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1.
Reproduction ; 121(5): 647-53, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11427152

RESUMO

Paracrine factors secreted by oocytes and somatic cells regulate many important aspects of early ovarian follicle development in mammals. From activation of dormant primordial follicles to selection of secondary follicles, locally acting factors have been identified that appear to exert important effects on the growth and differentiation of oocytes and granulosa cells. This article summarizes evidence to support a model for bi-directional paracrine communication that is based on developmental regulation of the delivery and reception of paracrine factors at the oocyte-granulosa cell interface. Transzonal projections that originate from granulosa cells and terminate at the oocyte plasma membrane provide a polarized means to orient the secretory organelles of somatic cells. Characterization of transzonal projections in follicles from normal and genetically modified mice reveals dynamic changes in the density and stability of transzonal projections. On the basis of new data analysing the orientation and cytoskeletal content of transzonal projections in mammalian oocytes, a model is proposed for regulation of paracrine growth factor secretion by follicle-stimulating hormone. These findings have immediate implications for ovarian hyperstimulation protocols and follicle culture models as related to the production of mammalian embryos by assisted reproductive technologies.


Assuntos
Células da Granulosa/fisiologia , Oócitos/fisiologia , Folículo Ovariano/crescimento & desenvolvimento , Comunicação Parácrina , Animais , Comunicação Celular , Feminino , Células da Granulosa/ultraestrutura , Homeostase , Humanos , Microscopia Eletrônica , Oócitos/ultraestrutura , Transdução de Sinais
2.
J Comp Neurol ; 349(1): 129-47, 1994 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-7852622

RESUMO

We identified a 'semicircular' compartment of the rat thyropharyngeus muscle at the pharyngoesophageal junction and used the glycogen depletion method to determine how the fibers of this muscle (as well as all others of the pharynx and larynx) are innervated by different cranial nerve branches. The semicircular compartment appears anatomically homologous to the human cricopharyngeus muscle, an important component of the upper esophageal sphincter. While we found very little overlap in the muscle targets of the pharyngeal, superior laryngeal and recurrent laryngeal nerves within the pharynx and larynx, the semicircular muscle receives a dual, interdigitating innervation from two vagal branches: the pharyngeal nerve and a branch of the superior laryngeal nerve we call the dorsal accessory branch. After applying horseradish peroxidase to either of these two nerves, we compared the distribution and number of cells labeled in the brainstem. The dorsal accessory branch conveys a more heterogeneous set of efferent fibers than does the pharyngeal nerve, including the axons of pharyngeal and esophageal motor neurons and parasympathetic preganglionic neurons. The observed distribution of labeled motor neurons in nucleus ambiguus also leads us to suggest that the semicircular compartment is innervated by two subsets of motor neurons, one of which is displaced ventrolateral to the main pharyngeal motor column. This arrangement raises the possibility of functional differences among semicircular compartment motor neurons correlated with the observed differences in brainstem location of cell bodies.


Assuntos
Junção Esofagogástrica/inervação , Nervos Laríngeos/metabolismo , Faringe/inervação , Animais , Estimulação Elétrica , Junção Esofagogástrica/metabolismo , Glicogênio/metabolismo , Masculino , Faringe/metabolismo , Ratos , Ratos Wistar
3.
Minerva Med ; 78(8): 549-52, 1987 Apr 30.
Artigo em Italiano | MEDLINE | ID: mdl-3574741

RESUMO

An in vitro study was conducted into the speed of glycolysis is human erythrocytes. Incubation with Buflomedil does not change the speed of glycolysis.


Assuntos
Eritrócitos/metabolismo , Glicólise/efeitos dos fármacos , Pirrolidinas/farmacologia , Trifosfato de Adenosina/metabolismo , Glicemia/metabolismo , Eritrócitos/efeitos dos fármacos , Humanos
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