, these data provide the first in vivo evidence for an interaction between Lu and laminin ,5 and support the hypothesis that Lu is a laminin ,5 receptor. We propose that laminin ,5 is involved in concentrating Lu on the basal surface of epithelial cells. This may be one mechanism by which basement membrane signals are transmitted to the cell. 2001 Wiley-Liss, Inc. [source]

Long-term behavioral and neurochemical effects of chronic stress exposure in rats

Simona Mangiavacchi
Rats exposed to acute unavoidable stress develop a deficit in escaping avoidable aversive stimuli that lasts as long as unavoidable stress exposure is repeated. A 3-week exposure to unavoidable stress also reduces dopamine (DA) output in the nucleus accumbens shell (NAcS). This study showed that a 7-day exposure to unavoidable stress induced in rats an escape deficit and a decrease in extraneuronal DA basal concentration in the NAcS. Moreover, animals had reduced DA and serotonin (5-HT) accumulation after cocaine administration in the medial pre-frontal cortex (mPFC) and NAcS, compared with control animals. After a 3-week exposure to unavoidable stress, escape deficit and reduced DA output in the NAcS were still significant at day 14 after the last stress administration. In the mPFC we observed: (i) a short-term reduction in DA basal levels that was back to control values at day 14; (ii) a decrease in DA accumulation at day 3 followed by a significant increase beyond control values at day 14; (iii) a significant reduction in 5-HT extraneuronal basal levels at day 3, but not at day 14. Finally, a significant decrease in 5-HT accumulation following cocaine administration was present in the NAcS and mPFC at day 3, but not at day 14. In conclusion, a long-term stress exposure induced long-lasting behavioral sequelae associated with reproducible neurochemical modifications. [source]

Elective coronary angioplasty with 60 s balloon inflation does not cause peroxidative injury

K. Cedro
Abstract Background The aim of this study was to evaluate the ongoing controversial issue of whether ischemia/reperfusion during elective coronary angioplasty evokes myocardial peroxidative injury. Design We measured indicators of free radical damage to lipids (free malondialdehyde) and proteins (sulphydryl groups) in coronary sinus blood in 19 patients with stable angina who were undergoing elective angioplasty for isolated stenosis of the proximal left anterior descending coronary artery. Ischemia induced by 60 s balloon inflations was confirmed by lactate washout into coronary sinus after deflation, with immediate and 1 min samples. Peroxidative injury was assessed from washout of (a) malondialdehyde measured directly by high performance liquid chromatography and (b) reduced sulphydryl groups, inverse marker of protein oxidative stress. Results Mean lactate concentration immediately after each deflation increased by 120,150% of the initial value, confirming ischemia and showing that blood originated largely from the ischemic region. Lack of myocardial production of malondialdehyde was confirmed by (a) no arteriovenous differences in individual basal concentrations (aortic, range 033,1203 nmol mL,1, mean 782; coronary sinus blood, range 052,1582 nmol mL,1, mean 818), and (b) after deflations, mean concentrations were not significantly different from preocclusion value. There was no decrease in concentration of sulphydryl groups throughout angioplasty. Conclusion Elective coronary angioplasty with 60 s balloon inflations is a safe procedure that does not induce peroxidative myocardial injury as assessed by methods used in the present study. [source]

Endocrine Function Is Altered in Chronic Migraine Patients with Medication-Overuse

HEADACHE, Issue 4 2006
Innocenzo Rainero MD
Objective.,To evaluate the effects of analgesic overuse on endocrine function in patients with chronic migraine and medication-overuse headache (CM-MOH). Background.,Chronic migraine is frequently associated with an overuse of symptomatic medications. Drugs currently used in acute migraine attacks are associated with several endocrine effects. At present, the endocrine effects of medication overuse in chronic migraine patients are unknown. Methods.,Eighteen patients with CM-MOH, diagnosed according to the ICHD-II criteria, and 18 healthy controls received an intravenous administration of GHRH, hCRH, and TRH. Plasma concentrations of GH, TSH, ACTH, and cortisol were measured for a 90-minute period after administration of the specific releasing hormones. Results.,Hormonal basal concentrations were similar in both groups. GH response to GHRH was significantly reduced in patients with CM-MOH in comparison with controls. TRH induced a reduction of TSH concentrations only at the end of the test. After hCRH administration, ACTH and cortisol concentrations were significantly higher in cases than in controls. A significant correlation between duration of the disease and altered hormonal response was found. Conclusions.,Our study shows that both corticotropic and somatotropic functions are significantly impaired in CM-MOH patients and suggests a role for hormones in the development of chronic migraine. [source]

