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1.
Diabetes Obes Metab ; 16(10): 1016-27, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24965700

ABSTRACT

AIM: This study evaluated the efficacy and safety of canagliflozin, a sodium glucose co-transporter 2 inhibitor, in patients with type 2 diabetes mellitus (T2DM) and within a subset of Stage 3 chronic kidney disease (CKD; estimated glomerular filtration rate [eGFR] ≥ 30 and <50 ml/min/1.73 m(2)). METHODS: In this 52-week, randomized, double-blind, placebo-controlled study, patients (N = 269; mean eGFR, 39.4 ml/min/1.73 m(2)) received canagliflozin 100 or 300 mg and placebo once daily. Efficacy endpoints included changes in glycated haemoglobin (HbA1c), fasting plasma glucose (FPG), body weight and systolic blood pressure (BP); adverse events (AEs) were also recorded. RESULTS: At week 52, canagliflozin 100 and 300 mg reduced HbA1c compared with placebo (-0.19, -0.33 and 0.07%, respectively); placebo-subtracted differences (95% confidence interval) were -0.27% (-0.53, 0.001) and -0.41% (-0.68, -0.14). Canagliflozin also lowered FPG, body weight and BP versus placebo. Overall AE incidence was 85.6, 80.9, and 86.7% with canagliflozin 100 and 300 mg and placebo, respectively. Osmotic diuresis-related AEs were more common with both canagliflozin doses, and incidences of urinary tract infections and volume depletion-related AEs were higher with canagliflozin 300 mg versus placebo. Decreases in eGFR (-2.1, -4.0 and -1.6 ml/min/1.73 m(2)) were seen with canagliflozin 100 and 300 mg compared with placebo. Canagliflozin 100 and 300 mg provided median percent reductions in urine albumin to creatinine ratio versus placebo (-16.4, -28.0 and 19.7%). CONCLUSIONS: Canagliflozin improved glycaemic control and was generally well tolerated in patients with T2DM and within a subset of Stage 3 CKD over 52 weeks.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Diabetic Nephropathies/drug therapy , Glucosides/therapeutic use , Hypoglycemic Agents/therapeutic use , Renal Insufficiency, Chronic/drug therapy , Sodium-Glucose Transporter 2 Inhibitors , Thiophenes/therapeutic use , Aged , Blood Glucose/drug effects , Blood Pressure/drug effects , Body Weight/drug effects , Canagliflozin , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/physiopathology , Diabetic Nephropathies/blood , Diabetic Nephropathies/physiopathology , Disease Progression , Double-Blind Method , Drug Administration Schedule , Female , Glomerular Filtration Rate/drug effects , Humans , Male , Renal Insufficiency, Chronic/blood , Renal Insufficiency, Chronic/physiopathology , Sodium-Glucose Transporter 2/drug effects , Treatment Outcome
2.
Diabetes Obes Metab ; 15(5): 463-73, 2013 May.
Article in English | MEDLINE | ID: mdl-23464594

ABSTRACT

AIMS: Canagliflozin is a sodium glucose co-transporter 2 inhibitor in development for treatment of type 2 diabetes mellitus (T2DM). This study evaluated the efficacy and safety of canagliflozin in subjects with T2DM and stage 3 chronic kidney disease [CKD; estimated glomerular filtration rate (eGFR) ≥30 and <50 ml/min/1.73 m(2)]. METHODS: In this randomized, double-blind, placebo-controlled, phase 3 trial, subjects (N = 269) received canagliflozin 100 or 300 mg or placebo daily. The primary efficacy endpoint was change from baseline in HbA1c at week 26. Prespecified secondary endpoints were change in fasting plasma glucose (FPG) and proportion of subjects reaching HbA1c <7.0%. Safety was assessed based on adverse event (AE) reports; renal safety parameters (e.g. eGFR, blood urea nitrogen and albumin/creatinine ratio) were also evaluated. RESULTS: Both canagliflozin 100 and 300 mg reduced HbA1c from baseline compared with placebo at week 26 (-0.33, -0.44 and -0.03%; p < 0.05). Numerical reductions in FPG and higher proportions of subjects reaching HbA1c < 7.0% were observed with canagliflozin 100 and 300 mg versus placebo (27.3, 32.6 and 17.2%). Overall AE rates were similar for canagliflozin 100 and 300 mg and placebo (78.9, 74.2 and 74.4%). Slightly higher rates of urinary tract infections and AEs related to osmotic diuresis and reduced intravascular volume were observed with canagliflozin 300 mg compared with other groups. Transient changes in renal function parameters that trended towards baseline over 26 weeks were observed with canagliflozin. CONCLUSION: Canagliflozin improved glycaemic control and was generally well tolerated in subjects with T2DM and Stage 3 CKD.


