AGE-RELATED CHANGES IN FREE PLASMA TESTOSTERONE, DIHYDROTESTOSTERONE, AND OESTRADIOL

1975 ◽  
Vol 80 (1_Suppla) ◽  
pp. S57 ◽  
Author(s):  
K. M. Pirke ◽  
P. Doerr
Keyword(s):  
Plasma Testosterone ◽  
Age Related ◽  
Free Plasma ◽  
Age Related Changes

AGE RELATED CHANGES IN FREE PLASMA TESTOSTERONE, DIHYDROTESTOSTERONE AND OESTRADIOL

1975 ◽  
Vol 80 (1) ◽  
pp. 171-178 ◽  
Author(s):  
Karl M. Pirke ◽  
Peter Doerr
Keyword(s):  
Healthy Adult ◽  
Equilibrium Dialysis ◽  
Plasma Testosterone ◽  
Age Group ◽  
Adult Males ◽  
Age Related ◽  
Group I ◽  
Group Ii ◽  
Free Plasma ◽  
Age Related Changes

ABSTRACT The age related changes on free plasma testosterone (T), dihydrotestosterone (DHT) and oestradiol (Oe2) were determined in 82 healthy adult males. Forty-six subjects were between 22 and 61 years of age (group I), 36 between 67 and 93 years (group II). The percentage of free, non protein bound hormone was determined by equilibrium dialysis of undiluted plasma against isotonic phosphate buffer at 37°C. Total hormone concentrations were measured by radioimmunoassay. The percentage of free T was 2.24 % (median), 1.65–3.42 (95 percentiles) in group I and 1.65 % (1.24–2.26) in group II. The percentage of free DHT decreased from 1.17 % (0.80–2.03) in group I to 0.83% (0.52–1.55) in group II. The decrease in % free Oe2 was only very small: group I = 2.49% (2.13–2.96), ad group II = 2.31% (1.95–3.17). The fall in free T by 43.3% from 12.2 ng/100 ml (6.74–25.0) in group I to 6.90 ng/ml (3.57–10.6) in group II was twice as high as that of total T, which decreased on an average by 20.6%. Free DHT decreased by 25.8 %: group I = 578 pg/100 ml (266–987), group II = 429 pg/100 ml (168–723), while total DHT was not significantly different between the two groups (–1.9%). Free Oe2 was increased in old age: group I = 42.4 pg/100 ml (26.0–69.4), group II = 55.7 pg/100 ml (35.8–118.9). The increase in free Oe2 by 31.4% was almost as high as that of the total Oe2 (46.9%).

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

scholarly journals Age-related changes in testicular parameters and their relationship to thyroid hormones and testosterone in male Murrah buffaloes

2018 ◽  
Vol 61 (2) ◽  
pp. 191-195
Author(s):  
Vyankat Gangadhar Jadhav ◽  
Bagepalli Sathyanarayana Bharath Kumar ◽  
Sujata Pandita
Keyword(s):  
Correlation Coefficients ◽  
Plasma Testosterone ◽  
Blood Samples ◽  
Murrah Buffaloes ◽  
Scrotal Circumference ◽  
Age Related ◽  
Testicular Weight ◽  
Plasma Hormone ◽  
Age Related Changes ◽  
Plasma Triiodothyronine

Abstract. The present study aims to investigate the age-related changes in testicular parameters and their association with plasma triiodothyronine (T3), thyroxine (T4), and testosterone in male Murrah buffaloes. Testicular measurements and single blood samples were collected from male Murrah buffaloes (n= 103) aged between 6 months and 8 years. The correlation coefficients of average testicular length (ATL), paired testis width (PTW), and scrotal circumference (SC) in relation to age were 0.88, 0.91, and 0.90, respectively. The regression equation between testicular weight (TW) and age was Y=1.48×x0.005 (r= 0.90; R2= 0.79). Plasma T4 and testosterone increased significantly (p< 0.001) with age and their levels ranged between 12.9 and 41.8 and 0.05 and 1.48 ng mL−1, respectively. With respect to associations between testicular parameters and plasma hormone levels, we observed significant (p< 0.01) correlations between ATL, PTW, SC, TW, and plasma T4. A significant correlation (r= 0.31; p< 0.01) between plasma T4 and testosterone levels was also observed. However, the correlations between plasma T3 and testicular parameters and plasma T3 and testosterone were non-significant. From the present study, we conclude that plasma T4 is positively correlated with testicular parameters and plasma testosterone, indicating its role in testis development and steroidogenesis.

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

AGE RELATED CHANGES AND INTERRELATIONSHIPS BETWEEN PLASMA TESTOSTERONE, OESTRADIOL AND TESTOSTERONE-BINDING GLOBULIN IN NORMAL ADULT MALES

1973 ◽  
Vol 74 (4) ◽  
pp. 792-800 ◽  
Author(s):  
Karl M. Pirke ◽  
Peter Doerr
Keyword(s):  
Binding Capacity ◽  
Plasma Testosterone ◽  
Age Group ◽  
Adult Males ◽  
Total Plasma ◽  
Biological Meaning ◽  
Age Related ◽  
Group I ◽  
Peripheral Conversion ◽  
Age Related Changes

ABSTRACT Testosterone (T), oestradiol-17β (Oe2) and binding capacity of the testosterone-binding globulin (TeBG) were measured in plasma of 84 adult males (22–90 years). The medians for age group I (22– 61 years, n = 50) were: T 545 ng/100 ml, Oe2 1.66 ng/100 ml, TeBG capacity 1.44 μg T/100 ml; the medians for age group II (67–90 years, n = 34) were: T 459 ng/100 ml, Oe2 2.56 ng/100 ml, TeBG capacity 2.05 μg T/100 ml. The decrease of T and the increase of Oe2 and TeBG capacity with age were significant. The significant correlation (P < 0.01) for either age group between T and Oe2 may be ascribed to a simultaneous secretion and/or a peripheral conversion of T to Oe2. The significant correlation (P < 0.05) between T and TeBG for the old age group probably reflects the comparatively high percentage of total plasma T bound to TeBG. The biological meaning of the correlation between Oe2 and TeBG is discussed.

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