Effect of Environmental Enrichment on Stress Related Systems in Rats

F. Moncek
Abstract The aim of this study was to test whether environmental enrichment alters the status and responsiveness of pituitary-adrenocortical and sympathetic-adrenomedullary hormones in rats. Previous studies have shown that rats kept in an enriched environment differ from those kept in standard cages in dendritic branching, synaptogenesis, memory function, emotionality and behaviour. In male Wistar rats kept in an enriched environment for 40 days, we studied basal concentrations of hormones, endocrine responses to 5-HT1A challenge and responsiveness and adaptation to repeated handling. Environmental enrichment consisted of large plexiglass cages with 10 rats per cage, which contained variety of objects exchanged three times a week. Rats kept in this enriched environment had higher resting plasma concentrations of corticosterone, larger adrenals and increased corticosterone release to buspirone challenge compared to controls. Lower adrenocorticotropic hormone, corticosterone and adrenaline responses to handling were noticed in rats kept in an enriched environment. Exposure to repeated handling led to a more rapid extinction of corticosterone responses in rats kept in an enriched environment. Thus, environmental enrichment leads to pronounced changes in neuroendocrine regulation, including larger adrenals and increased adrenocortical function, which are so far considered to be indication of chronic stress. [source]

Hormonal Response of Female Goats to Active Immunization against a Recombinant Human Inhibin ,-subunit, and establishment of an Enzyme-linked Immunosorbent Assay for Caprine Follicle-stimulating Hormone

M Hennies
The effect of selective immunosuppression of endogenous inhibin in goats on FSH, LH, progesterone and estradiol-17, profiles was studied during the breeding and nonbreeding seasons. Eighteen adult female Boer goats were immunized against the recombinant human inhibin ,-subunit (hINH-,). With the exception of estradiol, which was determined by radio-immunoassay (RIA), all plasma hormone concentrations were determined by ELISA. The ELISA for FSH presented in this paper was established in the authors' laboratory, based on an existing RIA. Mean basal concentrations of FSH were not affected by immunosuppression of endogenous inhibin, nor was there a difference in the amplitude of the pre-ovulatory FSH surge. Immunization against inhibin appears to eliminate the slight secondary rise of FSH occurring 12,20 h after the major surge associated with ovulation. The LH profiles of the immunized goats were characterized by lower basal concentrations both before and after the pre-ovulatory LH surge which itself was reduced by 50% in immunized does. By contrast, concentrations of circulating estradiol were significantly elevated after inhibin-immunization. Progesterone profiles were not affected. Extending immunization into the anoestrous season by a booster injection of hINH-,, implicating oestrus induction with a progestagen and eCG, produced no discernible differences in FSH and LH profiles in comparison with nonimmunized control goats. The findings suggest that in goats, paracrine factors may play a more significant role in controlling follicular activity than a feedback mechanism acting via the pituitary. [source]

Postnatal and postprandial changes in plasma concentrations of glicentin in term and preterm infants

R Tadokoro
Aim: To examined the changes in basal plasma concentrations of glicentin in developing children and the postnatal and postprandial changes in plasma glicentin levels in infants. Methods: Glicentin, an active component of enteroglucagon, is considered to have a significant trophic action on the intestinal mucosa. Fasting plasma concentrations of glicentin in healthy children and in term and preterm infants were measured before and 30 min after feeding during the first 14 d of life. Results: Plasma basal concentrations of glicentin in children under 1 y of age were significantly higher than those in children aged 1 to 15 y. Plasma basal concentrations of glicentin at 5 or 6 d (2496 and 2190 pg/ml) and at 14 d (2987 and 2817 pg/ml) after birth were significantly higher than those at 1 or 2 d (1098 and 1240 pg/ml) after birth in normal birthweight (NBW) and low-birthweight (LBW) infants. There was no significant difference in the glicentin level between infants at 1 or 2 d (1864 pg/ml) and at 5 or 6 d (1910 pg/ml) after birth in very-low birthweight (VLBW) infants, but the levels at 14 d (3310 pg/ml) after birth were significantly higher than either of those levels. Plasma glicentin concentrations after feeding were significantly higher than those before feeding at 1 or 2 d and at 5 or 6 d after birth in NBW and LBW infants, but a significant increase in the plasma glicentin level after feeding was first observed at 14 d after birth in VLBW infants. There were no significant differences in the basal plasma (2401 and 2718 pg/ml) and postprandial (3007 and 3912 pg/ml) glicentin levels between breastfed and formula-fed infants. Conclusion: The results of the study suggest that glicentin may play an important role in intestinal mucosal growth in the early period of life, although its role in VLBW infants should be further investigated. [source]