Reduction in oocyte production and gonadotrope activity, and plasma levels of estrogens and vitellogenin, in brook trout exposed to low environmental pH

1990 ◽  
Vol 68 (12) ◽  
pp. 2468-2476 ◽  
Author(s):  
W. H. Tam ◽  
J. N. Fryer ◽  
B. Valentine ◽  
R. J. J. Roy
Keyword(s):  
Plasma Levels ◽  
Brook Trout ◽  
Acid Stress ◽  
Secretory Activity ◽  
Experimental Period ◽  
Acid Exposure ◽  
Control Fish ◽  
Cortisol Secretion ◽  
Control Value ◽  
The Mean

Maturing brook trout were exposed to pH 4.5 at the beginning of the rapid oocyte development phase in mid-June. The number of atretic follicles containing vitellogenic oocytes in acid-treated trout gradually increased with time, to exceed that of control fish on day 30, reaching a maximum (22–24% of all vitellogenic oocytes) between days 45 and 60 of acid exposure, before declining on day 73. Follicular atresia reduced the number of healthy vitellogenic oocytes in the acid-stressed fish to 59% of controls by day 60. Plasma vitellogenin and estrogen levels were not consistently affected by acid exposure. During the first 45 days of acid exposure, the mean weight of the healthy vitellogenic oocytes and the plasma levels of estrogen in the acid-exposed fish were at times significantly higher than those of control trout, but after day 45 these differences were no longer observed. Ultrastructural morphometry showed that secretory activity of the gonadotropes in the female acid-stressed brook trout was suppressed. Throughout the experimental period, the acid-exposed trout showed various symptoms characteristic of acid stress, such as elevated ACTH and cortisol secretion, hyperglycemia, acidosis, and hyponatremia. Food intake was reduced to 14% of the control value. These results suggest that the disruptive physiological changes and (or) reduced nutritional status associated with acid stress are responsible for the reduction in activity of the gonadotropes and oocyte atresia.

Effects of Chronic Exposure to Sublethal pH on Growth, Egg Production, and Ovulation in Brook Trout, Salvelinus fontinalis

1986 ◽  
Vol 43 (2) ◽  
pp. 275-280 ◽  
Author(s):  
W. H. Tam ◽  
P. D. Payson
Keyword(s):  
Brook Trout ◽  
Egg Production ◽  
Salvelinus Fontinalis ◽  
Experimental Period ◽  
The Body ◽  
Oocyte Development ◽  
Control Fish ◽  
Ph Values ◽  
Body Weights ◽  
The Mean

Hatchery-reared brook trout (Salvelinus fontinalis) were maintained in the laboratory at mean pH values of 7.34, 5.56, 5.16, and 4.48 from early February to early December. At pH 4.48, the mean growth rates of males were uniformly lowered during the entire experimental period. Among females, growth was inhibited during the first 5 mo, but their rate of weight gain recovered during the period of rapid oocyte development. At the end of the experiment, the body weights of both male and female fish in pH 5.16 and 4.48 were only 70.70–77.34% of the control fish at pH 7.34. Growth was not affected by exposure to pH 5.56. Rapid oocyte development occurred simultaneously over all pH groups in June, suggesting that the initiation of gametogenesis was not affected over the range of pH tested, the number of eggs produced was significantly correlated to body weight; consequently the number of eggs produced by the smaller pH 5.16–4.48 females was reduced. Ovulation was also significantly delayed in the acidic groups.

Covariation in regulation of affinity for branchial zinc and calcium uptake in freshwater rainbow trout.

