DIETARY RESTRICTION AND THE ENDOCRINE TESTIS; SIMULATION OF THE SYSTEMIC EFFECTS OF SEVERE COLD(−5 °C)

1965 ◽  
Vol 43 (5) ◽  
pp. 809-817 ◽  
Author(s):  
M. J. Perrault ◽  
L. P. Dugal

Previous work has suggested that the degeneration of the male reproductive system caused by severe cold (−5 °C; 18–32 days) represents the sum of the following factors: (a) systemic, or metabolic alterations in various structures of the entire organism; (b) endocrine, or neurohumoral events, especially androgenic.Observation of changes in weight of the accessory sex organs, prostate and seminal vesicles, as indicators of androgenic function, permits a demonstration of the two separate effects of cold. A restricted diet given to animals at room temperature results in a loss of body weight (percentage of control) almost identical in rate and in level with the loss caused by cold, and simulates the systemic component of the action of cold; the observed loss of weight of the accessories follows the proportionality (nonlinear) between body weight and organ weight. The further loss observed in the accessories of the cold-exposed rat may then be taken to represent the endocrine component, that is, the true androgenic depression; testosterone treatment in the "starved" castrate at room temperature shows the dissociation between the two components.

1954 ◽  
Vol 32 (1) ◽  
pp. 41-49 ◽  
Author(s):  
D. W. Snair ◽  
Sybil E. Jaffray ◽  
H. C. Grice ◽  
L. I. Pugsley

The temporary effects of the administration of stilbestrol upon body weight, weight of the accessory sex organs, and the reproductive capacity of the male white rat have been studied. A linear relationship was obtained when the logarithm of the dose of stilbestrol administered (0.0125 to 5.0 mgm.) was plotted against the percentage decrease in testes weight. This same relationship was also found when the log of the dose was plotted against the percentage decrease in body weight although this line had a much more gradual slope.When the administration of stilbestrol was discontinued, the seminal vesicles coagulating glands, and ventral prostrates regained their weight by the third to fourth week but the weights of the testes remained below the control values until the sixth to ninth week. In a breeding experiment it was shown that a daily dose of 7.5 μgm. of stilbestrol causes sterility in the male. This does also slightly affected the weight of the accessory sex organs and their cellular structure.


1954 ◽  
Vol 32 (1) ◽  
pp. 41-49 ◽  
Author(s):  
D. W. Snair ◽  
Sybil E. Jaffray ◽  
H. C. Grice ◽  
L. I. Pugsley

The temporary effects of the administration of stilbestrol upon body weight, weight of the accessory sex organs, and the reproductive capacity of the male white rat have been studied. A linear relationship was obtained when the logarithm of the dose of stilbestrol administered (0.0125 to 5.0 mgm.) was plotted against the percentage decrease in testes weight. This same relationship was also found when the log of the dose was plotted against the percentage decrease in body weight although this line had a much more gradual slope.When the administration of stilbestrol was discontinued, the seminal vesicles coagulating glands, and ventral prostrates regained their weight by the third to fourth week but the weights of the testes remained below the control values until the sixth to ninth week. In a breeding experiment it was shown that a daily dose of 7.5 μgm. of stilbestrol causes sterility in the male. This does also slightly affected the weight of the accessory sex organs and their cellular structure.


1972 ◽  
Vol 126 (2) ◽  
pp. 291-294 ◽  
Author(s):  
C. Rovinetti ◽  
C. Bovina ◽  
B. Tolomelli ◽  
M. Marchetti

