Age-related changes in body weight, scrotal size and plasma testosterone levels in buffalo bulls ()

1984 ◽  
Vol 22 (6) ◽  
pp. 651-656 ◽  
Author(s):  
Manzoor Ahmad ◽  
M. Latif ◽  
Masood Ahmad ◽  
M.H. Qazi ◽  
N. Sahir ◽  
...  
Keyword(s):  
Body Weight ◽  
Plasma Testosterone ◽  
Testosterone Levels ◽  
Age Related ◽  
Age Related Changes

Seasonal and Age-Related Changes in Plasma Testosterone Levels in Mountain White-Crowned Sparrows

The Condor ◽  
1990 ◽  
Vol 92 (1) ◽  
pp. 166-173 ◽  
Author(s):  
Martin L. Morton ◽  
Linda E. Peterson ◽  
Douglas M. Burns ◽  
Noella Allan
Keyword(s):  
Plasma Testosterone ◽  
Testosterone Levels ◽  
Age Related ◽  
Age Related Changes

INFLUENCE OF METYRAPONE ON PLASMA CONCENTRATIONS OF TESTOSTERONE AND ANDROSTENEDIONE IN MAN

1971 ◽  
Vol 68 (3) ◽  
pp. 576-584 ◽  
Author(s):  
K. O. Nilsson ◽  
B. Hökfelt
Keyword(s):  
Body Weight ◽  
Male Patient ◽  
Gradual Increase ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Testosterone Levels ◽  
Basal Plasma ◽  
Normal Males ◽  
A Minor ◽  
Secondary Hypogonadism

ABSTRACT Metyrapone was administered either orally, 750 mg every four h, in a total of six doses, or intravenously 30 mg per kg body weight as a four h infusion. In three males with normal endocrine functions, metyrapone given orally or intravenously induced a fall in plasma testosterone and an elevation of androstenedione within 2–8 h. When metyrapone was administered to a patient given dexamethasone to suppress endogenous ACTH production, the androstenedione levels did not alter whereas the testosterone levels showed a slight, transient decrease. In two normal females metyrapone administration was followed by a marked increase in plasma androstenedione whereas testosterone showed only a minor, gradual increase. In one male patient with Addison's disease the basal plasma testosterone was normal whereas the level of androstenedione was low. Following metyrapone intravenously, there was a slight suppression of plasma testosterone but no change in the androstenedione concentration. In one patient with primary hypogonadism, two with secondary hypogonadism and two with Klinefelter's syndrome the plasma testosterone was low under basal conditions and did not change following metyrapone. Basal plasma androstenedione was within the range for normal males and increased markedly following metyrapone in all the cases.

scholarly journals Age-Related Alterations in Pituitary and Testicular Functions in Long-Lived Growth Hormone Receptor Gene-Disrupted Mice

Endocrinology ◽  
2007 ◽  
Vol 148 (12) ◽  
pp. 6019-6025 ◽  
Author(s):  
Varadaraj Chandrashekar ◽  
Christina R. Dawson ◽  
Eric R. Martin ◽  
Juliana S. Rocha ◽  
Andrzej Bartke ◽  
...  
Keyword(s):  
Growth Hormone Receptor ◽  
Receptor Gene ◽  
Delayed Puberty ◽  
Plasma Testosterone ◽  
Mrna Levels ◽  
Testosterone Levels ◽  
Gh Receptor ◽  
Age Related ◽  
Igf I ◽  
Plasma Prl