1998 ◽  
Vol 201 (11) ◽  
pp. 1809-1815 ◽  
Author(s):  
C Hogstrand ◽  
N Webb ◽  
C M Wood
Keyword(s):  
Rainbow Trout ◽  
Fold Increase ◽  
Experimental Period ◽  
Competitive Inhibitor ◽  
Control Fish ◽  
Control Value ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Significant Linear Correlation ◽  
Ca Uptake ◽  
Transport Site

The possible coupling between regulation of the affinities for branchial Zn and Ca influx was investigated in juvenile rainbow trout Oncorhynchus mykiss acclimated to relatively hard fresh water ([Ca]=1.0 mmol l-1). The Km for branchial Ca influx was manipulated experimentally by exposing the fish to 2.3 micromol l-1 waterborne Zn for a total of 28 days. This procedure resulted in rapidly increased Km values for both Ca and Zn influx, an effect that remained through the experimental period. There was a significant linear correlation (r=0.88, P<0.02) between Km values for Ca and Zn measured at the same time points. Zn exposure caused progressively increasing maximum rate of transport, Jmax, values for Zn relative to the control value, but there was little, if any, effect on Jmax for Ca. These results support the idea of a shared transport site for Zn and Ca at the apical membrane of the gill epithelium and suggest that there is a certain degree of coregulation of branchial Zn and Ca uptake in rainbow trout. Removal of Ca from the water resulted in a large (six- to 24-fold) increase in affinity (decreased Km) for Zn influx and a modest (1.1- to 1.8-fold) increase in Jmax for Zn. Thus, Ca is a competitive inhibitor of Zn influx. In water lacking Ca, the Km for Zn in Zn-acclimated fish was no different from that of the control fish, suggesting that the Ca2+/Zn2+ transporter was regulated to improve Ca uptake.

Modification of Carbohydrate Metabolism and Liver Vitellogenic Function in Brook Trout (Salvelinus fontinalis) by Exposure to Low pH

1987 ◽  
Vol 44 (3) ◽  
pp. 630-635 ◽  
Author(s):  
W. H. Tam ◽  
L. Birkett ◽  
R. Makaran ◽  
P. D. Payson ◽  
D. K. Whitney ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Acid Stress ◽  
Somatic Growth ◽  
Liver Weight ◽  
Liver Glycogen ◽  
Control Fish ◽  
Glucose Levels ◽  
Blood Glucose Levels

Brook trout (Salvelinus fontinalis), 1+ yr old, were exposed to pH 4.48 from February to December. Compared with control fish maintained at pH 7.34, acid-stressed fish generally had elevated blood glucose levels. Plasma cortisol concentration, measured only in males, was significantly increased in the acid-treated trout up to July. Although somatic growth decreased by about 30% by the end of the experiment, peritoneal fat was unchanged. During the reproductive season, female plasma levels of oestrogen and vitellogenin were the same at both pH levels. When immature fish were implanted with oestradiol-17β and then maintained for 21 d either in pH 7.34 (control) or 4.48, acid-treated fish again showed increased blood glucose levels. Liver weight increased at both pH levels, but liver glycogen was depleted and plasma vitellogenin was significantly increased by exogenous oesterogen only in control fish. It is postulated that before acclimation occurs, acid stress increases cortisol secretion, diverts nutrients normally used for growth to maintain a high blood sugar level, and affects the liver's ability to metabolize carbohydrates and synthesize vitellogenin.

Growth Inhibition, Gluconeogenesis, and Morphometric Studies of the Pituitary and Interrenal Cells of Acid-Stressed Brook Trout (Salvelinus fontinalis)

1988 ◽  
Vol 45 (7) ◽  
pp. 1197-1211 ◽  
Author(s):  
W. H. Tam ◽  
J. N. Fryer ◽  
I. Ali ◽  
M. R. Dallaire ◽  
B. Valentine
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Hormone Secretion ◽  
Acid Stress ◽  
Somatic Growth ◽  
Experimental Period ◽  
Plasma Cortisol Level ◽  
Electron Microscopic ◽  
Cell Hyperplasia ◽  
Plasma Protein Concentration