1. The effects of castration and testosterone treatment on enzymic activities involved in folate coenzyme metabolism in the liver and in accessory sex organs of male adult rats were studied. 2. In the liver of castrated rats the concentration of 10-formyltetrahydrofolate (10-HCO-H4folate) synthetase and tetrahydrofolate (H4folate) dehydrogenase were significantly decreased whereas that of 5,10-methylenetetrahydrofolate dehydrogenase increased; the treatment with five doses of testosterone caused a return to normal values of these activities. 3. In the prostate of castrated rats a pronounced decrease in H4folate dehydrogenase, serine hydroxymethyltransferase and 10-HCO-H4folate synthetase activities was observed. The administration of testosterone restored the enzymic activities to normal values. 4. In the seminal vesicles of castrated rats only 10-HCO-H4folate synthetase was markedly depressed; testosterone treatment not only restored activity to normal values but raised it to higher than normal values. The slight changes observed in other enzymic activities also returned to normal values with the hormone treatment. 5. These results are discussed in relation to a possible control mechanism of folate metabolism by testosterone.


1974 ◽  
Vol 77 (2) ◽  
pp. 287-297 ◽  
Author(s):  
Rüdiger Ghraf ◽  
Edmund Rodney Lax ◽  
Hanns-Georg Hoff ◽  
Herbert Schriefers

ABSTRACT The androgens testosterone and 5α-dihydrotestosterone, the anabolic drug 19-nortestosterone and the anti-androgen cyproterone acetate were investigated with regard to their modifying action on the sexual differentiation of the activities of rat liver enzymes involved in steroid hormone metabolism. The activities of the enzymes (Δ4-5α-hydrogenase, 20-ketoreductase, 3α-and 3β-hydroxysteroid dehydrogenase, NAD- and NADP-dependent Δ4-3β-hydroxysteroid dehydrogenase, total steroid hydroxylases, 7α- and 16α-hydroxylase) were determined in cell-free liver fractions of male animals castrated on day 25 of life and killed on day 90; and of castrated animals which, from day 75 to 89 received daily sc injections (0.3 mg/100 g body weight) of the anabolic drug or the androgen only or in combination with cyproterone acetate (3 mg/100 g body weight). With the exception of 7α-hydroxylase castration leads to a feminization of the enzyme activity pattern. However, the degree of feminization varies from enzyme to enzyme. The administration of testosterone or of 5α-dihydrotestosterone reverses the effect of castration. With 5α-dihydrotestosterone activity values were reached which in some cases were significantly higher than those obtained with testosterone. Although both androgens restored the enzyme activities to the normal male values, neither androgen was able to compensate for the weight loss of the seminal vesicles in the dose administered. The administration of 19-nortestosterone in the same dose as testosterone is only 30 % as effective in restoring the weight loss of the seminal vesicles, but leads to identical activities of Δ4-5α-hydrogenase and of hydroxysteroid dehydrogenases as are found for testosterone. 19-Nortestosterone is without influence on the activities of total steroid hydroxylases and of 16α-hydroxylase. 16α-Hydroxylase is the only enzyme in which the activity enhancing effects of testosterone or of 5α-dihydrotestosterone can be completely blocked by the simultaneous administration of the anti-androgen cyproterone acetate. In all other enzyme activities the anti-androgen does not interfere with the effect of the androgens although it blocks their action on the weight restitution of the seminal vesicles by 60–70 %. 7α-Hydroxylase does not exhibit any androgen dependency. Neither castration nor the subsequent administration of the two androgens, or of the anabolic drug leads to any alterations in activity. However, it is interesting to note that the administration of cyproterone acetate does cause an increase in activity.


2021 ◽  
pp. 089719002110215
Author(s):  
Sara A. Atyia ◽  
Keaton S. Smetana ◽  
Minh C. Tong ◽  
Molly J. Thompson ◽  
Kari M. Cape ◽  
...  

