The effect of a single injection of estradiol benzoate on thyroid function in intact male rats

1968 ◽  
Vol 46 (4) ◽  
pp. 697-700 ◽  
Author(s):  
K. Brown-Grant
Keyword(s):  
Body Weight ◽  
Thyroid Gland ◽  
Thyroid Function ◽  
Dose Level ◽  
Adult Male ◽  
Single Injection ◽  
Estradiol Benzoate ◽  
Male Rats ◽  
Intact Male ◽  
Federation Proc

The changes observed in the metabolism of radioiodide and radiophosphorus by the thyroid gland of intact adult male rats following a single injection of estradiol benzoate (4 μg/100 g body weight) are consistent with the suggestion (F. Labrie, G. Pelletier, and C. Fortier. Federation Proc. 26, 484 (1967). Abstr.) that at this dose level estrogen causes a hypersecretion of TSH in such animals.

Dietary fat and adiposity: a dose-response relationship in adult male rats fed isocalorically

1995 ◽  
Vol 268 (4) ◽  
pp. E546-E550 ◽  
Author(s):  
C. N. Boozer ◽  
G. Schoenbach ◽  
R. L. Atkinson
Keyword(s):  
Body Weight ◽  
Body Fat ◽  
Adult Male ◽  
Dietary Fat ◽  
Male Rats ◽  
Control Group ◽  
Low Fat Diet ◽  
Mesenteric Fat ◽  
Total Body Fat ◽  
Total Body

This study examined the effects of increasing levels of dietary fat fed isocalorically on body weight, body composition, and adipose distribution. Adult male rats were weight matched into four groups. One group that was fed a low-fat diet (12%) served as reference controls. The other three groups were fed diets of 24, 36, or 48% fat in amounts to equal the energy intake of the control group. After 6 wk, body weights of the four groups were not significantly different. Intrascapular brown fat did not differ between groups. Total body fat and adipose depot weights, however, increased in proportion to the level of fat in the diet. Total body fat and retroperitoneal and mesenteric depot weights of the 48% fat group were greater than controls (P < 0.05). Mesenteric fat in this group was also significantly increased over all other groups (P < 0.05). These results show that high-fat diets fed to adult animals cause increased body fat in the absence of significant changes in body weight and that mesenteric fat is increased disproportionately.

THE EFFECT OF CERTAIN METALLIC CATIONS ON THE IODIDE UPTAKE IN THE THYROID GLAND OF MICE

1964 ◽  
Vol 46 (4) ◽  
pp. 643-652 ◽  
Author(s):  
M. Anbar ◽  
M. Inbar
Keyword(s):  
Body Weight ◽  
Thyroid Gland ◽  
Dose Level ◽  
Iodine Uptake ◽  
Iodide Uptake ◽  
Nickel Ions ◽  
Zinc Cadmium ◽  
Metallic Cations

ABSTRACT Ferric, cupric, mercuric, zinc, cadmium and nickel ions at the dose level of 0.1 millimole per kg body weight were found to decrease the uptake of iodine in the thyroid gland. Manganous ions exhibited a similar effect when the dose was doubled. A parallel decrease in the BF4− uptake could be demonstrated; this suggests an interference at the stage of iodide accumulation. Cobaltous, cobaltic, magnesium, beryllium and zirconium ions were shown to have no effect on iodine uptake at the same dose level. The mechanism of the effect is discussed.

scholarly journals In vitro pituitary and testicular effects of the leptin-related synthetic peptide leptin(116-130) amide involve actions both similar to and distinct from those of the native leptin molecule in the adult rat

2000 ◽  
pp. 406-410 ◽  
Author(s):  
M Tena-Sempere ◽  
L Pinilla ◽  
LC Gonzalez ◽  
J Navarro ◽  
C Dieguez ◽  
...  
Keyword(s):  
Body Weight ◽  
Adult Male ◽  
Body Weight Gain ◽  
Biologically Active ◽  
Male Rats ◽  
Male Rat ◽  
Gh Secretion ◽  
Adult Rat ◽  
Testosterone Secretion

