The lactate receptor (HCAR1/GPR81) contributes to doxorubicin chemoresistance via ABCB1 transporter up-regulation in human cervical cancer HeLa cells.

The lactate receptor, also known as hydroxycarboxylic acid receptor 1 (HCAR1/GPR81), plays a vital role in cancer biology. Recently, HCAR1 was reported to enhance metastasis, cell growth, and survival of pancreatic, breast, and cervical cancer cells. This study showed, for the first time, the mechanism of HCAR1-mediated chemoresistance to doxorubicin through regulation of ABCB1 transporter. We observed the HCAR1 agonists L-lactate, D-lactate and 3,5-dihydroxybenzoic acid (DHBA) induced up-regulation of ABCB1. HCAR1 silencing decreased ABCB1 mRNA and protein by 80% and 40%, respectively. Moreover, cellular doxorubicin accumulation decreased by 30% after DHBA treatment, while HCAR1 silencing increased accumulation of ABCB1 substrates by nearly 2-fold. Based on growth inhibition assays, cell cycle analysis, and annexin V staining assays, we demonstrated that HCAR1 enhances cell survival and doxorubicin resistance. Finally, DHBA-stimulated up-regulation of ABCB1 functionality was suppressed by pharmacological inhibition of the PKC pathway. Taken together, our study shows the novel role of HCAR1 in development of chemoresistance in cervical carcinoma HeLa cells via ABCB1 transporter up-regulation.

Analysis of aclarubicin-induced cell death in human fibroblasts.

In the present study we investigated the mode of cell death induced by aclarubicin (ACL) in trisomic (BB) and normal (S-2) human fibroblasts. Cells were incubated with ACL for 2h and then cultured in drug-free medium for up to 96h. Using fluorescence microscopy, agarose gel electrophoresis and comet assay we demonstrate that ACL induced time-dependent morphological and biochemical changes in both cell types. The population of apoptotic cells, analysed by acridine orange and ethidium bromide nuclear staining reached its maximum at 24-48h. Prolonged post-treatment time progressively increased the level of necrotic cells. At 24-48h time points we also observed a significant increase in caspase-3 activity, oligonucleosomal DNA fragmentation and DNA strand breaks. Cotreatment of cells with the specific caspase-3 inhibitor Ac-DEVD-CHO partly reduced the extent of apoptosis and necrosis and DNA degradation. In conclusion, trisomic and normal fibroblasts demonstrate similar response to aclarubicin treatment. Drug induced the apoptotic and necrotic pathway of cell death that was mediated by caspase-3.

Circadian distribution of iron and ferritin in serum of healthy and type 2 diabetic males.

AIM: We examined the circulating levels of iron and ferritin in serum of seven healthy and three insulin non-dependent diabetic (Type 2) males in order to compare their circadian characteristics. METHODS: Blood samples were collected every 3h over a 24h period and were analyzed for serum iron and ferritin. RESULTS: The mean Fe level was significantly higher in healthy than in diabetic subjects: 80.0 +/- 3.3 vs. 63.0 +/- 3.7 microg/dL. The ferritin level was significantly lower in healthy than in diabetic men: 79.8 +/- 4.7 vs. 186.3 +/- 110.5 microg/L. A significant (p < 0.001) time-effect was found by ANOVA and circadian rhythm was detected at p < 0.001 in all data sets when a 24h cosine was fitted to the normalized data. Acrophases were located in mid to late morning for Fe (11:30, vs. 09:22h) and for ferritin (11:10 vs. 11:46h). DISCUSSION: We concluded that there is significant circadian variation in both serum Fe and ferritin, with predictable peaks in the mid to late morning.

Centrally administered PD 140.548 N-methyl-D-glucamine prevents the autonomic responses to duodenal pain in sheep.

Cholecystokinin (CCK) released in the CNS inhibits the analgesic action of exogenous opioids and may antagonize analgesia resulting from the activation of an endogenous pain inhibitory system. The aim of this study was to analyse the central action of PD 140.548 N-methyl-D-glucamine--a peptide antagonist of a specific peripheral type CCK receptor--on animal behaviour, catecholamines (CA) and cortisol concentration, as well as clinical symptoms of visceral pain induced by duodenal distension (DD). A 5 min distension of the duodenum wall, using a 10 cm long balloon filled with 40 and/or 80 ml of water (DD 40 and/or DD 80) at animal body temperature, produced a significant increase in plasma CA and cortisol levels, an increase in the heart rate, hyperventilation and other clinical symptoms (inhibition of rumen motility, bleating, teeth grinding, prostration, urination, defecation) that may be related to pain, proportionally to the degree of intestinal distension. Intracerebroventricular administration of PD 140.548 at the dose of 1 or/and 2 mg in toto 10 min before applying DD 40 completely blocked the increase in blood plasma cortisol, epinephrine (E), norepinephrine (NE) and dopamine (DA) concentration. It is suggested that the central inhibitory action of CCK antagonist on the cortisol and catecholamine release produced by visceral pain is due to the inhibition of peripheral CCK1 type receptors in the central centrifugal descending pain facilitatory system in sheep perhaps via the hypothalamic-pituitary-adrenal axis.

