Diurnal Variations of Plasma Testosterone in Stallions
Open Access
- 1 September 1976
- journal article
- research article
- Published by Oxford University Press (OUP) in Biology of Reproduction
- Vol. 15 (2) , 158-162
- https://doi.org/10.1095/biolreprod15.2.158
Abstract
Plasma testosterone was measured in the peripheral blood of normal stallions by radioimmunoassay. In 24 stallions a single blood sample was taken between 9:30 and 10:30 a.m. and the mean testosterone concentration was 3.06 ± 1.27 ng/ml. In the other 8 stallions, blood was withdrawn every 4 h. In all 8 stallions there was evidence of a diurnal rhythm. The maximum mean blood plasma concentration of testosterone was observed in the sample collected at 8:00 a.m. and the minimum at 8:00 p.m. These differences in the blood plasma testosterone level are significant (P<0.10).This publication has 6 references indexed in Scilit:
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