Subject(s)
Body Weight/drug effects , Diabetes Mellitus, Type 2/drug therapy , Glomerular Filtration Rate/drug effects , Glucosides/therapeutic use , Hypoglycemic Agents/therapeutic use , Renal Insufficiency, Chronic/drug therapy , Sodium-Glucose Transporter 2 Inhibitors , Thiophenes/therapeutic use , Aged , Biomarkers/blood , Blood Glucose/drug effects , Blood Glucose/metabolism , Canagliflozin , Comorbidity , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/physiopathology , Disease Progression , Diuresis/drug effects , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Female , Glucosides/administration & dosage , Glycated Hemoglobin/drug effects , Glycated Hemoglobin/metabolism , Humans , Hypoglycemic Agents/administration & dosage , Male , Renal Insufficiency, Chronic/epidemiology , Renal Insufficiency, Chronic/physiopathology , Sodium-Glucose Transporter 2/blood , Sodium-Glucose Transporter 2/drug effects , Thiophenes/administration & dosage , Treatment Outcome , Urinary Tract Infections/etiology
3.
Phys Rev E Stat Nonlin Soft Matter Phys ; 85(4 Pt 2): 046312, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22680579

ABSTRACT

We report experimental and numerical studies of combined natural and magnetic convection of a paramagnetic fluid inside a cubical enclosure heated from below and cooled from above and subjected to a magnetic field gradient. Values of the magnetic field gradient are in the range 9≤|grad|b(0)|(2)|≤900 T(2)/m for imposed magnetic field strengths in the center of the superconducting magnet bore of 1≤|b(0)|(max)≤10 T. Very good agreement between experiments and simulation is obtained in predicting the integral heat transfer over the entire range of working parameters (i.e., thermal Rayleigh number 1.15×10(5)≤Ra(T)≤8×10(6), Prandtl number 5≤Pr≤700, and magnetization number 0≤γ≤58.5). We present a stability diagram containing three characteristic states: steady, oscillatory (periodic), and turbulent regimes. The oscillatory states are identified for intermediate values of Pr (40≤Pr≤70) and low magnetic field (|b(0)|(max)≤2 T). Turbulent states are generated from initially stable flow and heat transfer regimes in the range of 70≤Pr≤500 for sufficiently strong magnetic field (|b(0)|(max)≥4 T).

4.
Neurogastroenterol Motil ; 21(6): 619-26, e23-4, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19220756

ABSTRACT

Acute studies suggested a therapeutic benefit for fundus-relaxing drugs in functional dyspepsia (FD) with visceral hypersensitivity (VH) to gastric distention or impaired accommodation (IA), but long-term studies are lacking. R-137696 is a serotonin-1A (5-HT(1A)) receptor agonist which relaxes the proximal stomach in man. Our aim was to investigate the influence of R-137696 on symptoms in FD with VH or IA. Randomized, double-blind, placebo-controlled, parallel group study of 4 weeks R-137696 2 mg t.i.d. in FD with VH or IA. Symptoms were assessed using the patient assessment of upper gastrointestinal symptom severity index (PAGI-SYM) total score and individual symptom subscales. Barostat studies were performed before and after 4 weeks of treatment. Fifty-three patients (33 VH and 20 IA), 18 men, mean age 40 +/- 13 years were recruited. Twenty-four received placebo and 29 received R-137696. In VH patients, both placebo and R-137696 improved total symptom scores, with a tendency for superiority of placebo (-1.12 vs-0.51, P = 0.07). Placebo was superior for the subscales of early satiety, bloating, fullness and discomfort (all P < 0.05). In IA, both placebo and R-137696 had no significant influence on total or individual symptom scores (-0.08 and -0.27). In VH, both placebo and R-137696 increased the discomfort volume, without a statistical difference between both arms (+120 and +164 mL). In IA, both placebo and R-137696 enhanced accommodation, without a statistical difference between both (+77 and +159 mL). Adverse events were similar for drug and placebo. A 4-week administration of the fundus-relaxing 5-HT(1A) agonist R-137696 failed to significantly improve symptoms, VH or gastric accommodation compared to placebo.


