Bone metabolism is regulated by interaction between two skeletal cells – osteoclasts and osteoblasts. Function of these cells is controlled by a number of humoral factors, including neurohormones, which ensure equilibrium between bone resorption and bone formation. Influence of neurohormones on bone metabolism is often bimodal and depends on the tissue, in which the hormone is expressed. While hypothalamic beta-1 and beta-2-adrenergic systems stimulate bone formation, beta-2 receptors in bone tissue activate osteoclatogenesis and increases bone resorption. Chronic stimulation of peripheral beta-2 receptors is known to quicken bone loss and alter the mechanical quality of the skeleton. This is supported by the observation of a low incidence of hip fractures in patients treated with betablockers. A bimodal osteo-tropic effect has also been observed with serotonin. While serotonin synthetized in brain has osteo-anabolic effects, serotonin released from the duodenum inhibits osteoblast activity and decreases bone formation. On the other hand, both cannabinoid systems (CB1 receptors in the brain and CB2 in bone tissue) are unambiguously osteoprotective, especially with regard to the aging skeleton. Positive (protective) effects on bone have also been shown by some hypophyseal hormones, such as thyrotropin (which inhibits bone resorption) and adrenocorticotropic hormone and oxytocin, both of which stimulate bone formation. Low oxytocin levels have been shown to potentiate bone loss induced by hypoestrinism in postmenopausal women, as well as in girls with mental anorexia. In addition to reviewing neurohormones with anabolic effects, this article also reviews neurohormones with unambiguously catabolic effects on the skeleton, such as neuropeptide Y and neuromedin U. An important aim of research in this field is the synthesis of new molecules that can stimulate osteo-anabolic or inhibiting osteo-catabolic processes., I. Žofková, P. Matucha., and Obsahuje bibliografii
The paper presents the results of our effort to reveal objective parameters for evaluation of the spa treatment for patients with anxiety-depressive disorders. The study was based on our previous experience with neuroactive steroids and neurosteroids, which play a crucial role in the psychological well-being of patients by maintaining balance of the organism. A total number of 94 steroids were determinated in a group of 70 female patients diagnosed with anxiety-depressive disorders. Patients underwent a month spa treatment while maintaining unchanged medication dosing with SSRI (selective serotonin reuptake inhibitors). The other investigated factors contributing to improving the health of treated subjects were amino-acid homocysteine and serotonin. The blood samples were collected at the beginning and the end of the spa treatment. Serotonin in all patients increased by a relative 23 % (results given as relative differences in percent), while homocysteine decreased by 17.1 %. Statistically significant increases were found in 21 steroids, which indicate activation of the adrenal cortex. It can be assumed, that the overall improvement in the mental condition of patients, which was proved by questionnaire from Knobloch and Hausner, the increase in immune suppressive substances and anti-autoimmune responses, will maintain for a longer time after the spa treatment., M. Bicikova, L. Macova, L. Kolatorova, M. Hill, J. Novotny, D. Jandova, L. Starka., and Obsahuje bibliografii
The present study evaluates the protective role of Quercetin (Quer), against immobilization stress- induced anxiety, depression and cognition alteration in mice using behavioral and biochemical parameters. 24 adult Albino mice were distributed into 2 groups vehicle (n=12; 1 ml/kg) and Quer injected (n=12; 20 mg/kg/ml). The animals received their respective treatment for 14 days. On day 15, after the drug administration, animals were sub-divided into 4 groups (n=6); (i) unstressed + vehicle; (ii) stressed + vehicle; (iii) unstressed + Quer; (iv) stressed + Quer. On day 16, 24 h after the immobilization stress behavioral activities (light-dark activity, elevated plus maze, Morris water maze, and forced swim test) monitored and then animals were decapitated 1 h after the drug administration. Brain samples were collected for biochemical (antioxidant enzymes, AChE, ACh, 5-HT and its metabolite) analysis. The present study indicates the Quer reversed the stress-induced anxiety and depression, in addition, memory performance was more enhanced in stressed group. Following the treatment of Quer, stress-induced elevation of lipid peroxidation and suppression of antioxidant enzymes were also reversed. Administration of Quer decreased AChE in unstressed, while levels of acetylcholine were increased in vehicle and Quer treated stressed animals. The metabolism of 5-HT was increased in Quer treated stressed than unstressed animals. In conclusion, the present finding showed that Quer could prevent the impairment of antioxidant enzymes and also regulate the serotonergic and cholinergic neurotransmission and produce antianxiety, antidepressant effect and enhance memory following 2 h immobilization stress in mice., N. Samad, A. Saleem, F. Yasmin, M. A. Shehzad., and Obsahuje bibliografii
Asthma poses an increased risk for cardiovascular disorders, suggesting that allergy, which is an underlying process in asthma, causes atypical functioning of organs other than lungs. In a previous study in a guinea pig asthma model, we concluded that allergic sensitization increased aorta contractile responses to 5-HT. To further characterize these responses, here we explored the role of the 5-HT2 receptors family. We found that TCB-2 (5-HT2A agonist) and WAY161503 (5-HT2C agonist) induced aorta contractions resembling those elicited by 5-HT but less intense (~43 % and ~25 %, respectively). In these experiments, aortas from sensitized guinea pigs showed increased contractions to TCB-2, but not to WAY161503. In turn, MDL 100907 (5-HT2A antagonist) and RS-102221 (5-HT2C antagonist) caused a notably and a mild reduction of the 5-HT-induced contractions, respectively, with no differences seen between sensitized and non-sensitized tissues. BW723C86 (5-HT2B agonist) did not induce contractile responses and RS-127445 (5-HT2B antagonist) did not modify the contractile responses to 5-HT. In nonsensitized aortas, the pattern of protein expression of receptors was 5HT2B>5-HT2A=5-HT2C, which did not change in sensitized animals. In conclusion, we found that allergic sensitization increased the aorta contractile responses to 5-HT, partly mediated by enhanced responses of 5-HT2A receptors, which was unrelated to changes in the expression of these receptors.