The obese gene (ob) product, leptin, has recently emerged as a key element in body weight homeostasis, neuroendocrine function and fertility. Identification of biologically active, readily synthesized fragments of the leptin molecule has drawn considerable attention, as they may provide a powerful tool for detailed characterization of the biological actions of leptin in different experimental settings. Recently, a fragment of mouse leptin protein comprising amino acids 116-130, termed leptin(116-130) amide, was shown to mimic the effects of the native molecule in terms of body weight gain and food intake, and to elicit LH and prolactin (PRL) secretion in vivo. As a continuation of our previous experimental work, the present study reports on the effects of leptin(116-130) amide on basal and stimulated testosterone secretion by adult rat testis in vitro. In addition, a comparison of the effects of human recombinant leptin and leptin(116-130) amide at the pituitary level on the patterns of LH, FSH, PRL and GH secretion is presented. As reported previously by our group, human recombinant leptin(10(-9)-10(-7)M) significantly inhibited both basal and human chorionic gonadotrophin (hCG)-stimulated testosterone secretion in vitro. Similarly, incubation of testicular tissue in the presence of increasing concentrations of leptin(116-130) amide (10(-9)-10(-5)M) resulted in a dose-dependent inhibition of basal and hCG-stimulated testosterone secretion; a reduction that was significant from a dose of 10(-7)M upwards. In addition, leptin(116-130) amide, at all doses tested (10(-9)-10(-5)M), significantly decreased LH and FSH secretion by incubated hemi-pituitaries from adult male rats. In contrast, in the same experimental protocol, recombinant leptin(10(-9)-10(-7)M) was ineffective in modulating LH and FSH release. Finally, neither recombinant leptin nor leptin(116-130) amide were able to change basal PRL and GH secretion in vitro. Our results confirm the ability of leptin, acting at the testicular level, to inhibit testosterone secretion, and map the effect to a domain of the leptin molecule that lies between amino acid residues 116 and 130. In addition, we provide evidence for a direct inhibitory action of leptin(116-130) amide on pituitary LH and FSH secretion, a phenomenon not observed for the native leptin molecule, in the adult male rat.

Effects of Insulin, Metrazol, and Electroconvulsive Shocks upon Learning to Learn 30 Successive Reversal Problems by Rats

1970 ◽  
Vol 26 (2) ◽  
pp. 551-558 ◽  
Author(s):  
Loh Seng Tsai ◽  
Vernon J. Perez ◽  
Jefferson M. Koonce
Keyword(s):  
Body Weight ◽  
Potassium Chloride ◽  
Electric Current ◽  
Adult Male ◽  
Male Rats ◽  
Learning To Learn ◽  
Successive Reversal ◽  
Insulin Group ◽  
Weight One ◽  
Better Than

To determine the relative effects of insulin, metrazol and electroconvulsive shocks upon learning to learn 30 successive reversal problems by rats, an enclosed square T-maze was used, with water as incentive after 23 hr. of deprivation. S had to achieve 9 correct out of 10 daily trials before a problem was reversed. 40 adult male rats were equally divided into a control and 3 differently shocked groups. Shocks were administered on 3 alternate days followed by 2 days of rest. Each time, Ss of the 4 groups received respectively 0.5 cc. of saline, 55 mg. of metrazol per kg. of body-weight, one unit of insulin per 20 gm. of body-weight, and an electric current of 50 ma. at 25 v for 150 msec. Convulsion in the insulin group was prevented by an injection of dextrose and potassium chloride. The control was significantly superior to the 3 shocked groups which were remarkably similar or practically identical in their performance during the initial 6 problems. Thereafter, both the non-convulsive (saline and insulin) groups did better than the 2 convulsive groups either in terms of error, day, or one-trial reversal score.