The somatotropic axis, GH, and IGF-I interact with the hypothalamic-pituitary-gonadal axis in health and disease. GH-resistant GH receptor-disrupted knockout (GHRKO) male mice are fertile but exhibit delayed puberty and decreases in plasma FSH levels, testicular content of LH, and prolactin (PRL) receptors, whereas PRL levels are elevated. Because the lifespan of GHRKO mice is much greater than the lifespan of their normal siblings, it was of interest to compare age-related changes in the hypothalamic-pituitary-gonadal axis in GHRKO and normal animals. Plasma IGF-I, insulin, PRL, LH, FSH, androstenedione and testosterone levels, and acute responses to GnRH and LH were measured in young (2–4 and 5–6 months of age) and old (18–19 and 23–26 months of age) male GHRKO mice and their normal siblings. Plasma IGF-I was not detectable in GHRKO mice. Plasma PRL levels increased with age in normal mice but declined in GHRKO males, and did not differ in old GHRKO and normal animals. Plasma LH responses to acute GnRH stimulation were attenuated in GHRKO mice but increased with age only in normal mice. Plasma FSH levels were decreased in GHRKO mice regardless of age. Plasma testosterone responses to LH stimulation were attenuated in old mice regardless of genotype, whereas plasma androstenedione responses were reduced with age only in GHRKO mice. Testicular IGF-I mRNA levels were normal in young and increased in old GHRKO mice, whereas testicular concentrations and total IGF-I levels were decreased in these animals. These findings indicate that GH resistance due to targeted disruption of the GH receptor gene in mice leads to suppression of testicular IGF-I levels, and modifies the effects of aging on plasma PRL levels and responses of the pituitary and testes to GnRH and LH stimulation. Plasma testosterone levels declined during aging in normal but not in GHRKO mice, and the age-related increase in the LH responses to exogenous GnRH was absent in GHRKO mice, perhaps reflecting a delay of aging in these remarkably long-lived animals.

Age-Related Changes in Distribution of Body Weight on Soles of Feet for Selected Actions and Postures

1997 ◽  
Vol 85 (3_suppl) ◽  
pp. 1263-1271 ◽  
Author(s):  
Toshiaki Yanagida ◽  
Takaaki Asami
Keyword(s):  
Body Weight ◽  
Weight Distribution ◽  
Healthy Subjects ◽  
Age Groups ◽  
The Body ◽  
The Other ◽  
Elderly Subjects ◽  
Age Related ◽  
Soles Of The Feet ◽  
Age Related Changes

We investigated age-related changes in the distribution of body weight on soles of feet in 878 healthy subjects ranging from 5 to 80 years of age. By modifying Morton's Staticometer, we constructed an instrument for measuring body-weight distribution over three areas of soles of the feet, the big toe (inner forefoot), the other four toes combined (outer forefoot) and the heels for both feet, thus a total of six areas. The weights in the six areas were recorded at the completion of nine selected actions and postures. We observed that for inhaling and exhaling standing postures, generally younger subjects had a ratio close to 1:2:3 for weights recorded for the inner toe:outer toes:heels as observed by Morton, but elderly subjects had a smaller value than 3 for the heel. The body-weight distribution tended to shift from heels to outer toes across age groups, which was more distinctly observed in women than in men.

Effects of Methanol Vapors on Testosterone Production and Testis Morphology in Rats

1991 ◽  
Vol 7 (4) ◽  
pp. 261-275 ◽  
Author(s):  
E. Lee ◽  
A.N. Brady ◽  
M.J. Brabec ◽  
T. Fabel
Keyword(s):  
Adverse Effect ◽  
Body Weight ◽  
Weight Ratio ◽  
Serum Testosterone ◽  
Exposure Period ◽  
Body Weight Ratio ◽  
Testosterone Levels ◽  
Age Related ◽  
Testosterone Synthesis ◽  
Testicular Degeneration

Potential toxic effects of methanol vapors on testicular produc tion of testosterone and the morphology of testes were investi gated using normal or methanol-sensitive folate-reduced rats. Methanol inhalation at the level of the current permissible expo sure limit, 200 ppm, for up to six weeks (8 hours/day, 5 days/ week), did not reduce serum testosterone levels in normal rats. Testes isolated from methanol-exposed (200 ppm) rats had the same capability as those from air-exposed rats in synthesizing testosterone whether testes were incubated in the absence or pres ence of hCG. The testes-to-body weight ratio of rats exposed up to 800 ppm methanol for up to 13 weeks (20 hours/day, 7 days/ week) were not different from those of the air-exposed rats. Fur thermore, methanol had no adverse effect on testicular morphol ogy at the end of the 13 week exposure period at 800 ppm in either normal rats or folate-reduced methanol-sensitive rats when they were 10 months old at the time of examination. Thus, these data indicate that low level methanol may not cause an inhibi tory effect on testosterone synthesis contrary to previous litera ture reports. However, a greater incidence of testicular degeneration was noticed in the 18 month old folate-reduced rats exposed to 800 ppm for 13 weeks (20 hours/day, 7 days/week), suggesting that methanol may have a potential to accelerate the age-related degeneration of the testes.

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