scholarly journals Plasma and ovarian oestradiol and the variability in the LH surge induced in ewes by the ram effect

Reproduction ◽  
2015 ◽  
Vol 149 (5) ◽  
pp. 511-521 ◽  
Author(s):  
Claude Fabre-Nys ◽  
Audrey Chanvallon ◽  
Nathalie Debus ◽  
Dominique François ◽  
Frédéric Bouvier ◽  
...  

The proportion of anoestrous ewes ovulating after exposure to a sexually active ram is variable mainly due to whether an LH surge is induced. The aim of this study was to determine the role of oestradiol (E2) in the ram-induced LH surge. In one study, we measured the plasma concentrations of E2 in ewes of different breeds before and after the ‘ram effect’ and related these patterns to the presence and latency of the LH surge, while another compared ovarian responses with the ‘ram effect’ following exposure to rams for 2 or 12 h. In all ewes, the concentration of E2 increased 2–4 h after rams were introduced and remained elevated for 14.5±0.86 h. The quantity of E2 secreted before the LH surge varied among breeds as did the mean concentration of E2. The granulosa cells of IF ewes collected after 12 h exposure to rams secreted more E2 and progesterone and had higher levels of StAR than the 2 h group but in MV ewes there was no differences between these groups for any of these parameters. These results demonstrate that the LH surge induced by the rams is a result of increased E2 secretion associated with increased levels of STAR in granulosa cells and that these responses varied among breeds. The results suggest that the variable occurrence of a LH surge and ovulation may be the result of variable ovarian responses to the ‘ram effect’ and insensitivity of the hypothalamus to the E2-positive feedback signal.Free French abstract: A French translation of this abstract is freely available at http://www.reproduction-online.org/content/149/5/511/suppl/DC1.

1990 ◽  
Vol 69 (3) ◽  
pp. 880-884 ◽  
Author(s):  
G. L. Jones ◽  
C. G. Lane ◽  
P. M. O'Byrne

Airway hyperresponsiveness after inhaled ozone in dogs may occur as a result of thromboxane release in the airway. In this study, two thromboxane receptor antagonists, L-655,240 and L-670,596, were used in doses that inhibit the response to an inhaled thromboxane mimetic, U-46619, to determine further the role of thromboxane in ozone-induced airway hyperresponsiveness. Dogs were studied on 2 days separated by 1 wk. On each day, the dogs inhaled ozone (3 ppm) for 30 min. On one randomly assigned day, 10 dogs received an infusion of L-655,240 (5 mg.kg-1.h-1) and 5 dogs received an infusion of L-670,596 (1 mg.kg-1.h-1); on the other day dogs received a control infusion. Airway responses to doubling doses of acetylcholine were measured before and after inhalation of ozone and were expressed as the concentration of acetylcholine giving a rise in resistance of 5 cmH2O.l-1.s from baseline (acetylcholine provocation concentration). The development of airway hyperresponsiveness after ozone was not inhibited by the thromboxane antagonists. The mean log difference in the acetylcholine provocative concentration before and after ozone on the L-655,240 treatment day was 0.62 +/- 0.12 (SE) and on the control day was 0.71 +/- 0.12 (P = 0.48); on the L-670,596 treatment day the mean log difference was 0.68 +/- 0.15 (SE) and on the control day it was 0.75 +/- 0.19 (P = 0.45). These results do not support an important role for thromboxane in causing ozone-induced airway hyperresponsiveness.


1990 ◽  
Vol 127 (3) ◽  
pp. 461-469 ◽  
Author(s):  
E. Ssewannyana ◽  
G. A. Lincoln