EFFECTS OF TESTOSTERONE MEDIATED OR MODULATED BY PITUITARY FACTORS

1975 ◽  
Vol 67 (1) ◽  
pp. 71-79 ◽  
Author(s):  
P. DE MOOR ◽  
M. ADAM-HEYLEN ◽  
H. VAN BAELEN ◽  
G. VERHOEVEN
Keyword(s):  
Body Weight ◽  
Testosterone Propionate ◽  
Total Body Weight ◽  
Seminal Vesicles ◽  
Female Rats ◽  
Male Rats ◽  
Intact Male ◽  
Adult Rats ◽  
Organ Weights ◽  
Total Body

SUMMARY Adult rats of both sexes were either gonadectomized or hypophysectomized and gonadectomized. Three to eight weeks later they were treated for 14 consecutive days with oil or with 75 or 200 μg testosterone propionate (TP) per 100 g body weight. The animals were killed and for each sex the gonadectomized animals were compared with the hypophysectomized-gonadectomized animals as far as their NADPH- and NADH-dependent 3α-hydroxysteroid dehydrogenases (3α-HSD) in renal microsomes, transcortin levels in serum and five organ weights relative to total body weight were concerned. For two of the latter, i.e. the relative kidney and prostatic weights, no significant differences were found. Transcortin levels, relative adrenal weights and renal NADPH-dependent 3α-HSD activities were higher in oil-treated gonadectomized animals than in oil-treated hypophysectomized-gonadectomized animals. The opposite was found for the relative weights of uterus and seminal vesicles and renal NADH-dependent 3α-HSD activities. These differences between gonadectomized and hypophysectomized-gonadectomized animals disappeared after TP treatment as far as transcortin levels were concerned but remained for the five other parameters. After gonadectomy sexual differences subsisted for all parameters studied. But whereas intact male rats had higher NADH-dependent 3α-HSD activities than female rats the opposite was found after gonadectomy. After gonadectomy plus hypophysectomy the between sex differences disappeared as far as transcortin levels were concerned but remained in the other parameters studied.

Sensitizing effect of treatment with estrogens on TSH response to TRH in male rats.

1977 ◽  
Vol 233 (3) ◽  
pp. E235 ◽  
Author(s):  
A De Lean ◽  
F Labrie
Keyword(s):  
Estradiol Benzoate ◽  
Thyroid Stimulating Hormone ◽  
Prolactin Secretion ◽  
Male Rats ◽  
Intact Male ◽  
Basal Plasma ◽  
Prolactin Content ◽  
High Doses ◽  
Sensitizing Effect ◽  
Plasma Prl

Daily administration of estradiol benzoate (10 microgram/100 g body wt) to intact male rats led to a twofold increase of the plasma TSH (thyroid-stimulating hormone) response to thyrotropin-releasing hormone (TRH) after 4 and 7 days of treatment whereas the basal plasma TSH level was not affected. The basal plasma PRL concentration and the PRL response to TRH were both markedly increased by estrogen treatment. The TSH pituitary content remained unchanged, whereas the PRL pituitary content increased in parallel with the effect on PRL secretion. Treatment with estrogens for 1 wk sensitized the TSH secretory response to low doses of TRH (10 ng), whereas no significant effect on the response was found at high doses of the neurohormone. The present data show that the stimulatory effect of estrogens on the TSH response to TRH is due to true sensitization of the thyrotrophs to the action of the neurohormone, whereas that on prolactin secretion can result partly from increased pituitary prolactin content.

scholarly journals Different types of soluble fermentable dietary fibre decrease food intake, body weight gain and adiposity in young adult male rats

2014 ◽  
Vol 11 (1) ◽  
pp. 36 ◽  
Author(s):  
Clare L Adam ◽  
Patricia A Williams ◽  
Matthew J Dalby ◽  
Karen Garden ◽  
Lynn M Thomson ◽  
...  
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Young Adult ◽  
Food Intake ◽  
Adult Male ◽  
Dietary Fibre ◽  
Body Weight Gain ◽  
Male Rats ◽  
Decrease Food Intake ◽  
Different Types

Perinatal estradiol benzoate administration affects control of ventilation in adult male rats

1992 ◽  
Vol 52 (6) ◽  
pp. 1113-1116 ◽  
Author(s):  
Evelyn H. Schlenker ◽  
Max Goldman ◽  
Susan Walsh
Keyword(s):  
Adult Male ◽  
Estradiol Benzoate ◽  
Male Rats ◽  
Control Of Ventilation
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