Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0848237 (acute stress)
 4,619 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The criteria for reproductive test selection which were set forth in the beginning of this chapter required that the tests be objective, technically sound, biologically stable, sensitive and feasible. All of the tests which have been discussed can generate objective quantitative data (Table 1). Testicular tonometry appears to be a technically sound procedure which measures a biologically stable parameter, although this remains to be proven. Sperm counts are definitely not a biologically stable parameter. There is insufficient information to judge the biological stability of data obtained from sperm cervical mucus interaction. Data from a number of laboratories suggest that the zona-free hamster egg assay gives stable results when repeated with the same donor, and the tests as performed in specialized laboratories are technically sound at the present time. However, the number of laboratories which can perform the assay is limited. Sensitivity to early toxicity is a very important criterion for test selection. Physical examination does not meet this criterion, endocrine studies do not, and sperm counts do not. Not enough information is currently available to determine the sensitivity of sperm motility assessment. Sperm morphology assessment may be the most sensitive early indicator of reproductive toxicity which is currently available. There is a large body of clinical and basic science literature which suggests that sperm morphology may reflect acute stress effects on the testes. The feasibility of these tests vary. Sperm motility may be feasible only in longitudinal studies in which the video equipment can be set up in a laboratory which is doing repeated assessments. Sperm morphology assessment does not require any specialized equipment in the field. Studies of sperm cervical mucus interaction, for the reasons already stated, remain non-feasible at this time. Tests of sperm-egg interaction are probably feasible if spermatozoa can be shipped to a specialized laboratory for assessment. Thus, there are now a number of new tests for male reproductive function which are available, and which are practical. It is time for this technology to be transferred from the basic science laboratory for application in human reproductive risk assessment.
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PMID:Laboratory tests for human male reproductive risk assessment. 614 22

Testicular apoptosis is activated by stress, but it is not clear which signaling pathway is activated in response to stress. The aim of this study was to investigate whether intrinsic, extrinsic, or both apoptotic signaling pathways are activated by acute and chronic stress. Adult male rats were subjected to cold water immersion-induced stress for 1, 20, 40, and 50 consecutive days. The seminiferous tubules:apoptotic cell ratio was assayed on acute (1 day) and chronic (20, 40, 50 days) stress. Apoptotic markers, including cleaved-caspase 3 and 8, the pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins were also determined after acute and chronic stress induction. Additionally, epididymal sperm quality was evaluated, as well as corticosterone and testosterone levels. An increase in tubule apoptotic cell count percentage after an hour of acute stress and during chronic stress induction was observed. The apoptotic cells rate per tubule increment was only detected one hour after acute stress, but not with chronic stress. Accordingly, there was an increase in Bax, cleaved caspase-8 and caspase-3 pro-apoptotic proteins with a decrease of anti-apoptotic Bcl-2 in both acutely and chronically stressed male testes. In addition, sperm count, viability, as well as total and progressive motility were low in chronically stressed males. Finally, the levels of corticosterone increased whereas testosterone levels decreased in chronically stressed males. Activation of the extrinsic apoptotic pathway was shown by cleaved caspase-8 increase whereas the intrinsic apoptotic pathway activation was determined by the increase of Bax, along with Bcl-2 decrease, making evident a cross-talk between these two pathways with the activation of caspase-3. These results suggest that both acute and chronic stress can potentially activate the intrinsic/extrinsic apoptosis pathways in testes. Chronic stress also reduces the quality of epididymal spermatozoa, possibly due to a decrease in testosterone.
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PMID:Intrinsic and extrinsic apoptotic pathways are involved in rat testis by cold water immersion-induced acute and chronic stress. 2586 67

The cellular prion protein PrPC is highly expressed in neurons, but also present in non-neuronal tissues, including the testicles and spermatozoa. Most immune cells and their bone marrow precursors also express PrPC. Clearly, this protein operates in highly diverse cellular contexts. Investigations into putative stress-protective roles for PrPC have resulted in an array of functions, such as inhibition of apoptosis, stimulation of anti-oxidant enzymes, scavenging roles, and a role in nuclear DNA repair. We have studied stress resilience of spermatozoa and peripheral blood mononuclear cells (PBMCs) derived from non-transgenic goats that lack PrPC (PRNPTer/Ter) compared with cells from normal (PRNP+/+) goats. Spermatozoa were analyzed for freeze tolerance, DNA integrity, viability, motility, ATP levels, and acrosome intactness at rest and after acute stress, induced by Cu2+ ions, as well as levels of reactive oxygen species (ROS) after exposure to FeSO4 and H2O2. Surprisingly, PrPC-negative spermatozoa reacted similarly to normal spermatozoa in all read-outs. Moreover, in vitro exposure of PBMCs to Doxorubicin, H2O2 and methyl methanesulfonate (MMS), revealed no effect of PrPC on cellular survival or global accumulation of DNA damage. Similar results were obtained with human neuroblastoma (SH-SY5Y) cell lines stably expressing varying levels of PrPC. RNA sequencing of PBMCs (n = 8 of PRNP+/+ and PRNPTer/Ter) showed that basal level expression of genes encoding DNA repair enzymes, ROS scavenging, and antioxidant enzymes were unaffected by the absence of PrPC. Data presented here questions the in vitro cytoprotective roles previously attributed to PrPC, although not excluding such functions in other cell types or tissues during inflammatory stress.
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PMID:Stress Resilience of Spermatozoa and Blood Mononuclear Cells without Prion Protein. 2941 49