Mechanisms of induction of apoptosis by anthraquinone anticancer drugs aclarubicin and mitoxantrone in comparison with doxorubicin: relation to drug cytotoxicity and caspase-3 activation.

We examined molecular events and morphological features associated with apoptosis induced by anthraquinone anticancer drugs aclarubicin, mitoxantrone and doxorubicin in two spontaneously immortalized cell lines (NIH 3T3 and B14) in relation to cytotoxicity of these drugs. The investigated cells showed similar sensitivity to aclarubicin but different sensitivity to doxorubicin and mitoxantrone: mitoxantrone was the most cytotoxic drug in both cell lines. All three drugs triggered both apoptosis and necrosis but none of these processes was positively correlated with their cytotoxicity. Apoptosis was the prevalent form of cell kill by aclarubicin, while doxorubicin and mitoxantrone induced mainly the necrotic mode of cell death. The extent and the timing of apoptosis were strongly dependent on the cell line, the type of the drug and its dose, and were mediated by caspase-3 activation. A significant increase in caspase-3 activity and the percentage of apoptotic cells, oligonucleosomal DNA fragmentation, chromatin condensation and formation of apoptotic bodies was observed predominantly in B14 cells. NIH 3T3 cells showed lesser changes and a lack of DNA fragmentation. Aclarubicin was the fastest acting drug, inducing DNA fragmentation 12 h earlier than doxorubicin, and 24 h earlier than mitoxantrone. Caspase-3 inhibitor Ac-DEVD-CHO did not show any significant effect on drug cytotoxicity and DNA nucleosomal fragmentation.

Intracerebroventricular administration of PD 140.548 N-methyl-D-glucamine attenuates the release of cortisol and catecholamines induced by duodenal distension in the sheep.

The aim of this study was to determine the influence of mechanically induced duodenal distension (DD) and PD 140.548 N-methyl-D-glucamine (a specific peptide antagonist of a CCK1 receptor) premedication on mechanographical reticulo-ruminal activity, animal general behaviour, catecholamines (CA) and the blood plasma cortisol levels, as well as the clinical symptoms of visceral pain induced by DD in sheep. After 24 h fasting, 6 animals, Polish merino sheep were praeanaesthetised by i.m. injection of ketamine (20 mg x kg(-1) b.w.) and anaesthetised with i.v. infusion of pentobarbital (20 mg x kg(-1) b.w.) and a permanent stainless steel cannula (gate cannula) was inserted inside the lateral cerebral ventricle (controlled by cerebrospinal fluid efflux) 10 mm above the bregma and 5 mm laterally from the midline suture using stereotaxic method. Under the same general anaesthesia and analgesia a T-shaped silicon cannula, was inserted into the duodenum (12 cm from pylorus) and a second one was inserted into the dorsal sac of the rumen. During 7 consecutive days after surgery each animal was treated i.m. with procaine penicillin (300000 I.U..kg(-1) b.w.), dihydrostreptomycine (DHS, 10 microg x kg(-1) b.w.), prednisolone acetate 1.2 mg x kg(-1) b.w.) together and i.m. injection of ketamine (20 mg x kg(-1) b.w.), separetely. The influence of PD 140.548 N-methyl-D-glucamine on the unfavourable effects of duodenal distension using a 10 cm long balloon filled with 40 and 80 ml (DD40 and DD80) water at animal body temperature was investigated in this study. Five minutes DD40 and DD80 caused an immediate and compete inhibition of the reticulo-ruminal frequency, a significant increase in plasma CA and cortisol levels, an increase in the heart rate, hyperventilation and other symptoms of pain, proportionally to the degree of intestinal distension. Intracerebroventricular (i.c.v.) administration of PD 140.548 alone at a dose of 0.25, 0.5, 1 or 2 mg in toto did not significantly change the reticulo-ruminal motility, CA and cortisol concentrations, but 10 min after the i.c.v. infusion (or 10 min before DD) at a dose 1 and 2 mg in toto , it completely blocked the increase of blood plasma cortisol, epinephrine (E), norepinephrine (NE) and dopamine (DA) concentrations for 20 min. In the some time it prevented the reticulo-ruminal atony provocked by DD. It is concluded that PD 140.548 N-methyl-D-glucamine--an antagonist of the central CCK1 receptor can be an effective analgesic agent in duodenal pain. This action is due to the inhibition of peripheral CCK1 type receptor in the central descending nerve pathway, facilitating pain transmission in sheep perhaps in the hypothalamic-pituitary-adrenal axis.