Subject(s)
Dyspepsia/drug therapy , Hypersensitivity/drug therapy , Serotonin 5-HT1 Receptor Agonists , Serotonin Receptor Agonists/therapeutic use , Adult , Cytochrome P-450 CYP2D6/metabolism , Data Interpretation, Statistical , Dextromethorphan , Dose-Response Relationship, Drug , Dyspepsia/physiopathology , Female , Gastric Emptying/drug effects , Gastric Fundus/physiology , Gastrointestinal Motility/drug effects , Humans , Hypersensitivity/physiopathology , Male , Middle Aged , Serotonin Receptor Agonists/adverse effects , Stomach/physiopathology
5.
Neurogastroenterol Motil ; 20(4): 320-9, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18371010

ABSTRACT

Impaired accommodation to a meal has been recognized as a pathophysiological mechanism in functional dyspepsia (FD). Based on observations in tertiary care patients, the drinking test has been proposed as a non-invasive tool to estimate accommodation. Our aim was to assess the reproducibility of the drinking test and its correlation with demographic, symptomatic and pathophysiological parameters in secondary care FD patients and healthy controls. Thirty-four healthy controls and 78 FD patients completed a drinking test (3 respectively 2 times), a gastric emptying study and an FD symptom questionnaire. Factors influencing maximal volume and gastric emptying were determined, and the reproducibility of the drinking test was investigated. The maximal satiety was reached at a lower volume in patients (489 +/- 276 and 503 +/- 248 mL for first and second test respectively vs 937 +/- 428 and 1048 +/- 421 mL, P < 0.0001). The ingested amount depended on age, sex and baseline FD symptom score. Patients' sex, final satiety score, total score for stomach complaints at screening and total symptom score before test accounted for the total symptom score after the test. The slow nutrient drinking test confirms its possible role as an attractive non-invasive and reproducible tool for the diagnosis of impaired accommodation and for the assessment of treatment responsiveness.


Subject(s)
Diagnostic Techniques, Digestive System , Drinking/physiology , Dyspepsia/diagnosis , Adult , Age Factors , Aged , Female , Food , Gastric Emptying/physiology , Humans , Male , Reproducibility of Results , Satiation/physiology
6.
Neurogastroenterol Motil ; 18(10): 919-26, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16961695

ABSTRACT

As fundic dysaccommodation represents one of the pathophysiological mechanisms underlying functional dyspepsia, gastric relaxant agents may serve as a new treatment of this disorder. Previous studies have suggested the involvement of 5HT1 receptors in the control of gastric tone. Our aim was to study the effect of R137696, a novel 5HT1A agonist, on fundus sensorimotor function in healthy volunteers. The effect of single oral doses (1-2 mg) R137696 was evaluated in a double-blind, placebo-controlled manner on fasting fundic volume, visceral perception, distension-evoked symptoms and fundic compliance in 21 healthy male subjects. R137696 increased the proximal stomach volumes in a dose-dependent manner. Distention-evoked symptoms or distention and discomfort threshold were not altered by R137696. A logistic regression model, characterizing the relationships between the volume and the visual analogue scale score for dyspeptic symptoms (nausea, fullness, discomfort, pain and satiety) as a sigmoidal curve, revealed that R137696 had no effect on distension-induced discomfort, fullness, pain and satiety compared to placebo. R137696 relaxes the gastric fundus in fasting conditions but has no effect on distension-evoked dyspeptic symptoms in healthy volunteers.