Somatic growth was stunted in yearling brook trout (Salvelinus fontinalis) maintained for up to 73 d in pH 4.5. Plasma cortisol level increased in pulses after 1.5 h (from 10 to 82.3 ng∙mL−1) on days 4 (46 ng∙mL−1) and 15–30 (20–25 ng∙mL−1) of acid treatment. Interrenal nuclear hypertrophy and cell hyperplasia occurred respectively on days 4 and 15. Electron microscopic observations revealed that the somatotropes and thyrotropes were atrophic for about half of the experimental period whereas the corticotropes displayed sustained hypertrophy. Plasma glucose and amino acid levels rose simultaneously by 300–600 and 130%, respectively, from day 4 of acid exposure. Hepatic L-alanine aminotransferase activity increased on day 30 just as plasma protein concentration began to decline. When adrenalin and cortisol acetate were administered to trout maintained in neutral pH to raise circulating cortisol levels from 10–20 to 1876 ng∙mL−1, blood glucose remained normal up to 6 d after treatment. These results suggested that acid stress suppressed somatotropin, thyrotropin, and indirectly thyroid hormone secretion but stimulated the pituitary–interrenal axis, leading to inhibition of protein synthesis and accumulation of amino acids in the circulation. The elevation of blood sugar level was caused by some as yet unidentified factors.

Plasma Thrombospondin as an Indicator of Intravascular Platelet Activation in Patients with Vasculitis

1987 ◽  
Vol 58 (03) ◽  
pp. 850-852 ◽  
Author(s):  
M B McCrohan ◽  
S W Huang ◽  
J W Sleasman ◽  
P A Klein ◽  
K J Kao
Keyword(s):  
Platelet Activation ◽  
Plasma Levels ◽  
Half Life ◽  
Degradation Products ◽  
Plasma Concentrations ◽  
Primary Source ◽  
Positive Correlation ◽  
Activation Marker ◽  
Fibrin Degradation Products ◽  
The Mean

SummaryThe use of plasma thrombospondin (TSP) concentration was investigated as an indicator of intravascular platelet activation. Patients (n = 20) with diseases that have known vasculitis were included in the study. The range and the mean of plasma TSP concentrations of patients with vasculitis were 117 ng/ml to 6500 ng/ml and 791±1412 ng/ml (mean ± SD); the range and the mean of plasma TSP concentrations of control individuals (n = 33) were 13 ng/ml to 137 ng/ml and 59±29 ng/ml. When plasma TSP concentrations were correlated with plasma concentrations of another platelet activation marker, β-thromboglobulin (P-TG), it was found that the TSP concentration inei eased exponentially as the plasma β-TG level rose. A positive correlation between plasma levels of plasma TSP and serum fibrin degradation products was also observed. The results suggest that platelets are the primary source of plasma TSP in patients with various vasculitis and that plasma TSP can be a better indicator than β-TG to assess intravascular platelet activation due to its longer circulation half life.

EFFECT OF OESTRONE-PELLET IMPLANTATION ON PLASMA LEVELS OF PROLACTIN

1970 ◽  
Vol 64 (2) ◽  
pp. 265-272 ◽  
Author(s):  
A. A. van der Gugten ◽  
M. Sala ◽  
H. G. Kwa
Keyword(s):  
Plasma Levels ◽  
Male Rats ◽  
Mean Values ◽  
The Mean ◽  
Dose Levels ◽  
Higher Doses ◽  
Primary Break

ABSTRACT Eight female and eight male rats were castrated at the age of 8 to 10 weeks. Four spayed and four orchidectomized rats received one oestrone/cholesterol pellet (200 μg oestrone) on the day of operation (day 0), a second pellet on day 11 and a third on day 23. The remaining animals received four oestrone/cholesterol pellets at these times. The fluctuations in the prolactin levels in the circulation induced by the oestrogen challenges in these animals were followed during 31 days by radioimmunoassays performed on days 3, 7, 9, 14, 15, 17, 23, 24, 25, 28 and 31. The results suggested that the homoeostatic mechanism regulating plasma levels of prolactin was capable of withstanding the three time-spaced oestrogen challenges only in the spayed animals receiving the lower doses of oestrogen, since it allowed the mean values of the prolactin levels to remain fairly constant during the first 4 weeks. The levels in this group rose to much higher levels only on day 31. The higher doses of oestrone in the spayed rats and both dose levels of oestrone in the orchidectomized animals apparently resulted in a primary break-down of the homoeostatic mechanism, since the prolactin levels in the animals of these groups rose to much higher levels either on day 7 or on day 9. This was followed by a period during which the prolactin levels appeared to be more or less under control, until a second and probably definitive failure of the homoeostatic mechanism allowed the mean levels to rise sharply again.