ABSTRACT In a group of adult Soay rams housed indoors under an artificial light cycle of alternating 16-week periods of long and short days, there was a conspicuous longterm cycle in the peripheral plasma concentrations of β-endorphin and prolactin. The levels of β-endorphin were highest under short days and lowest under long days (15-fold change), and inversely related to the changes in the plasma levels of prolactin (120-fold change). The role of dopamine in the control of β-endorphin and prolactin was investigated in a series of experiments, conducted under both long and short days, in which rams were treated with dopamine receptor agonists (dopamine and bromocriptine) and antagonists (pimozide and sulpiride). Naloxone (opioid antagonist) was also administered to assess the additional involvement of endogenous opioids. Dopamine injected i.v. (6·6 mg/kg every 10 min) did not significantly affect the mean plasma concentrations of β-endorphin and prolactin under either long or short days. Pimozide (0·08 mg/kg i.m. every 2 h) caused a large increase in the mean plasma concentrations of β-endorphin and prolactin under long days but not short days. Naloxone (1·6 mg/kg, i.v.), administered alone or in combination with dopamine or pimozide, had no effect on the mean plasma concentrations of β-endorphin and prolactin, except under short days when, combined with pimozide, it induced an increase in the plasma concentrations of the two polypeptides. Bromocriptine (0·06 mg/kg, s.c.) caused a significant decrease in the plasma concentrations of both β-endorphin and prolactin; this effect was most marked at the times of increased secretion (under short days for β-endorphin and under long days for prolactin). Sulpiride (0·59 mg/kg, s.c.) produced the converse effect and caused an increase in the plasma concentrations of β-endorphin and prolactin with the amplitude and duration of the effect varying with the stage of the photoperiod-induced cycle. From these results in the Soay ram, we conclude that dopamine inhibits β-endorphin and prolactin secretion by way of D2 receptors under both long and short days. Endogenous opioids interact with dopamine, augmenting this inhibition under short days. Differences in the acute responses in the secretion of β-endorphin and prolactin, and the inverse relationship between β-endorphin and prolactin during the cycle, indicate that different regulatory systems involving dopamine influence the two pituitary polypeptides. Journal of Endocrinology (1990) 127, 461–469


QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Ali Abdulkareem Al-Shabkhon ◽  
Adel Ahmed Halim Emam ◽  
Ahmed Abd Elfattah Afify

Abstract Background Immunologic background of vitiligo, role of vitamin D on its pathogenesis, role of NB-UVB on its treatment and its stimulatory effect NB-UVB on VDR expression are challenging area of research. The current study will focus on evaluating the effect of NB-UVB on serum and tissue level of vitamin D in vitiligo patients and correlating it with the degree of improvement. Aim of the study The aim of the present study is to evaluate and compare the serum and tissue vitamin D level in vitiligo patients before and after NB- UVB therapy and correlate them together and with the degree of improvement. Patients and methods A case-control study included 16 vitiligo patients and 16 age and sex matched healthy controls. All patients will be examined by one dermatologist (demonstrating the extent of depigmentation according to rule of nines), and photographs will be taken before and after phototherapy to be evaluated by two different dermatologists to document the extent of repigmentation. Estimation of serum level of vitamin D by ELISA Results Five of the 15 patients achieved more than 55% repigmentation; the mean duration of disease was 13 months. The remaining 10 patients had 30% - 40% repigmentation.


2010 ◽  
Vol 10 ◽  
pp. 742-759 ◽  
Author(s):  
Hang Thi Nguyen ◽  
Chan Goo Park ◽  
Jin-A Kim ◽  
Je-Seung Lee ◽  
Jin-Hong Lee ◽  
...  

Concentrations of 17 trace metals bound in total suspended particulate (TSP) were measured at four urban residential locations (Jong Ro [JR], Gwang Jin [GJ], Gang Seo [GS], and Yang Jae [YJ]) in Seoul, Korea from February to July 2009. The maximum concentrations of metals were recorded by Fe in the range of 2599 (JR) to 2914 ng m-3(GJ), while the least values were observed from Ag or Co with a few ng m-3. The relative ordering of the mean concentration (ng m-3) at these sites is generally found on the order of Fe > Zn > Ba > Mn > Pb > Cu > B > Cr > Ni > Sr >V > As > Li > Cd > Mo > Co > Ag or with a few exceptions (e.g., a reversal between Ba and Mn or between Ni and Sr). Calculation of the enrichment factor suggests the significant role of man-made processes on such metals as Cd, Zn, and Pb. Inspection of the temporal patterns indicates the peak occurrence of most metals during the spring season due in part to the Asian Dust (AD) event. However, according to the factor analysis, sources of these metals were dominated by both resuspended soil/road dust and the combustion of fossil fuels. The overall results of our study suggest that the interaction between the environmental conditions and roadside traffic activities are paramount in explaining the metal pollution in these urban residential areas.


