Semen

About: Semen is a research topic. Over the lifetime, 14571 publications have been published within this topic receiving 407739 citations. The topic is also known as: come & ejaculate.

Seminal plasma proteins: what role do they play?

Abstract: Problem Semen is a heterogenous and complex cell suspension in a protein-rich fluid with different functions, some of them well known, others still obscure. Method of study This paper reviews, comparatively, our current knowledge on the growing field of proteomics of the SP and its relevance in relation to the in vivo situation, for the sake of reproductive biology, diagnostics and treatment. Results Ejaculated spermatozoa, primarily bathing in cauda epididymal fluid, are (in vitro) bulky, exposed to most, if not all, secretions from the accessory sexual glands. In vivo, however, not all spermatozoa are necessarily exposed to all secretions from these glands, because sperm cohorts are delivered in differential order and bathe in seminal plasma (SP) with different concentrations of constituents, including peptides and proteins. Proteins are relevant for sperm function and relate to sperm interactions with the various environments along the female genital tract towards the oocyte vestments. Specific peptides and proteins act as signals for the female immune system to modulate sperm rejection or tolerance, perhaps even influencing the relative intrinsic fertility of the male and/or couple by attaining a status of maternal tolerance towards embryo and placental development. Conclusions Proteins of the seminal plasma have an ample panorama of action, and some appear responsible for establishing fertility.

Properties of human seminal plasma.

Abstract: The pharmacological properties of human seminal plasma are described and a comparison is made between the substance (or substances) responsible for these properties and other pharmacologically active bodies. Human male semen was collected and purified and its effect on blood pressure isolated intestinal strips nonpregnant uterus (all in rabbits) isolated seminal vesicles of guinea pigs and eserinized rectus abdominis of frogs was tested by recording muscle response to injection of the seminal fluid. Results showed that human seminal plasma has a strong vasodilator which produces strong stimulation of plain muscle. This seminal substance could be distinguished from substances found in other tissue extracts having similar vasodilator activities. Threfore it is suggested that the vasodilator may help maintain local vasodilatation in accessory glands and ducts of the male genital tract and ensure an active gaseous exchange between the blood and various seminal secretions. Also postulated is that the oxytocic power of seminal plasma is caused by a substance distinct from this depressor. The seminal oxytocic substance has a histamine equivalent of from .4-.6 mg per cu. cm. The effect of this seminal plasma substance on the eserinized rectus abdominis of frogs was similar to acetylcholine.

HTLV-III in cells cultured from semen of two patients with AIDS

Abstract: Epidemiological results suggest that the etiological agent of the acquired immune deficiency syndrome (AIDS) is transmitted primarily through blood products, semen, and saliva. There is evidence that the human T-cell leukemia (lymphotropic) virus type III (HTLV-III) is this agent. HTLV-III has been isolated repeatedly from T cells obtained from peripheral blood or lymph node tissue of AIDS and pre-AIDS patients and of healthy people believed to have been exposed to the virus. In the present study, HTLV-III was detected in and isolated from T cells present in the seminal fluid of AIDS patients. Mononuclear cells from the semen of AIDS patients and normal individuals were cultured in the presence of T-cell growth factor (interleukin-2). After 6 to 8 days, HTLV-III antigens were transiently expressed by the cells from the AIDS patients but not by those from the normal individuals. When the mononuclear cells from the semen of AIDS patients were cocultured with a permissive human T-cell line, cell cultures were produced that expressed high levels of reverse transcriptase activity, showed retroviral particles by electron microscopy, and were positive for HTLV-III-specific antigens when tested by fixed-cell indirect immunofluorescence with the use of monoclonal antibodies to the p24 and p15 antigens of HTLV-III.