Subject(s)
Muscle, Smooth/drug effects , Serotonin Receptor Agonists/pharmacology , Stomach/drug effects , Adult , Compliance/drug effects , Dose-Response Relationship, Drug , Double-Blind Method , Humans , Male , Manometry , Muscle Relaxation/drug effects , Pain Measurement
7.
Aliment Pharmacol Ther ; 24(4): 669-77, 2006 Aug 15.
Article in English | MEDLINE | ID: mdl-16827813

ABSTRACT

BACKGROUND: Serotonin and the 5-HT4 receptor play an important role in gastrointestinal motor and sensory functions. While 5-HT4 agonists are known for their prokinetics properties, the effect of 5-HT4 antagonists on upper gastrointestinal functions is largely unknown. AIM: To assess the effect of a 5-HT4 receptor antagonist (R216073) on gastric relaxation and visceral sensitivity in patients with functional dyspepsia. Secondly, the influence of a functional polymorphism in the gene encoding the serotonin transport protein on drug response was determined. METHODS: A double-blind, randomized, placebo-controlled, two-period crossover study was performed in 20 functional dyspepsia patients. The effect of a single dose of 2,000 mg R216073 on gastric relaxation and sensitivity was tested using three-dimensional ultrasonography and a nutrient drinktest. RESULTS: R216073 did not affect partial gastric volumes or upper abdominal sensations scored during three-dimensional ultrasonography (P > 0.05). The maximum tolerated volume or upper abdominal sensations induced by the drinktest were not affected by R216073 (P > 0.05). The serotonin transport protein promoter polymorphism was not associated with any of the end-points of the study. CONCLUSIONS: A single dose of R216073 had no effect on fundic relaxation, drinking capacity, or upper abdominal symptoms in patients with functional dyspepsia.


Subject(s)
Dyspepsia/physiopathology , Gastric Emptying/drug effects , Motor Neurons/drug effects , Serotonin 5-HT4 Receptor Antagonists , Adult , Double-Blind Method , Female , Food , Humans , Male , Middle Aged , Sensation , Time Factors
8.
J Clin Endocrinol Metab ; 80(12): 3532-6, 1995 Dec.
Article in English | MEDLINE | ID: mdl-8530595

ABSTRACT

Turner's syndrome patients with Y mosaicism face a high risk of developing gonadoblastoma. Cytogenetic analysis can fail to detect rare cells bearing a normal or structurally abnormal Y chromosome (low level Y mosaicism). We screened 53 individuals with Turner's syndrome for presence of sex-determining region Y (SRY), the testis-specific protein, Y encoded, gene, and the Y centromeric DYZ3 repeat using nested polymerase chain reaction (PCR). Thirty girls (57%) had the 45,X karyotype, determined through standard analysis of blood lymphocytes. The remaining 23 girls (43%) were mosaics and/or had structural abnormalities in 1 X-chromosome. Genomic DNA from blood leukocytes was amplified using 2 rounds of PCR. This method was sensitive enough to detect 0.0001% male DNA on a female background. None of 53 Turner's syndrome cases was positive for Y-specific loci after the first round of PCR. After the second round, 2 of 53 Turner's syndrome cases were positive for SRY mapping to the distal short arm of chromosome Y. In 1 SRY-positive subject, the karyotype was 45,X, and in the other, it was 46,Xi(Xq). None of 53 Turner's syndrome individuals, including the 2 SRY-positive subjects, were positive for the testis-specific protein, Y encoded, gene on the proximal short arm of chromosome Y or the centromeric DYZ3 repeat. These data exclude low level Y mosaicism in almost all Turner's syndrome cases tested.


Subject(s)
Mosaicism , Turner Syndrome/genetics , Y Chromosome , Base Sequence , Child , Cytogenetics/methods , Female , Humans , Molecular Sequence Data , Oligonucleotide Probes/genetics , Polymerase Chain Reaction/methods , Sensitivity and Specificity
9.
Eur J Endocrinol ; 133(6): 754-60, 1995 Dec.
Article in English | MEDLINE | ID: mdl-8548063

ABSTRACT

The induction of opioid peptides derived from cells of the immune system is postulated to be the main mechanism involved in the immunomodulatory role of melatonin. In this study, it has been demonstrated for the first time that melatonin can act on the level of proopiomelanocortin (POMC) gene expression. The effect of the pineal hormone, administered in late-afternoon subcutaneous injections, was studied in the immune organs of adult male Wistar rats by means of a highly sensitive reverse transcription polymerase chain reaction method (RT-PCR), followed by polyacrylamide gel electrophoresis and densitometric analysis of the bands. It was demonstrated that melatonin stimulates the expression of the 3rd exon of the POMC gene in the lymph nodes and in bone marrow. No significant effects of the pineal hormone were observed in the spleen and thymus. The study establishes that the formation of short POMC transcripts in the bone marrow and lymph nodes may be upregulated by melatonin. Moreover, the pineal hormone exerts its effect without antigenic stimulation.


