scholarly journals Preliminary results of toxicity studies in rats following low-dose and short-term exposure to methyl mercaptan

2019 ◽  
Vol 6 ◽  
pp. 431-438 ◽  
Author(s):  
Jingjing Fang ◽  
Xinhong Xu ◽  
Lu Jiang ◽  
Jiangbo Qiao ◽  
Hongyuan Zhou ◽  
...  
Keyword(s):  
Low Dose ◽  
Methyl Mercaptan ◽  
Short Term ◽  
Preliminary Results ◽  
Toxicity Studies ◽  
Short Term Exposure

Neuroimmunological Effects of Exposure to Methylmercury Forms in the Sprague-Dawley Rats. Activation of the Hypothalamic-Pituitary-Adrenal Axis and Lymphocyte Responsiveness

1997 ◽  
Vol 13 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Hector G. Ortega ◽  
Manuel Lopez ◽  
Atsushi Takaki ◽  
Qin-Heng Huang ◽  
Akira Arimura ◽  
...  
Keyword(s):  
Hpa Axis ◽  
Low Dose ◽  
Fold Increase ◽  
Exposed Group ◽  
Blood Levels ◽  
High Dose ◽  
Sprague Dawley ◽  
Short Term ◽  
Hypothalamic Pituitary Adrenal ◽  
Short Term Exposure

The effects of different methylmercury (MeHg) forms on the immune system and the hypothalamic pituitary adrenal (HPA) axis were assessed. The lymphocyte response to Concanavalin A (Con A) stimulation, blood levels of interleukin-6 (IL-6), adrenocorticotrophin hormone (ACTH), and corticosterone in the presence of different MeHg compounds was measured. Rats were exposed to methylmercury sulfide [(MeHg)2S] and methylmercury chloride (MeHgCl) at concentrations of 5 and 500 μg per liter in the drinking water for 8 or 16 weeks. Short-term exposure (8 weeks) at both, low- and high-doses of (MeHg)2S significantly enhanced lymphocyte responsiveness. MeHgCl only induced increased lymphocyte responsiveness at the low-dose exposure. Circulating levels of IL-6 after short-term exposure were increased in the MeHgCl-exposed group. The HPA axis activation was demonstrated by increased levels of ACTH and corticosterone levels. This response was predominant in low-dose exposed animals. Long-term (16 weeks) exposure resulted in a reduction in lymphocyte proliferation after both low- and high-dose MeHgCl exposures. The (MeHg)2S exposure resulted in a 3-fold increase in the proliferative response. Levels of ACTH were elevated 3-fold in the (MeHg)2S-exposed group, and no increase of corticosterone was observed in the high-dose exposed group at 8 weeks, no effect of(MeHg)2S was observed at 16 weeks. The MeHgCl exposed group showed an increase in ACTH and corticosterone levels at 8 weeks; this response was not observed at 16 weeks. These data indicate that exposure to MeHg compounds enhances T-cell proliferation in most of the cases, in a dose- and time-dependent fashion. Release of IL-6 also depends on the length of exposure. Early increases in circulating ACTH at 8 weeks also suggest activation of the HPA axis. This may contribute to the production of IL-6 and surveillance of regulatory homeostatic responses against environmental agents that mimic stress-like responses.

scholarly journals Hormone-Like Effects of 4-Vinylcyclohexene Diepoxide on Follicular Development

2020 ◽  
Vol 8 ◽  
Author(s):  
Lian Bao Cao ◽  
Hong Bin Liu ◽  
Gang Lu ◽  
Yue Lv ◽  
Chi Kwan Leung ◽  
...  
Keyword(s):  
Ovarian Reserve ◽  
Low Dose ◽  
Follicular Development ◽  
Primordial Follicle ◽  
High Dose ◽  
Short Term ◽  
Primary Follicle ◽  
Vinylcyclohexene Diepoxide ◽  
Short Term Exposure

Background4-vinylcyclohexene diepoxide (VCD) has long been considered a hazardous occupational chemical that promotes ovarian failure. However, VCD is also used as a research compound to chemically induce animal models of premature ovarian insufficiency (POI), and in related work we unexpectedly found that VCD apparently exhibits both dose- and duration-dependent opposing, hormone-like effects on the maintenance of the primordial follicle pool, follicle development, and ovulation induction.ResultsWe conducted experiments with cultured murine ovaries and performed transplantation experiments using postnatal day (PD) 2 and PD12 mice and found that low-dose, short-term exposure to VCD (VCDlow) actually protects the primordial/primary follicle pool and improves the functional ovarian reserve (FOR) by disrupting follicular atresia. VCDlow inhibits follicular apoptosis and regulates the Pten-PI3K-Foxo3a pathway. Short-term VCD exposure in vivo (80 mg/kg, 5 days) significantly increases the number of superovulated metaphase II oocytes, preovulatory follicles, and corpus luteum in middle-aged mice with diminished ovarian reserve (DOR). We demonstrate that low-dose but not high-dose VCD promotes aromatase levels in granulosa cells (GCs), thereby enhancing the levels of estradiol secretion.ConclusionOur study illustrates a previously unappreciated, hormone-like action for the occupational “ovotoxin” molecule VCD and strongly suggests that VCDlow should be explored for its potential utility for treating human ovarian follicular development disorders, including subfertility in perimenopausal women.

scholarly journals Deoxynivalenol Impairs Weight Gain and Affects Markers of Gut Health after Low-Dose, Short-Term Exposure of Growing Pigs

Toxins ◽  
2015 ◽  
Vol 7 (6) ◽  
pp. 2071-2095 ◽  
Author(s):  
Arash Alizadeh ◽  
Saskia Braber ◽  
Peyman Akbari ◽  
Johan Garssen ◽  
Johanna Fink-Gremmels
Keyword(s):  
Weight Gain ◽  
Low Dose ◽  
Growing Pigs ◽  
Gut Health ◽  
Short Term ◽  
Short Term Exposure

Short-Term Exposure to Low-Dose Ritonavir Impairs Clearance and Enhances Adverse Effects of Trazodone

2003 ◽  
Vol 43 (4) ◽  
pp. 414-422 ◽  
Author(s):  
David J. Greenblatt ◽  
Lisa L. von Moltke ◽  
Jerold S. Harmatz ◽  
Steven M. Fogelman ◽  
Gengsheng Chen ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Low Dose ◽  
Short Term ◽  
Short Term Exposure

The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Dimethyl Sulfoxide ◽  
Platelet Function ◽  
Platelet Volume ◽  
Short Term ◽  
Platelet Factor ◽  
Short Term Exposure ◽  
Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

Short-term, low-dose ACTH therapy in West syndrome

2005 ◽  
Vol 36 (02) ◽  
Author(s):  
G Ramantani ◽  
M Tzitiridou ◽  
C Panteliadis
Keyword(s):  
Low Dose ◽  
West Syndrome ◽  
Short Term ◽  
Acth Therapy
Sign in / Sign up

Export Citation Format

Share Document