Pharmacological and toxicological aspects of combination of beta-lactam and aminoglycoside antibiotic, prednisolone and procaine hydrochloride on the example of Vetramycin.

Vetramycin is an injectable veterinary compound for animal use only. In veterinary medicine, it has been used for a long time as a bactericidal beta-lactam and aminglycoside antibiotics combination, extending the bactericidal spectrum of these substances. This compound, in addition to bactericidal procaine penicillin and dihydrostreptomycin (DHS), contains also prednisolone acetate and procaine hydrochloride, two biologically active substances. Prednisolone, a glucocorticoide, has an antiinflammatory, antiallergic, antiitchical and analgesic effect. Procaine hydrochloride, in turn, has a local anaesthetic effect and attenuates pain caused by irritable properties of antibiotics at the injection sites. The average dosage of, respectively, procaine benzylpenicillin (I.U./kg(-1) b.w.), DHS (microg/kg(-1) b.w.), prednisolone acetate (microg/kg(-1) b.w.) and procaine hydrochloride (mg/kg(-1) b.w.) in horses, cattle, pigs is 6000-15000, 10-11, 0.24-0.6 and 1.2-3.0; s.i.d., in sheep, foals, calves, piglets is 20000-40000, 10, 0.8-1.6 and 4-8; s.i.d., in dogs and cats is 30000-200000, 10, 0.8-1.6 and 4-8; s.i.d.. Intramammary injection dose (Vetramycin antimastitis ointment in syringe) in cows is 1000000 I.U. of procaine benzylpenicillin + 1000000 I.U. of dihydrostreptycin sulphate per quarter of udder, s.i.d., during 3 successive days.

CCK1 central receptor antagonist prevented the intestinal stress symptoms in sheep.

The aim of this study was to determine the influence of mechanically induced duodenal distension (DD) and lorglumide (CCK1 receptor antagonist) premedication on electrical activity of various parts of gastrointestinal (GI) tract and the blood plasma cortisol level in sheep. The influence of lorglumide on the unfavourable effects of duodenal distension (performed with a balloon filled with water--40 and 80 ml; DD40 and DD80) was investigated in this study. These effects in sheep were as follows: the atony of forestomachs and abomasum and the transitory stimulation of myoelectrical activity of small intestine and distal parts of large intestine. The animals, under general anaesthesia, had electrodes inserted into the muscular layers of the organ, the duodenal fistula and (in another group of animals) also the ruminal fistula. Five minute duodenal distension (DD40 and DD80) caused an immediate and complete inhibition of the frequency of spike bursts as well as reticulo-ruminal and abomasal contractions, but also a transitory significant increase of spike bursts of the intestinal wall. The duodenal distension (DD40 and DD80) caused a significant increase of plasma cortisol concentration. Lorglumide did not significantly change the motility of gastrointestinal tract and cortisol concentration, but 10 min after the intracerebroventricular (i.c.v.) infusion in the doses of 1 and 2 mg in toto (i.e. 25 and 50 micrograms/kg B.W.) it decreased the cortisol concentration by 59.7%, as compared with the control values. Lorglumide administered in the above mentioned doses 10 min before the DD40 prevented all signs of intestinal stress and decreased the release of cortisol, but only for 10 min since the beginning of the duodenal distension. It is concluded, that lorglumide--an antagonist of the central CCK1 receptors can be an effective antistressoric agent in the stomach atony caused by the duodenal distension (mechanical-algetic-emotional stress) in sheep.

[Spectrophotometric determination of molybdenum in vegetables, food and pharmaceutical compounds]. / Spektrofotometryczne oznaczanie molibdenu w materiale roslinnym, zywnosci i preparacie farmakologicznym.

A spectrophotometric method was applied for determination of molybdemun in dried lucerne, grains of soya, peas and bean and vitamin-mineral compound--Multi-tabs. The method is based on the reaction between molybdenum (VI) and 2,3,7-trihydroxyphenylfluorone in the presence of benzyldodecyldimethylammonium bromide. In all samples it was possible to determine molybdenum content directly, after mineralization without its preliminary separation. Accuracy of the determination of molybdenum were checked by the method of standard addition, or by comparison with producer data. To establish the precision of the method, the standard deviation and relative standard deviation were calculate.