Subject(s)
Bone Marrow/metabolism , Gene Expression Regulation/physiology , Lymph Nodes/metabolism , Melatonin/pharmacology , Pro-Opiomelanocortin/biosynthesis , Pro-Opiomelanocortin/genetics , Animals , Base Sequence , Bone Marrow/chemistry , DNA Primers/chemistry , Densitometry , Dose-Response Relationship, Drug , Electrophoresis, Polyacrylamide Gel , Exons , Gene Expression Regulation/drug effects , Lymph Nodes/chemistry , Male , Melatonin/physiology , Molecular Sequence Data , Oligonucleotides/analysis , Oligonucleotides/chemistry , Oligonucleotides/genetics , Polymerase Chain Reaction , Pro-Opiomelanocortin/analysis , RNA/analysis , RNA/chemistry , RNA/genetics , Rats , Rats, Wistar
10.
Thyroidology ; 6(3): 81-5, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7544999

ABSTRACT

The goal of our present study has been to examine the effects of the atrial natriuretic factor (ANF) on the growth processes in rat thyroid lobes. In the initial in vitro experiment, thyroid lobes were preincubated with rat ANF (Sigma) for 30 min in RPMI 1640 medium with 3H-thymidine (2 microCi/ml), and later on 15% fetal calf serum (FCS), Hepes buffer and the remaining tested substances [TSH 20 mIU/ml, somatostatin (SS) 10(-7)M] were added. Preincubations with ANF were not conducted in the controls and in the group exposed to TSH alone. Incubations of all the examined groups (controls, TSH alone, ANF alone, ANF together with TSH or ANF together with SS) with 3H-thymidine were carried out for 4 hours. We obtained the following results: at none of the examined concentrations (10(-5)M, 10(-7)M, 10(-9)M), did ANF significantly affect the rate of 3H-thymidine incorporation in vitro. Neither did TSH alone nor ANF with TSH jointly significantly influence the process in question. However, we observed increased rates of the 3H-thymidine uptake, following the joint exposure of thyroid lobes to ANF (10(-7)M or 10(-9)M) and SS (10(-7)M), when compared to ANF alone. In the ex vivo in vitro experiment, direct intrathyroidal microinjections of ANF alone or jointly with TSH or SS, were carried out. Twenty four (24) hours after the microinjections, all the animals were sacrificed by decapitation, the thyroid lobes being collected and incubated for 4 hours with 3H-thymidine (2 microCi/ml).(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Atrial Natriuretic Factor/pharmacology , Somatostatin/pharmacology , Thyroid Gland/growth & development , Thyrotropin/pharmacology , Animals , DNA/biosynthesis , Drug Interactions , Kinetics , Male , Rats , Rats, Wistar , Thymidine/metabolism , Thyroid Gland/drug effects
11.
J Pineal Res ; 14(3): 117-27, 1993 Apr.
Article in English | MEDLINE | ID: mdl-8336273

ABSTRACT

In earlier studies from other laboratories it was shown that melatonin decreased ovarian weight in rats and inhibited compensatory hypertrophy of the remaining ovary after unilateral ovariectomy. This study was designed to examine the influence of melatonin on certain indices of ovarian hyperplasia and/or hypertrophy in adult female rats with both ovaries preserved and with either an intact pineal gland or with the pineal gland removed (pinealectomy, PX) or, finally, in sham-PX animals. Similar studies were conducted on rats after unilateral ovariectomy, referring the examined parameters to the remaining intact ovary. The studies included mitotic activity of granulosa layer cells and corpus luteum cells, ovarian weight, ovarian cross-sectional area, cross-sectional area of the granulosa layer of all the Graafian follicles and the cross-sectional areas of the corpora lutea, visible on the ovarian cross-section. On the basis of results, we conclude that: 1) the effect of PX on the processes of ovarian hyperplasia and hypertrophy may vary; analogously, exogenous melatonin administration may influence ovarian hyperplasia and hypertrophy in different ways; 2) PX and exogenous melatonin may, under certain conditions, exert similar biological effects, even synergistic effects; 3) melatonin inhibits ovarian growth processes, while the effects of PX are variable; 4) the results indicate that in experiments performed on rats, with the use of two control groups, i.e., intact and sham-PX, melatonin effects on these two groups may differ.