Pharmacodynamics of [D-Ser (t-Bu), Des-Gly]GnRH ethylamide (Buserelin®) in 6 normal volunteers.

1987 ◽  
Vol 115 (2) ◽  
pp. 235-242 ◽  
Author(s):  
Y. Reznik ◽  
B. P. Winiger ◽  
M. L. Aubert ◽  
P. C. Sizonenko
Keyword(s):  
Urinary Excretion ◽  
Precocious Puberty ◽  
Plasma Levels ◽  
Intranasal Administration ◽  
Cross Reaction ◽  
Disappearance Rate ◽  
Gnrh Analog ◽  
Male Adolescents ◽  
Normal Volunteers ◽  
The Mean

Abstract. The disappearance rate of [D-Ser(t-bu)6,des-Gly10]GnRH ethylamide (Buserelin®, HOE 766) was studied in plasma and urine after intranasal (300 μg) or sc (10 μg/kg) administration. A radioimmunoassay for HOE 766 was developed using 125I[D-Trp6,Des-Gly10]GnRH ethylamide as tracer and an antiserum raised against HOE 766. Cross-reaction with native GnRH was only 1.7%. Sensitivity was 1 pg/tube. In 6 male adolescents, the mean plasma HOE 766 concentration (± sem) was 0.46 ± 0.08, 0.50 ± 0.10, 0.28 ± 0.04, 0.24 ± 0.04, 0.13 ± 0.03, and 0.08 ± 0.02 μg/l 30, 60, 90, 120 and 180 min after the intranasal administration, respectively. Concomitant urinary excretion of HOE 766-like material was 9.43 ± 1.96 μg/4 h. There was a good correlation between integrated plasma levels and urinary excretion (r = 0.92). In the same 6 volunteers, the plasma HOE 766 levels were 21.2 ± 3.0, 25.9 ± 0.8, 21.2 ± 0.9, 17.1 ± 0.7, 12.8 ± 1.1, 8.9 ± 0.4, and 5.9 ± 0.8 μg/l 20, 40, 60, 90, 120, 180 and 240 min after sc injection, respectively. The mean urinary excretion was 543 ± 61 μg/4 h. In two girls with precocious puberty treated during 12 to 15 months with intranasal administration of HOE 766, urinary excretion of HOE 766-like material was shown to correlate well with the degree of inhibition of plasma 17β-E2and of plasma LH and FSH responses to a GnRH challenge. Thus, monitoring of HOE 766 in urine appears to be helpful for evaluating of intranasal therapy with a GnRH analog in precocious puberty.

Effect of High Plane of Nutrition on Blood Biochemical Profile and Onset of Puberty in Prepubertal HF X Kankrej Crossbred Heifers

2019 ◽  
Vol 15 (02) ◽  
pp. 14-17
Author(s):  
K K Hadiya ◽  
A J Dhami ◽  
D V Chaudhari ◽  
P M Lunagariya
Keyword(s):  
Body Weight ◽  
Treatment Group ◽  
Plasma Levels ◽  
Age Of Onset ◽  
The Body ◽  
Monthly Interval ◽  
Control Group ◽  
Blood Biochemical ◽  
Lower Protein ◽  
The Mean

This study was initiated on 24 prepubertal Holstein x Kankrej crossbred heifers of nearly identical age (7-9 months) and body weight (130-140 kg) at University farm to evaluate the effect of high plane of nutrition on blood biochemical and minerals profile and the age at puberty. Twelve heifers were managed under routine farm feeding (control) and the rest 12 under ideal optimum feeding regime (treatment) that included extra 1 kg concentrate, 30 g min mix and ad-lib dry fodder. The body weight and ovarian ultrasonography together with blood sampling was carried out at monthly interval from 10 to 18 months of age to study the ovarian dynamics and blood biochemical changes. High plane of nutrition to growing heifers was beneficial in reducing the age of onset of puberty (by 2-3 months) compared to routine farm fed group. The mean plasma total protein and cholesterol concentrations showed a rising trend with significant variations from 10 to 16 months of age, where it got mostly stabilized indicating adult profile. The activity of enzymes GOT and GPT also rose gradually and significantly from 10 months till 14-15 months of age, and thereafter it remained more or less static till 18 months of age. The levels of both these enzymes were higher, with lower protein and cholesterol, in control than the treatment group from 15-16 months of age onwards. The mean plasma levels of both calcium and phosphorus increased gradually and significantly with advancing age till 16-17 months of age, with little higher values in supplemented than a control group. The plasma levels of zinc, iron, copper, and cobalt also showed rising trend with significant differences between 10th and 12th-14th months of age, and from 15th to 18th months of age the levels were statistically the same in all the groups with slightly higher values in the treatment group.