Background: Dexmedetomidine is a highly selective α2-adrenoreceptor agonist that produces dose-dependent sedation, anxiolysis, and analgesia without respiratory depression. Due to these ideal sedative properties, there has been increased interest in utilizing dexmedetomidine as a first-line sedative for critically ill patients requiring light sedation. Objective: To evaluate the ability to achieve goal intensive care unit (ICU) sedation before and after an institutional change of dosing from actual (ABW) to adjusted (AdjBW) body weight in obese patients on dexmedetomidine. Methods: This study included patients ≥ 18 years old, admitted to a surgical or medical ICU, required dexmedetomidine for at least 8 hours as a single continuous infusion sedative, and weighed ≥ 120% of ideal body weight. Percentage of RASS measurements within goal range (−1 to +1) during the first 48 hours after initiation of dexmedetomidine as the sole sedative agent or until discontinuation dosed on ABW compared to AdjBW was evaluated. Results: 100 patients were included in the ABW cohort and 100 in the AdjBW cohort. The median dosing weight was significantly higher in the ABW group (95.9 [78.9-119.5] vs 82.2 [72.1-89.8] kg; p = 0.001). There was no statistical difference in percent of RASS measurements in goal range (61.5% vs 69.6%, p = 0.267) in patients that received dexmedetomidine dosed based on ABW versus AdjBW. Conclusion: Dosing dexmedetomidine using AdjBW in obese critically ill patients for ongoing ICU sedation resulted in no statistical difference in the percent of RASS measurements within goal when compared to ABW dosing. Further studies are warranted.


Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 781 ◽  
Author(s):  
Katherine F. Wallis ◽  
Stepan B. Melnyk ◽  
Isabelle R. Miousse

Dietary methionine restriction is associated with improved health outcomes and an increase in lifespan in animal models. We have previously shown that an increase in dietary methionine induces alteration in the intestinal microbiome. The composition of the intestinal microbiota is a determinant of health and we, therefore, hypothesized that dietary methionine restriction would also induce changes in the murine microbiome. After one month on a methionine-restricted diet, five-month-old male and female C57BL/6 mice had decreased levels of serum methionine, without changes in body weight. We identified a decrease in the hepatic methylation status of animals fed a methionine-restricted diet compared to controls. This decrease was not associated with changes in DNA or protein methylation in the liver. In males, we saw an increase in families Bacteroidaceae and Verrucoccaceae (mostly A. mucinophila) and a decrease in Rumminococcaceae in animals fed a methionine-restricted diet compared to controls. In females, Bacteroidales family S24-7 was increased two-fold, while families Bacteroidaceae, Verrucoccaceae, Rumminococcaceae, and Rikenellaceae were decreased compared to controls. In summary, feeding a methionine-restricted diet for one month was associated with significant and sex-specific changes in the intestinal microbiome.


1989 ◽  
Vol 123 (1) ◽  
pp. 83-91 ◽  
Author(s):  
K.-L. Kolho ◽  
I. Huhtaniemi

ABSTRACT The acute and long-term effects of pituitary-testis suppression with a gonadotrophin-releasing hormone (GnRH) agonist, d-Ser(But)6des-Gly10-GnRH N-ethylamide (buserelin; 0·02, 0·1, 1·0 or 10 mg/kg body weight per day s.c.) or antagonist, N-Ac-d-Nal(2)1,d-p-Cl-Phe2,d-Trp3,d-hArg(Et2)6,d-Ala10-GnRH (RS 68439; 2 mg/kg body weight per day s.c.) were studied in male rats treated on days 1–15 of life. The animals were killed on day 16 (acute effects) or as adults (130–160 days; long-term effects). Acutely, the lowest dose of the agonist decreased pituitary FSH content and testicular LH receptors, but with increasing doses pituitary and serum LH concentrations, intratesticular testosterone content and weights of testes were also suppressed (P< 0·05–0·01). No decrease was found in serum FSH or in weights of accessory sex organs even with the highest dose of the agonist, the latter finding indicating continuing secretion of androgens. The GnRH antagonist treatment suppressed pituitary LH and FSH contents and serum LH (P< 0·05–0·01) but, as with the agonist, serum FSH remained unaltered. Testicular testosterone and testis weights were decreased (P <0·01) but testicular LH receptors remained unchanged. Moreover, the seminal vesicle and ventral prostate weights were reduced, in contrast to the effects of the agonists. Pituitary LH and FSH contents had recovered in all adult rats treated neonatally with agonist and there was no effect on serum LH and testosterone concentrations or on fertility. In contrast, in adult rats treated neonatally with antagonist, weights of testis and accessory sex organs remained decreased (P <0·01–0·05) but hormone secretion from the pituitary and testis had returned to normal except that serum FSH was increased by 80% (P <0·01). Interestingly, 90% of the antagonist-treated animals were infertile. It is concluded that treatment with a GnRH agonist during the neonatal period does not have a chronic effect on pituitary-gonadal function. In contrast, GnRH antagonist treatment neonatally permanently inhibits the development of the testis and accessory sex organs and results in infertility. Interestingly, despite the decline of pituitary FSH neonatally, neither of the GnRH analogues was able to suppress serum FSH values and this differs from the concomitant changes in LH and from the effects of similar treatments in adult rats. Journal of Endocrinology (1989) 123, 83–91


Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 530-562
Author(s):  
M. Enesco ◽  
C. P. Leblond

While the organs and tissues of the young rat are known to increase in size with age (Donaldson, 1924), little is known of the role played by the component cells in this increase. There is evidence that cells enlarge (Levi, 1906; Plenk, 1911) and new cells are added (Strasburger, 1893), but we do not know to what extent the enlargement and proliferation of the cells cause the growth of organs and tissues. The present work is an attempt to clarify this problem. In the past, the growth of organs and tissues has often been measured by weight gain (Donaldson, 1924). However, this approach might be misleading, since the body-weight may increase in the absence of growth, for instance as a result of fat-storage in old rats, of pregnancy in females, and even of changes in room temperature.


1977 ◽  
Vol 23 (3) ◽  
pp. 331-336 ◽  
Author(s):  
S. Stavric ◽  
D. Jeffrey

Infant mice were injected orally with preparations containing Escherichia coli heat-stable enterotoxin (ST) and Evans blue dye, and incubated at 22 °C. With enterotoxin-positive samples, the stomach was distended and contained essentially all of the dye. With enterotoxin-negative samples, the stomach remained normal in size and the dye passed freely into the intestines. The time required to obtain the maximum ratio of gut weight to body weight varied from 30 to 90 min and was dependent upon the concentration of enterotoxin. Heat-labile enterotoxin (LT) had no effect during this period.Based on these findings, the mouse incubation time was reduced from 4 h to 90 min, and the heating of test samples was retained only for confirmation of ST. The location of the dye and stomach distention served as an indicator of positive responses to ST. Incubation of the mice at room temperature (22 °C) was found satisfactory.


2018 ◽  
Vol 9 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Sharifah Nurul Ain Syed Hashim ◽  
Sarani Zakaria ◽  
Chin Hua Chia ◽  
Sharifah Nabihah Syed Jaafar

In this study, soda alkali lignin from oil palm empty fruit bunch (EFB-AL) and kenaf core (KC-AL) are esterified with maleic anhydride under two different conditions, namely i) pyridine at temperature of 120°C for 3h and ii) aqueous alkaline solution at room temperature for 4h. As a result, the weight percentage gain (WPG) of the esterified EFB-AL (EFB-EL) and esterified KC-AL (KC-EL) in pyridine demonstrated a higher compared to aqueous alkaline solution. The FT-IR results of EFB-EL and KC-EL in both solvents exhibited some changes at the carbonyl and hydroxyl groups. Furthermore, the esterification process induced the carboxylic peak to appear in both alkali lignin samples. The outcome is confirmed by conducting H-NMR analysis, which demonstrated ester and carboxylic acid peaks within the spectral analysis. Finally, the TGA results showed both EFB-EL and KC-EL that are exposed to aqueous alkaline actually possessed better thermal stability and higher activation energy (Ea) compared to the esterified samples in pyridine.


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