Subject(s)
Melatonin/pharmacology , Ovariectomy , Ovary/drug effects , Ovary/pathology , Pineal Gland/physiology , Animals , Corpus Luteum/cytology , Female , Granulosa Cells/cytology , Hyperplasia , Hypertrophy , Mitosis/drug effects , Organ Size , Pineal Gland/surgery , Rats , Rats, Wistar
12.
Endokrynol Pol ; 44(3): 271-85, 1993.
Article in English | MEDLINE | ID: mdl-8055796

ABSTRACT

This paper presents the results of studies performed within the Applied Project of the Ministry of Health and Social Welfare and of the Committee for Scientific Research: "Studies on Iodine Deficiency in Poland", including the school children in Lódz City and seven voivodships of the Central Poland. According to the results, the analyzed regions can be regarded as areas of goitrous endemia of a moderate degree (the goitre was found in 32.7% of examined population); the same regions can also be classified among the regions of mild iodine deficiency (the mean iodide concentration in urine was 64.0 micrograms/l). The obtained results prove the to-date's iodine prophylaxis to be not entirely efficient in the areas of interest, demanding an effective model of iodine complementation in diet to be designed.


Subject(s)
Goiter, Endemic/epidemiology , Iodine/deficiency , Adolescent , Child , Female , Food, Fortified , Goiter, Endemic/diagnosis , Goiter, Endemic/prevention & control , Humans , Incidence , Iodine/therapeutic use , Iodine/urine , Male , Poland/epidemiology , Thyroid Gland/anatomy & histology , Urban Health
13.
Cytobios ; 74(297): 97-100, 1993.
Article in English | MEDLINE | ID: mdl-8375191

ABSTRACT

The effect of a single injection of pentagastrin on diamine oxidase (DAO) activity in the rat intestinal mucosa was examined. The animals of subsequent groups were sacrificed by decapitation at 6, 12 and 24 h after the administration of pentagastrin or 0.9% NaCl (controls). Diamine oxidase activity was also tested in entire animals. The intestinal fragments were rinsed with 0.9% NaCl. The mucosal scrapings were frozen in liquid nitrogen. Diamine oxidase activity increased in the 24 h after the administration of pentagastrin, when compared with respective controls. No significant differences at other times were evident. The present data are in agreement with the hypothesis that DAO is an enzyme involved in the negative feedback control mechanism of intestinal mucosa cell proliferation.


Subject(s)
Amine Oxidase (Copper-Containing)/metabolism , Intestinal Mucosa/drug effects , Pentagastrin/pharmacology , Animals , Cell Division , Injections, Intraperitoneal , Intestinal Mucosa/enzymology , Male , Pentagastrin/administration & dosage , Polyamines/metabolism , Rats , Rats, Wistar/metabolism
14.
Cytobios ; 73(293): 89-94, 1993.
Article in English | MEDLINE | ID: mdl-8319500

ABSTRACT

The effects of pinealectomy (PX) and melatonin (Mel) administration on the growth processes of Guerin epithelioma, a malignant tumour derived from spontaneous cancer in Wistar rat uterus, was investigated in five groups of male rats. The mean life span of the rats bearing Guerin tumours (GT) and subjected to PX was shorter than in animals with an intact pineal gland. Mel did not affect the lifespan in rats with intact pineals or in those subjected to PX. Mel decreased the mitotic activity of GT cells in rats with and without the pineal gland. Pathomorphological examination revealed high malignancy of the primary tumour but no metastases. The results confirmed the important role of the pineal gland in 'oncostasis'.


Subject(s)
Melatonin/pharmacology , Neoplasm Invasiveness/prevention & control , Pineal Gland/physiology , Animals , Carcinoma/prevention & control , Life Expectancy , Male , Mitosis/drug effects , Neoplasms, Experimental/prevention & control , Rats , Rats, Wistar
15.
J Pineal Res ; 13(4): 158-66, 1992 Nov.
Article in English | MEDLINE | ID: mdl-1287191

