Do effects of propranolol on the skeletal system depend on the estrogen status?

Background: Propranolol, a nonselective β-adrenergic receptor antagonist, was reported to favorably affect the skeletal system in different animal models. The aim of the study was to investigate whether the effects of propranolol on the skeletal system depend on the estrogen status.

Methods: The in vivo experiments were carried out on the following groups of mature female Wistar rats: sham-operated control rats, sham-operated rats receiving propranolol, ovariectomized (OVX) control rats, OVX rats receiving propranolol, OVX rats receiving estradiol, OVX rats receiving estradiol and propranolol.

Effects of olanzapine and paroxetine on phospholipase D activity in the rat brain.

Background: Phospholipase D (PLD) plays a key role in a second messenger system producing phosphatidic acid, mediating, among others, serotonin 5-HT2 receptor activity. The aim of the study was to evaluate a possible effect of atypical antipsychotic drug, olanzapine (OLZ), and selective serotonin reuptake inhibitor (SSRI) antidepressant, paroxetine (PX), on oleate-activated PLD activity in plasma membranes isolated from rat brain cortex.

Methods: PLD activity was determined using a fluorometric assay.

Effects of vigabatrin on the skeletal system of young rats.

Long-term administration of antiepileptic drugs may be connected with the risk of impairment of bone remodeling. Contrary to the reported unfavorable effect of classic antiepileptic drugs on bone metabolism, little is known about the effect of the next generation antiepileptics on bone remodeling. The aim of the present study was to investigate the effect of vigabatrin, as a representative of new antiepileptics, on the skeletal system of young rats, in comparison with conventional drugs--phenytoin and valproic acid.

Effects of curcumin on the skeletal system in rats.

There is increasing interest in the discovery of natural compounds that could favorably affect the skeletal system. Curcumin is a constituent of turmeric, a plant which has been used for centuries as a dietary spice and a traditional Indian medicine. Curcumin has been reported to affect differentiation, activity and the lifespan of osteoblasts and osteoclasts in vitro.

Fluorometric assay of oleate-activated phospholipase D isoenzyme in membranes of rat nervous tissue and human platelets.

Phospholipase D plays a key role in the biosynthesis of phosphatidic acid, a second messenger involved in essential cellular processes. Oleate-activated phospholipase D was the first mammalian phospholipase D isoform to be discovered but is the least known. The study was aimed to test a fluorometric method of assessment of oleate-activated phospholipase D activity in different biological materials.

Administration of caffeic acid worsened bone mechanical properties in female rats.

Natural phenolic acids, commonly present in plants that are normally consumed in the diet, have been reported to exert antiresorptive and/or bone formation increasing activity. The aim of the present study was to investigate the effects of ferulic, caffeic, P-coumaric, and chlorogenic acids on the skeletal system of normal, mature female rats. The phenolic acids (10 mg/kg p.

Natural phenolic acids may increase serum estradiol level in ovariectomized rats.

Natural phenolic acids are commonly present in plants consumed in the diet. Recently we have observed that different natural phenolic acids exert differential effects on the body mass gain in ovariectomized and non-ovariectomized female rats. The aim of the present study was to investigate the effects of ferulic, caffeic, p-coumaric and chlorogenic acids on serum estradiol and total cholesterol levels in ovariectomized and non-ovariectomized rats.

Effect of low-dose tacrolimus coadministered with raloxifene on the skeletal system in male rats.

Tacrolimus is an immunosuppressive drug, used to prevent organ transplant rejection. Immunosuppresants are known to unfavorably affect the osseous system. However, in our previous study on bone histomorphometric parameters we observed that low-dose tacrolimus intensified bone formation.

Thalidomide affects the skeletal system of ovariectomized rats.

Apart from having written an inglorious chapter in the history of medicine, thalidomide is currently being intensely studied because of its multidimensional activity. The aim of this study was to examine the effects of thalidomide on the skeletal system in ovariectomized and non-ovariectomized rats. The experiments were carried out with female Wistar rats, divided into eight groups: sham-operated control rats; sham-operated rats receiving thalidomide at doses of 15, 30 or 60 mg/kg, po; ovariectomized control rats; ovariectomized rats receiving thalidomide at doses of 15, 30 or 60 mg/kg, po.