Monoaminergic neurotransmitter 5-hydroxytryptamine (5-HT), also known as serotonin, plays im portant roles in modulating the function of the olfactory system. However, thus far, the knowledge about 5-HT and its receptors in olfactory receptor neurons (ORNs) and their physiological role have not been fully characterized. In the present study, reverse transcription- polymerase chain reaction (RT-PCR) analysis revealed the presence of 5-HT 1A and 5-HT 1B receptor subtypes in mouse olfactory epithelium at the mRNA level. With subtype selective antibodies and standard immunohistochemical techniques, both receptor subtypes were found to be positively labeled. To further elucidate the molecular mechanisms of 5-HT act on the peripheral olfactory transduction, the whole-cell patch clamp techniques were used on freshly isolated ORNs. We found that 5-HT decreased the magnitude of outward K + current in a dose- dependent manner and these inhi bitory effects were markedly attenuated by the 5-HT 1A receptor blocker WAY-100635 and the 5-HT 1B receptor antagonist GR55562. These data suggested that 5-HT may play a role in the modu lation of peripheral olfactory signals by regulating outward potassium currents, both 5-HT 1A and 5-HT 1B receptors were involved in this regulation., S. Gao, ... [et al.]., and Obsahuje seznam literatury
Serotonin (5-hydroxytryptamine) is an ubiquitary monoamine acting as one of the neurotransmitters at synapses of nerve cells. Serotonin acts through several receptor types and subtypes. The profusion of 5-HT receptors should eventually allow a better understanding of the different and complex processes in which serotonin is involved. Its role is expected in the etiology of several diseases, including depre ssion, schizophreni a, anxiety and panic disorders, migraine, hypert ension, pulmonary hypertension, eating disorders, vomiting and irritable bowel syndromes. In the past 20 years, seven distinct families of 5-HT receptors have been identified and various subpo pulations have been described for several of them. Increasing number of 5-HT receptors has made it difficult to unravel the role of 5-HT receptor subpopulations due to the lack of suitable selective agents. The present review describes the different populations and nomenclature of recently discovered 5-HT receptors and their pharmacological relevance. and M. Pytliak ... [et al.].
We tested risperidone and ritanserin, serotonin-S2 receptor antagonists, for their effects on in vitro polyclonal IgG and IgM synthesis by human peripheral blood mononuclear cells (PBMC) stimulated with pokeweed mitogen (PWM). On the basis of the previously reported effect on immune function in vivo risperidone in this study was tested in three different groups of PBMC: healthy donors as well as schizophrenic patients before risperidone treatment and schizophrenic patients after the treatment with risperidone. IgG and IgM production after 7 days of culture was measured by ELISA. Risperidone decreased IgG synthesis (p<0.05) in PBMC of healthy subjects only at the highest concentration (10~6 M) and IgG synthesis enhanced by 5-HT was antagonized by risperidone. This effect, however, was not statistically significant. Neither risperidone nor ritanserin, in the concentration range 10-8- 10~6M, affected IgM synthesis in this group. Risperidone did not affect the production of IgG and IgM by PBMC of schizophrenic subjects in PWM-stimulated cultures both before and after risperidone therapy. The spontaneous production of IgG in PBMC of schizophrenic subjects before therapy was decreased (p<0.05) at concentrations 10-6-10~7 M of risperidone. We conclude that risperidone and ritanserin did not increase polyclonal IgG and IgM synthesis in vitro in contrast to neuroleptics currently used in clinical practice.
Results indicate that vascular responses to temperature stimulation are predominantly impaired in animals with 5-HT deprivation. A hypothesis is therefore raised that the 5-HT system participates in body temperature regulation in such a way asto link the regulatory output with vasomotor pathways. The 5-HT system in the spinal cord has been shown to inhibit the afferent transmission of temperature signals. Therefore, depletion of 5-HT does not prevent sensory transmission, at least at the spinal cord level.