Investigação do envolvimento de subtipos de adrenoceptores α1 no efeito anti-imobilidade da imipramina no teste de suspensão pela cauda

Pós-graduação em Ciências Biológicas (Farmacologia) - IBB

Bupropion treatment increases epididymal contractility and impairs sperm quality with no effects on the epididymal sperm transit time of male rats

Bupropion is a dopamine (DA) and norepinephrine (NE) reuptake inhibitor used as smoking cessation and antidepressant drug with a lower incidence of male sexual dysfunction. We showed previously that sibutramine, a norepinephrine/serotonine reuptake inhibitor, reduced male rat fertility. As there are no studies evaluating the impact of bupropion treatment on spermatic parameters and male fertility, we evaluated the effects of bupropion treatment (15 and 30 mg kg(-1), 30 days) on sexual behavior, spermatic parameters and fertility of male Wistar rats and on the epididymal duct in vitro contractility. Bupropion 15 mg kg(-1) increased the serum luteinizing hormone level and the epididymal duct contractility, but the sperm quality was not affected. At 30 mg kg(-1) bupropion impaired sperm quality increasing the incidence of non-progressive sperm. The male sexual behavior and fertility were not modified at both bupropion doses. These results, in rats, suggest the importance of studies evaluating the effects of bupropion on the human male sperm quality.

Effects of swimming and nandrolone decanoate treatment on vas deferens response to norepinephrine

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Boron transport in Eucalyptus. 2. Identification in silico of a putative boron transporter for xylem loading in eucalypt

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Transporter protein genes are differentially expressed in Acidithiobacillus ferrooxidans LR maintained in contact with covellite

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Functional Characterization of an Aspergillus fumigatus Calcium Transporter (PmcA) that Is Essential for Fungal Infection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

INVOLVEMENT OF SWIMMING-INDUCED ACUTE STRESS IN THE SENSITIVITY OF RAT VAS-DEFERENS TO NOREPINEPHRINE

1. The effects of swimming-induced stress on rat sensitivity to norepinephrine were studied.2. Through microscopic analysis of the stomach from swimming stressed rats significant ulceration was observed, confirming that the stress situation was really present.3. Sensitivity to norepinephrine either in the presence or in the absence of cocaine and propranolol in acutely swimming stressed rats was not altered significantly.4. Bilateral adrenalectomy was performed in rats 2 days before swimming and acute stress resulted in a supersensitivity to norepinephrine, indicating that adrenal glands may, at least, partially mediate the sensitivity to this drug in vasa deferentia isolated from these animals.

Acute swimming stress induces changes in noradrenergic mechanisms in order to maintain the response pattern of the rat vas deferens to norepinephrine

This study investigated mechanisms involved in the maintenance of the functional response pattern of the postjunctional alpha(1)-adrenoceptor in vas deferens isolated from rats submitted to acute swimming stress. The plasma corticosterone levels increased approximately three times after the swimming stress in the nontreated rats as well as after swimming stress in the rats pretreated with desipramine (DMI), yohimbine (YO), or DMI with YO. No alteration was detected in the sensitivity to norepinephrine (NE) in the vasa deferentia from the stressed rats or stressed rats treated with DMI or DMI with YO, in relation to their respective control. However, when the vasa deferentia were previously incubated with DMI, a reduction in sensitivity to NE in organs from stressed rats was observed. Vasa deferentia excised from rats pretreated with YO before the swimming stress showed an increase in postjunctional alpha(1)-response that was abolished by prazosin (PZ). Thus, the neuronal uptake, the prejunctional alpha(2)-adrenoceptors (mediating prejunctional inhibition), the occupancy and functional response of the postjunctional alpha(1)-adrenoceptors, and the emotional stress component were very important for the determination of the noradrenergic response pattern in vas deferens from rats submitted to acute swimming stress. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

NtWBC1, an ABC transporter gene specifically expressed in tobacco reproductive organs

To identify genes specifically or predominantly expressed in the stigmas/styles and to establish their possible function in the reproductive process of plants, a tobacco stigma/style cDNA library was constructed and differentially screened, resulting in the isolation of several cDNA clones. The molecular characterization of one of these clones is described here. After sequencing the cDNA and the isolated genomic clone, it was determined that the corresponding gene encodes a protein containing an ATP-binding cassette, characteristic of ABC transporters. This gene, designated as NtWBC1 (Nicotiana tabacum ABC transporter of the White-Brown Complex subfamily), encodes a protein that contains the typical structure of the 'half-transporters' of the White subfamily. To establish the spatial expression pattern of the NtWBC1 gene, northern blot and real-time RT-PCR analyses with total RNA from roots, stems, leaves, sepals, petals, stamens, stigmas/styles, ovaries, and seeds were performed. The result revealed a transcript of 2.5 kb present at high levels in stigmas and styles and a smaller transcript (2.3 kb) present at a lower level in stamens. NtWBC1 expression is developmentally regulated in stigmas/styles, with mRNA accumulation increasing toward anthesis. In situ hybridization experiments demonstrated that NtWBC1 is expressed in the stigmatic secretory zone and in anthers, at the stomium region and at the vascular bundle. NtWBC1 is the first ABC transporter gene with specific expression in plant reproductive organs to be identified and its expression pattern suggests important role(s) in the reproductive process.

Cognitive and olfactory deficits in Machado-Joseph disease: A dopamine transporter study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of the contraction induced by norepinephrine and clonidine in the isolated guinea-pig ileum

Norepinephrine (NE) and clonidine produce a phasic, dose-dependent contraction of the isolated guinea-pig terminal ileum. The effect of NE was blocked by prazosin which produced a parallel rightward shift of the concentration-effect curve to NE, with a significant depression of maximum effects. Yohimbine and indomethacin noncompetitively blocked, whereas practolol potentiated, the contractile effect of NE. The contractile effect of clonidine was not antagonized by indomethacin or atropine. These results suggest that the isolated guinea-pig terminal ileum has excitatory receptors sensitive to clonidine stimulation and excitatory alpha receptors sensitive to blockade by prazosin, and that the activation of the latter may be related to the activation of endogenous prostaglandin synthesis.

Role of androgenic deprivation on the contractile response to norepinephrine in vas deferens isolated from rats submitted to swimming-stress

The effects of androgenic deprivation induced by castration on the norepinephrine contractile response of vas deferens from rats, which have been submitted to acute swimming-stress were determined. Acute swimming-stress led to subsensitivity to norepinephrine in vas deferens excised from intact rats. Similarly, castration also induced subsensitivity to norepinephrine, but no further subsensitivity occurred in organs from castrated rats submitted to acute stress. The results indicate a different response to norepinephrine in terms of relative responsiveness ratio, when vas deferens was excised from castrated rats or castrated rats submitted to acute stress. It is suggested that androgenic steroids modulate the recovery of homeostasis in rat vas deferens during acute stress, and that this effect may involve mechanisms that affect both the sensitivity of adrenergic receptors and the system of neuronal uptake of catecholamines.