1984 ◽  
Vol 247 (1) ◽  
pp. R208-R211
Author(s):  
S. Yoneda ◽  
N. Alexander ◽  
N. D. Vlachakis ◽  
R. F. Maronde

Plasma and red blood cell (RBC) concentrations of normetanephrine (NMN), in both free and glucuronide-conjugated forms, were measured before, during, and after forced immobilization, an intense stressor of the sympathoadrenal system of rats. In this study NMN glucuronide was deconjugated by enzymatic hydrolysis; free and total NMN were assayed by radioenzymatic, thin-layer chromatographic procedures. In plasma, free NMN and NMN glucuronide are 777 +/- 99 and 792 +/- 74 pg/ml, respectively, when rats are at rest. Both free NMN and NMN glucuronide increased about 200% after 15 min of stress; in absolute amounts, increases were equivalent to that of the simultaneous increase in norepinephrine (NE). At 2 h of stress, NMN glucuronide, but not free NMN, increased further and significantly. The mean concentration of RBC-free NMN is about 50 times higher than that of plasma-free NMN, and it did not change significantly during stress; RBCs do not contain conjugated NMN. RBC NMN levels showed a strong correlation with RBC catechol methyltransferase activity. The latter seems to operate under conditions of substrate saturation; an acute release of NE leads to temporary storage of NE in RBCs but not conversion to NMN. The results indicate that conjugation of NMN with glucuronic acid is an important route for inactivation of plasma NMN formed during forced immobilization stress, whereas free NMN does not accumulate in RBCs during stress.


1975 ◽  
Vol 21 (4) ◽  
pp. 521-527 ◽  
Author(s):  
Noritake Asato ◽  
Maria van Soestbergen ◽  
F William Sunderman

Abstract Binding of 63Ni(Il) to ultrafiltrable constituents of rabbit serum was studied (a) after in vitro incubation (2 h, 37 °C) of rabbit serum with 63NiCl2 (10-100 µmol/liter), and (b) at intervals (0.25-2 h) after in vivo administration of 63NiCl2 (40-160 µmol/kg body wt, i.v.). Serum ultrafiltrates were fractionated by thin-layer chromatography, and the separated compounds made visible by autoradiography and by ninhydrin staining. Several (≃5) ultrafiltrable 63Ni-complexes were demonstrable as distinct radiodense 63Ni-bands with chromatographic mobilities corresponding to those of ninhydrin-positive bands. Unbound 63Ni(II) was not detected in serum ultrafiltrates in either the in vitro or in vivo experiments. In sera (n = 10) incubated in vitro with 63Ni(II) (10 µmol/ liter), the mean percentage of ultrafiltrable 63Ni was 36% (range = 33-38) of total serum 63Ni. In contrast, in sera (n = 10) obtained 2 h after i.v. injection of 63Ni(II) (40 µmol/kg), the mean concentration of total serum 63Ni was 10.8 µmol/liter (range = 6-14), and the mean percentage of ultrafiltrable 63Ni was 15% (range = 9-21) of total serum 63Ni. The disparity between the percentages of ultrafiltrable 63Ni obtained in vitro and in vivo was obviated when the in vivo experiments were performed in rabbits bilaterally nephrectomized, with ligated common bile ducts. This investigation confirms the existence of several nickel receptors in serum ultrafiltrates and substantiates the role of ultrafiltrable complexes in the excretion of nickel.


1981 ◽  
Vol 61 (6) ◽  
pp. 781-784 ◽  
Author(s):  
J. Savoy ◽  
S. Dhingra ◽  
N. R. Anthonisen

1. in 10 patients with pulmonary fibrosis and in seven control subjects, we measured the pressure at the mouth 0.1 s after onset of an inspiration against occluded airway (P0.1), minute ventilation (VI), breathing frequency (fr), tidal volume (VT), inspiratory duration (Tl) and calculated the mean inspiratory flow (VT/Tl) and the fraction of the breath cycle devoted to inspiration (Tl/Ttot.). in the patients measurements were made at normal arterial oxygen saturations (Sao2), before and after lignocaine airway anaesthesia. 2. Efficacy of airway anaesthesia was tested by the cough response to citric acid inhalation. 3. in pulmonary fibrosis P0.1, f1 and VT/Tl were greater than in the control subjects, VT and Tl, were smaller and Tl/Ttot. and VI were not different. 4. Effective airway anaesthesia did not modify P0.1 and breathing pattern parameters observed in pulmonary fibrosis. 5. These results suggest that airway receptors do not contribute to a major extent to the control of breathing in pulmonary fibrosis.


