PubMed Health⌕ Search

Biomedical subjects

O Vilar

Publications and source records attributed to O Vilar.

At least 19 recordsLinked to original sources

Effects of autonomic drugs on contractions of rat seminal vesicles in vivo.

Various autonomic drugs were placed on the peritoneal covering of the seminal vesicles of anaesthetized rats. Adrenaline (which stimulates the alpha-, beta 1- and beta 2-adrenoceptors) and phenylephrine (an alpha-stimulating agent) produced a sudden increase in tonus and in the amplitude and frequency of contractions. Phentolamine (an alpha-blocker) prevented these effects, whereas propranolol (a beta 1- and beta 2-blocker) did not. Phentolamine also abolished the seminal vesicle response to electrical stimulations. Terbutaline (a beta 2-stimulating agent) did not affect the spontaneous activity. There were no differences between the effects of terbutaline alone and those of terbutaline in the presence of propranolol. Moreover, propranolol did not block the contractile response of the gland to adrenaline or to electrical stimulation. These results indicate that alpha-adrenergic receptors are present in the muscle cell membrane of the rat seminal vesicle. The effects of acetylcholine were similar to those produced by adrenaline or phenylephrine although of smaller magnitude. Atropine prevented the effects of acetylcholine, indicating that they are of the muscarinic type.

Acetylcholine↗

Biochemical changes of the human semen produced by chlorambucil, testosterone propionate and human chorionic gonadotropin administration.

Biochemical analysis and morphological studies were carried out in six patients with lymphomas during and after withdrawal treatment with chlorambucil, testosterone propionate (TP) and human chorionic gonadotropins (HCG). In the course of the treatment with chlorambucil patients developed severe oligozoospermia or azoospermia. The spermatogenesis recovered after a variable period of time following suspension of treatment. During the drug administration seminal fructose and citric acid concentrations increase but the recovery after withdrawal takes a longer period of time. Simultaneous treatment with HCG or TP normalized the biochemical parameters without restoring spermatogenesis.

Adolescent↗

Contractile behaviour of rat epididymis after sympathectomy produced by the administration of guanethidine.

The effect of guanethidine (a sympatholytic agent) on epididymal contractions was studied in rats, in order to contribute new data on the role of both the adrenergic and cholinergic nerves in the spontaneous motility of the epididymis and also during ejaculation. The first type of activity was increased when adrenergic innervation was damaged, but the amplitude and frequency of contractions reached normal values approximately 3 hours after beginning the records. Since spermatozoa were eliminated after electroejaculation, the second type of contractions was not affected either. As the epididymis and vas deferens were congested with spermatozoa, it is possible to assume that guanethidine caused a functional obstruction in a distal segment of the genital tract. The increase of spontaneous activity could be the response of the epididymal muscle to overcome this obstruction and, therefore, to cause the elimination of spermatozoa into the urethra, which normally occurs in absence of ejaculations. Finally, no pregnancies occurred among female rats mated with treated males, at least up to 150 days after ending treatment.

Adrenergic Fibers↗

Multiple complexes in human spermatocytes.

Multiple complexes develop during metaphase I in normal human spermatocytes. Usually they form two separate bodies about 1 micron in diameter, composed of tripartite units and a denser matrix. The tripartite units are structurally identical to the components of the central space of synaptonemal complexes (SCs). Formation of the multiple complexes occurs by shedding of SC fragments from a few chromosomal regions at prometaphase I. The combined total length of central elements in each multiple complex is 1 to 3 micron. Multiple complexes remain as cytoplasmic, perinuclear bodies during telophase I and interphase of spermatocytes II, but they were not observed during or after the second meiotic division. Although multiple complexes are initially located in the spindle, they do not show microtubular attachments and seem to be passively moved towards the periphery.

Chromosomes, Human↗