Glucocorticoids modulate behavioral effects induced by dopaminergic agonists in rats.

Studies showing the presence of glucocorticoids, and their binding sites in the central nervous system indicate that these hormones may affect central neurotransmission. Both, dopaminergic brain system and glucocorticoids are considered to be involved in certain psychopathological conditions in humans, including depression, addiction or schizophrenia. The present study aimed to investigate the influence of glucocorticoids on dopamine agonists-induced stereotyped behavior and locomotor hyperactivity in rats. The results of the experiment demonstrate that prior to administration of prednisolone (4, 6, 10 or 20 mg/kg) or dexamethasone (4 or 8 mg/kg) intensified and prolonged the stereotypy induced by apomorphine (1 mg/kg sc) or amphetamine (2 mg/kg ip). The effect of dexamethasone was more potent. Amphetamine (0.4 mg/kg)- or amantadine (50 mg/kg)-induced locomotor hyperactivity was significantly reduced in rats pretreated with dexamethasone at a dose of 8 mg/kg or 4 mg/kg. Our observations suggest that exogenous glucocorticoids may enhance the activity of the dopaminergic agonists in the striatum but reduce it in the mesolimbic system of rats.

ACTH 4-9 analogue facilitates the antiimmobility effect of antidepressants and dopamine agonists in swimming rats.

Evidence exists that the 4-10 or 4-9 fragments of adrenocorticotropic hormone (ACTH) produce some behavioral effects in animals and in humans. The present study was designed to investigate whether ACTH 4-9 interferes with the effects of antidepressants: fluoxetine (FLU), fluvoxamine (FOX), selegiline (SEL) or dopamine agonists: piribedil (PRB) or quinpirol (QPR) in forced swimming test and in open field in rats. ACTH 4-9 was given in a single dose (25, 50 or 100 micrograms/kg) or for 7 days (50 micrograms/kg/day), alone or together with antidepressants or dopamine agonists. It was shown that ACTH 4-9 alone did not influence the behavior of rats. However, when given in a single dose, ACTH 4-9 potentiated the antiimmobility effect of all antidepressants and dopamine agonists. ACTH 4-9 given for 7 days, facilitated only the effect of selegiline. The results suggest a functional interaction of ACTH 4-9 with serotonergic and dopaminergic brain mechanisms of drugs action.

Prolonged treatment with beta-adrenoceptor antagonists counteracts the aggression deficit induced by chronic stress.

Chronic stress-induced behavioral disturbances have been used as experimental models of depression. One of them is the deficit of fighting behavior induced by 16-day application of various unpredictable stressors. In the present study we investigated the effect of beta-adrenoceptor antagonists (propranolol, pindolol, nadolol and acebutolol) on electric footshock-induced fighting behavior in chronically stressed (14 various stressors over 16 days) male Wistar rats. It was found that the number of fighting attacks was reduced by about 50-80% in the rats submitted to chronic stress. Prolonged, 14-day, but not acute, treatment with propranolol, pindolol or nadolol (but not acebutolol) counteracted the deficit of aggression induced by chronic stress. It is suggested that beta-adrenoceptor antagonists which penetrate the blood-brain barrier may prevent the behavioral changes induced by chronic stress.

[Effect of beta 2-adrenergic agonists on neurotoxic action of aminophyllines]. / Wplyw agonistów beta 2-adrenergicznych na neurotoksyczne dzialanie aminofiliny.

The purpose of the present investigation was to evaluate whether the beta 2-adrenergic agonists affect the pharmacodynamics and pharmacokinetics of aminophylline-induced seizures. Adult male Albino Swiss mice were treated i.p. with salbutamol, fenoterol or terbutaline and 30 min. later they received i.p.aminophylline. During 90 min. observation clonic and tonic seizures and also mortality of mice were registered. Moreover the influence of beta 2-adrenomimetics on electroshock-induced seizure threshold (CS 50) and on plasma aminophylline concentration was estimated. It was found that pretreatment with salbutamol, fenoterol and terbutaline decreased the ED 50 (for clonic and tonic seizures) and LD 50 of aminophylline. Fenoterol decreased but terbutaline increased the CS 50 in mice. Only terbutaline elevated significantly the plasma concentration of aminophylline. The data indicate that concomitant treatment with beta 2-adrenergic agonists together with aminophylline increase the risk of aminophylline-induced seizures. Thus plasma monitoring of aminophylline concentration could be used in all patients treated simultaneously with beta-2-adrenergic agonists and aminophylline.

[The effect of fiberoptic bronchoscopy and bronchoalveolar lavage (BAL) on results of spirometric measurements]. / Wplyw bronchofiberoskopii i plukania oskrzelowo-pecherzykowego (BAL) na wyniki badania spirometrycznego.

The effect of fiberoptic bronchoscopy and bronchoalveolar lavage on the functioning of the respiratory system was studied in 72 patients (42 males and 30 females). The bronchoscopy was performed in the sitting position. Supplemental oxygen was not given to all the evaluated patients. The group included 24 patients with lung cancer, 9 with sarcoidosis, 12 with tuberculosis, 1 with farmer's lung and 10 with other lung diseases (pneumonia, COPD). A control group consisted of 16 patients who were undergoing routine diagnostic endoscopy but who were seen to be without lung disease. Group BF (39 individuals) received only a bronchoscopic examination, group BF+BAL (33 persons) received a bronchoscopy followed by BAL using 140 ml. of normal saline solution as a lavage fluid. After the bronchoscopic examination there were significant differences in all spirometric measurements, except MEF25. The bronchoscopy and bronchoalveolar lavage caused a transient fall in FEV1, VC, MEF50, MEF75 (7.7-9.4%) which was similar in both groups. These measurements returned to normal after 24 hours. The testing of pulmonary functioning before the bronchoscopy was seen to be clinically important for safety of the patient undergoing this procedure.

The effect of calcium channel antagonists on the aggressive behavior in chronically stressed rats.

The influence of some calcium channel antagonists (CaChaA): nifedipine (NIF), nimodipine (NIM), nitrendipine (NITR), cinnarizine (CIN), and flunarizine (FLU) on electric footshock-induced aggressive behavior was investigated in chronically stressed rats. It was found that chronic stress (various stressors over 16 days) reduced the number of fighting attacks (by about 50%) without changing the pain reactivity of rats. The CaChaA given in a single dose (5 mg/kg ip) did not influence the intensity of fighting. However, when the same drugs were administered chronically (5 mg/kg/day) for 14 days they counteracted the reduction of fighting attacks induced by chronic stress. Neither chronic stress nor CaChaA in doses used change the exploratory activity of rats in open field. The obtained results indicate the similarity of CaChaA effects to those of antidepressant drugs in the recovery of aggressiveness reduced by chronic stress.

UV spectrophotometric determination of piperine in pepper preparations: collaborative study.

Eight collaborating laboratories performed replicate analyses for piperine on 5 samples representing pepper raw spice, oleoresins, and soluble seasonings. Piperine is extracted into ethylene dichloride and measured at maximal absorbance 342-345 nm with a UV light source. Piperine content is calculated using an absorbance factor derived from piperine. Intralaboratory coefficients of variation (CVo) ranged from 0.5 to 3.1%; interlaboratory coefficients of variation (CVx) ranged from 3.0 to 5.8%. The method has been adopted as an official method of the American Spice Trade Association and as an official first action method by AOAC.