Cephalalgia ◽  
2006 ◽  
Vol 26 (11) ◽  
pp. 1287-1293 ◽  
Author(s):  
M Alessandri ◽  
L Massanti ◽  
P Geppetti ◽  
G Bellucci ◽  
M Cipriani ◽  
...  

Little is known of mechanism of dialysis headache (DH). As suggested for migraine, a role for neuropeptides has been investigated. Twenty-four patients under haemodialysis were studied. Twelve of them suffered from DH. The remaining patients were headache free. Blood samples for radioimmunoassay of calcitonin gene-related peptide (CGRP) and substance P (SP) were collected from the arteriovenous fistula before and after dialysis treatment. Basal plasma concentrations of CGRP were found to be higher in headache patients. Dialysis significantly decreased CGRP concentrations in both groups. No difference in basal plasma concentrations of SP was observed between groups. At the end of the treatment plasma SP concentrations were reduced in headache-free patients but increased in headache patients. Elevated plasma concentrations of CGRP in patients with DH could represent a biochemical factor contributing to susceptibility to headache. Because of the disputable role of SP in migraine, the significance of the increase of the peptide in plasma during DH remains to be elucidated.


1981 ◽  
Vol 15 (12) ◽  
pp. 993-996 ◽  
Author(s):  
Robert L. Talbert ◽  
Yan Yan Wong ◽  
Douglas B. Duncan

Propranolol plasma concentrations were determined in a patient with hemolytic-uremic syndrome undergoing plasmapheresis before and after the procedure on three occasions. The mean half-life and elimination rate constant during plasmapheresis were estimated to be 25.6 percent of the values obtained without plasmapheresis. These changes suggest that plasmapheresis may influence propranolol disposition.


2015 ◽  
Vol 173 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Aleksandr Peet ◽  
Anu-Maaria Hämäläinen ◽  
Pille Kool ◽  
Jorma Ilonen ◽  
Mikael Knip ◽  
...  

ObjectiveThis study aimed at investigating the role of IGF1 and IGF binding protein 3 (IGFBP3) in the development of β-cell autoimmunity.MethodsFive hundred and sixty-three subjects with HLA-conferred susceptibility to type 1 diabetes (T1D) were monitored for signs of seroconversion to positivity for insulin and/or GAD, IA2, and zinc transporter 8 autoantibodies by the age of 3 years. In 40 subjects who developed at least one autoantibody, IGF1 and IGFBP3 plasma concentrations were measured and compared with 80 control subjects who remained negative for autoantibodies, and were matched for age, sex, country of origin, and HLA genotype. The increments of IGF1, IGFBP3, and IGF1/IGFBP3 molar ratio before and after seroconverison were compared with corresponding time intervals in controls.ResultsThe IGF1 concentrations at the age of 12 months and the IGF1/IGFBP3 ratio at the age of 24 months were lower in the autoantibody-positive children (P<0.05). The increase in circulating IGFBP3 was significantly higher in the autoantibody-positive children before seroconversion than in the corresponding time intervals in controls (0.43 mg/l; 95% CI 0.29–0.56 vs 0.22 mg/l; 95% CI 0.10–0.34 mg/l; P<0.01). Children carrying the high-risk HLA genotype had lower plasma IGF1 and IGFBP3 concentrations at the age of 24 months than those with low-risk genotypes (P<0.05 and < 0.01 respectively).ConclusionsCirculating IGF1 and IGFBP3 appear to have a role in early development of β-cell autoimmunity. The decreased IGF1 concentrations in children with the high-risk HLA genotype may contribute to the reduced growth previously described in such children.


Sign in / Sign up

Export Citation Format

Share Document