Increased plasma kynurenine and its relationship to neopterin and tryptophan in Tourette's syndrome

1996 ◽  
Vol 26 (4) ◽  
pp. 857-862 ◽  
Author(s):  
H. Rickards ◽  
S. M. Dursun ◽  
G. Farrar ◽  
T. Betts ◽  
J. A. Corbett ◽  
...  
Keyword(s):  
Tourette Syndrome ◽  
Negative Correlation ◽  
Plasma Levels ◽  
Significant Positive Correlation ◽  
Significant Negative Correlation ◽  
Healthy Controls ◽  
Positive Correlation ◽  
Control Value ◽  
Cellular Immune ◽  
Patient Value

SynopsisFasting plasma levels of tryptophan, kynurenine and the pteridines, neopterin and tetrahydrobiopterin were measured in seven patients with Gilles de la Tourette syndrome (GTS) and 10 healthy controls. Plasma kynurenine was significantly elevated in the GTS patients. The lowest patient value was higher than the highest control value. Values for tryptophan, neopterin and tetrahydrobiopterin were similar in TS patients and controls. However, in TS patients only, there was a significant negative correlation between tryptophan and neopterin and a significant positive correlation between kynurenine and neopterin when controlling for tryptophan. This finding indicates that activation of cellular immune processes is a possible explanation for the rise in plasma kynurenine.

THE EFFECT OF EXOGENOUS PROGESTAGEN ON THE LEVELS OF FREE OESTROGEN IN THE OVARIAN VEIN PLASMA OF THE EWE

1970 ◽  
Vol 48 (4) ◽  
pp. 485-496 ◽  
Author(s):  
J. F. SMITH ◽  
T. J. ROBINSON
Keyword(s):  
Plasma Levels ◽  
Similar Pattern ◽  
Peak Level ◽  
The Other ◽  
Ovarian Vein ◽  
Active Ovary ◽  
The Mean ◽  
Significant Change

SUMMARY The levels of free oestrogen (oestrone and oestradiol-17β) in plasma in the ovarian vein were determined in three groups, each of 27 ewes, at nine intervals at about the time of oestrus. One group had a normal oestrus while the other two had been treated for 16 days with intravaginal sponges containing either 10 or 30 mg of a synthetic progestagen (Cronolone, Searle). In untreated ewes, the mean level (corrected) of oestradiol-17β in plasma from the active ovary rose from 25·3 ng/100 ml at −48 h to a peak of 91·6 ng/100 ml at 0 h (onset of oestrus) and then fell. There was evidence of biphasic production. The mean level of oestrone was relatively high (13·0 ng/100 ml) at −48 h; it fell to 2·0 ng/100 ml between −36 and −24 h and then rose again to 9·4 ng/100 ml at + 12 h. There was no significant change, with time, in the plasma levels of either oestrogen from the non-active ovary. The total amounts of oestradiol-17β and of oestrone produced from both ovaries at an oestrous period were estimated to average 9·7 and 2·4 μg. In treated ewes, a similar pattern of production of oestradiol-17β was shown by the ewes treated with 30 mg Cronolone. That of ewes treated with 10 mg differed (P < 0·01). Peak level was reached at an earlier stage, relative to the onset of oestrus, and it declined more rapidly, the total amount of oestrogen produced (oestrone + oestradiol-17β) was less (10 mg Cronolone, 8·6 μg; 30 mg Cronolone, 12·1 μg; normal oestrus, 12·1 μg), and there was no biphasic production.

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