ABSTRACT

Previous studies performed in our laboratory indicated that melatonin, when administered in late afternoon (1600-1800) as s.c. injections for 10 days, exerted an inhibitory effect on thyroid growth in mice and Sprague-Dawley rats. The goal of the present study was to examine the effects of melatonin and other indole substances (5-methoxytryptophol, N-acetylserotonin, 6-methoxytryptamine), administered for 10 days, for either 4, 8, or 10 weeks, on thyroid growth processes in adult male Wistar rats. We have also compared the action of melatonin administered in late afternoon as s.c. injections with effects of the melatonin-released chronically from s.c. implanted beeswax pellets containing 1 mg of the hormone. Additionally, the effects of melatonin injections in animals with the pineal gland removed and in thyroid stimulating hormone (TSH)-injected rats have been studied. We examined the mean mitotic activity rates (MMARs) of thyroid follicular cells (TFC) and the wet thyroid weights. We concluded that melatonin, of the examined substances, is the most potent inhibitor of thyroid growth; the hormone reduced the MMAR of TFC and the thyroid weight at all time-points. 5-Methoxytryptophol, like melatonin, exerted the inhibitory influence on the mitotic activity; however, it did not affect thyroid weight. The influence of other indole substances was much less pronounced. It was shown that melatonin-pellets prevented the inhibitory effect of late afternoon melatonin injections on thyroid growth processes. This observation is consistent with results of other authors concerning the counter-antithyroid effect of melatonin on thyroid hormone secretion. Pinealectomy revealed the stimulatory effect on thyroid growth processes, while melatonin treatment reversed the effect of the surgery.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Indoles/pharmacology , Melatonin/pharmacology , Thyroid Gland/drug effects , Animals , Circadian Rhythm , Delayed-Action Preparations , Indoles/administration & dosage , Injections, Subcutaneous , Male , Melatonin/administration & dosage , Mitosis/drug effects , Organ Size/drug effects , Pineal Gland/surgery , Rats , Rats, Wistar , Thyroid Gland/cytology , Thyrotropin/pharmacology
16.
Thyroidology ; 4(1): 11-5, 1992 Apr.
Article in English | MEDLINE | ID: mdl-1284326

ABSTRACT

The aim of the present study was to examine the effects of melatonin (Mel) and of pinealectomy (PX) [in a long-term experiment in vivo - 10 weeks], as well as of Mel and N-acetylserotonin (NAc-5HT) [in experiments ex vivo in vitro and in vitro], on the rat thyroid growth processes. Additionally, the incubations in vitro of rat thyroid lobes with 3H-thymidine, in the presence of TSH, vasoactive intestinal polypeptide (VIP), VIP-antagonist ([4Cl-D-Ph6, Leu17]VIP), somatostatin (SS), all the substances used separately or jointly in combinations, were performed. It was shown that: (a) Mel--administered in late afternoon injections--decreased, while PX increased examined indices of thyroid growth in vivo, (b) Mel--administered in s.c. implanted pellets--reversed the inhibitory effect of Mel injections, (c) in experiments ex vivo in vitro and in vitro, the inhibitory effect of Mel revealed only for the lowest applied dose/concentration of the hormone, (d) NAc-5HT showed no effect, (e) VIP decreased 3H-thymidine incorporation into DNA of thyroid lobes in vitro and enhanced the inhibitory effect of SS on the process in question, (f) VIP-antagonist failed to reverse the inhibitory action of VIP on the thyroid growth.


Subject(s)
Indoles/pharmacology , Neuropeptides/pharmacology , Pineal Gland/physiology , Thyroid Gland/growth & development , Animals , DNA/metabolism , Male , Melatonin/pharmacology , Mitosis/drug effects , Pineal Gland/chemistry , Rats , Rats, Wistar , Serotonin/analogs & derivatives , Serotonin/pharmacology , Thymidine/metabolism , Thyroid Gland/cytology , Thyroid Gland/drug effects , Thyrotropin/metabolism , Vasoactive Intestinal Peptide/pharmacology
17.
Histol Histopathol ; 7(2): 153-6, 1992 Apr.
Article in English | MEDLINE | ID: mdl-1355378

ABSTRACT

The effects of omeprazole--an inhibitor of gastric acid secretion--on gastrin (G)- and somatostatin (D)-cell density in the gastric antral mucosa epithelium in rats were examined, following a 5-day treatment. It was found that omeprazole increased the density of G-cells, whereas it decreased the density of D-cells. That effect was probably independent of hypergastrinaemia, since it could not be blocked by a simultaneous treatment with proglumide--a gastrin receptor blocker. It is concluded that the observed phenomenon is a direct result of a lower gastric acidity, as a consequence of omeprazole treatment.