Effects of natural phenolic acids on the skeletal system of ovariectomized rats.

Recent reports indicate the possibility of antiresorptive and/or bone formation increasing activity of natural phenolic acids, commonly present in plants which are normally consumed in the diet. The effects of 4 natural phenolic acids (ferulic, caffeic, P-coumaric or chlorogenic, 10 mg/kg P. O.

A comparative study of the effects of genistein, estradiol and raloxifene on the murine skeletal system.

Genistein, a major phytoestrogen of soy, is considered a potential drug for prevention and treatment of postmenopausal osteoporosis. The aim of the present study was to compare the effects of genistein, estradiol and raloxifene on the skeletal system in vivo and in vitro. Genistein (5 mg/kg), estradiol (0.

Raloxifene similarly affects the skeletal system of male and ovariectomized female rats.

Raloxifene, a selective estrogen receptor modulator, is used for prevention and treatment of osteoporosis in postmenopausal women. Raloxifene use in male subjects is increasingly considered and a few clinical studies of its effect on bone turnover have already been performed. The aim of the present study was to investigate the effects of raloxifene on the skeletal system of healthy mature male rats.

Influence of enantiomers of 1-naphthylalanine in position 2 of VAVP and dVAVP on their pharmacological properties.

In this study, we described the synthesis and some pharmacological properties of four new analogues of arginine vasopressin (AVP). Two peptides are substituted in position 2 with L-1-naphthylalanine (L-1-Nal) or its D-enantiomer and in position 4 with valine. In the further two compounds, we combined the above modifications with placement into position 1 of 3-mercaptopropionic acid residue (Mpa).

Analogues of arginine vasopressin modified in position 2 and 3 with conformationally constrained dipeptide fragments.

This study describes the synthesis and some pharmacological properties of ten new analogues of arginine vasopressin (AVP) containing a conformationally constrained dipeptide fragment in the N-terminal part of their molecules. Amino acid residues in positions 2 and 3 of AVP and some of its agonistic analogues were replaced with -Phe-Phe and D-Phe-D-Phe, dipeptides having a -CH2-CH2- link bridging two nitrogens. All the new peptides were tested for vasopressor and antidiuretic activities.

Effect of antidepressants on the phospholipase A2 activity in plasma membranes of the rat brain cortex.

The aim of the present study was to establish whether antidepressants (ADs) of potentially different chemical structure and mechanisms of action affected the phospholipase A2 (PLA2) activity in plasma membranes of the rat brain cortex. It was decided to evaluate the influence of imipramine (IMI), amitriptyline (AMI), fluvoxamine (FLU), mianserin (MIA) and tianeptine (TIA) on PLA2 activity after an acute and long-term (4 weeks) drug administration. To study the time-related effects of FLU on PLA2 activity, animals were treated for 1, 7, 14 and 28 days.

Aniracetam attenuates apoptosis of astrocytes subjected to simulated ischemia in vitro.

The aim of the present study was to establish whether aniracetam is capable of protecting cultured rat astrocytes against ischemic injury. Treatment of the cultures with aniracetam (1, 10 and 100 mM) during 24 h ischemia simulated in vitro significantly decreased the number of apoptotic cells. The antiapoptotic effects of the drug were confirmed by the increase of intracellular ATP and phosphocreatine (PCr) levels and the inhibition of the caspase-3 activity.

Piracetam and vinpocetine exert cytoprotective activity and prevent apoptosis of astrocytes in vitro in hypoxia and reoxygenation.

The aim of the present study was to establish whether piracetam (2-pyrrolidon-N-acetamide; PIR) and vinpocetine (a vasoactive vinca alkaloid; VINP) are capable of protecting astrocytes against hypoxic injury. Using the model of astrocyte cell culture we observed the cells treated with PIR and VINP during and after in vitro simulated hypoxia. Cell viability was determined by Live/Dead Viability/Cytotoxicity Assay Kit, LDH release assay and MTT conversion test.