Subject(s)
Gastric Mucosa/drug effects , Gastrins/analysis , Omeprazole/pharmacology , Somatostatin/analysis , Animals , Cell Count/drug effects , Gastric Mucosa/cytology , Gastric Mucosa/metabolism , Immunohistochemistry , Male , Octreotide/pharmacology , Omeprazole/antagonists & inhibitors , Proglumide/pharmacology , Rats , Rats, Inbred Strains
18.
Postepy Hig Med Dosw ; 46(2): 173-89, 1992.
Article in Polish | MEDLINE | ID: mdl-1470580

ABSTRACT

This paper summarizes the recent knowledge on the factors stimulating or inhibiting the ovarian growth. In the present review the following factors influencing growth processes in the ovary are discussed: gonadotropins, sex steroids, prolactin, renin, angiotensin II, atrial natriuretic factor (ANF), growth hormone, insulin, prostaglandins, pineal indoleamines, tissue growth factors and others. The role of nervous system is also described in the study. Not only gonadotropins and other stimulatory factors but also inhibitory agents, e.g., melatonin should be considered in the ovarian growth regulation. The hypertrophic and/or hyperplastic processes in the ovary seem to be dependent on either the excess of stimulatory agents or the deficit of the growth inhibitors.


Subject(s)
Growth Substances/physiology , Hormones/physiology , Ovary/growth & development , Atrial Natriuretic Factor/physiology , Dinoprost/physiology , Estradiol/physiology , Female , Humans , Insulin/physiology , Melatonin/physiology , Ovary/cytology , Pituitary Hormones, Anterior/physiology , Renin-Angiotensin System/physiology , Transforming Growth Factors/physiology
19.
Biochem Biophys Res Commun ; 181(3): 1187-91, 1991 Dec 31.
Article in English | MEDLINE | ID: mdl-1764069

ABSTRACT

The effects of 4-h incubation in the presence of melatonin and N-acetylserotonin on the incorporation of [3H]-thymidine into DNA of the rat thyroid lobes were investigated. Additionally, thyroid lobes were incubated in the exposure to melatonin with thyrotropin jointly. Melatonin, when applied in the lowest concentration examined (10(-9)M), inhibited [3H]-thymidine incorporation, the effect of other concentrations (10(-6)M-10(-8)M) being not significant. N-acetylserotonin (10(-6)M) did not affect the rate of incorporation of that labelled nucleoside. As expected, thyrotropin enhanced the [3H]-thymidine incorporation into DNA of thyroid lobes. Melatonin (10(-7)M) suppressed that stimulatory effect of thyrotropin. The participation of melatonin in the regulation of thyroid growth processes is considered.


Subject(s)
DNA Replication/drug effects , Melatonin/pharmacology , Thymidine/metabolism , Thyroid Gland/metabolism , Animals , Dose-Response Relationship, Drug , Drug Interactions , Kinetics , Male , Organ Culture Techniques , Rats , Rats, Inbred Strains , Serotonin/analogs & derivatives , Serotonin/pharmacology , Thyroid Gland/drug effects , Thyrotropin/pharmacology , Tritium
20.
Biochem Biophys Res Commun ; 178(2): 520-5, 1991 Jul 31.
Article in English | MEDLINE | ID: mdl-1859412

ABSTRACT

The effects of 4-h incubation in the presence of bombesin on the incorporation of [3H]-thymidine into DNA of the rat thyroid lobes, collected from animals treated in vivo with a long-acting somatostatin analog (SMS 201-995) or with 0.9% NaCl, were investigated. It was shown that not only in vivo injections of SMS 201-995, but also, unexpectedly, in vitro incubation with bombesin inhibited [3H]-thymidine incorporation. The two examined substances did not reveal any additive action in their inhibitory effects on the thyroid growth.


Subject(s)
Bombesin/pharmacology , DNA Replication/drug effects , Octreotide/pharmacology , Thyroid Gland/metabolism , Animals , Bombesin/antagonists & inhibitors , DNA/biosynthesis , DNA/drug effects , In Vitro Techniques , Kinetics , Male , Rats , Rats, Inbred Strains , Thymidine/metabolism , Thyroid Gland/drug effects , Tritium
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