|
|
||||||||
Biology of Reproduction, Vol 21, 755-763, Copyright © 1979 by Society for the Study of Reproduction
1 Reproductive Physiology Research Laboratory,
Department of Animal Science,
North Carolina State University,
Raleigh, North Carolina 27650 Relationships of characteristics of 24 h profiles for concentrations of corticosteroids (CS),
luteinizing hormone (LH) and testosterone (T) in peripheral blood with episodic and exogenously
induced elevations of T were studied in bulls. Hourly blood samples were collected via jugular vein
cannula for 24 consecutive h from 11 puberal Angus bulls. Exogenous bovine LH (1 mg) was
injected at the end of the 24 h period. The overall lag correlation between concentrations of LH
at one hour and concentrations of T at the subsequent hour (LAG-LHTCORR) was significant
(r = 0.34). Prolonged maintenance of elevated concentrations of CS were coincident with baseline
concentrations of LH (BASAL-LH) and T (BASAL-T). Episodic LH and T peaks occurred at the
time of baseline concentrations of CS (BASAL-CS) or were preceded by the decline of elevated
concentrations of CS. A significant negative correlation (r = -0.14) was obtained for the overall lag
correlation between concentrations of CS at one hour and concentrations of T at the subsequent
hour (LAG-CSTCORR). A negative relationship was observed between total area under 24 h profile
of CS (CS-AREA) and total area under 24 h profile of LH (LH-AREA) and between CS-AREA and
total area under 24 h profile of T (T-AREA). Peak concentration of T following LH injection varied
among bulls; bulls were ranked according to T response to exogenous LH and particular characteristics of 24 h profiles of concentrations of T and CS. Profile characteristics associated with T
response after exogenous LH was given were T-AREA, BASAL-T, CS-AREA and BASAL-CS. The
results of this study provide evidence that adrenal corticosteroids may exert a regulatory influence
upon both episodic and induced synthesis and secretion of T by the bovine testis.
Note:
ACKNOWLEDGMENTS
We are indepted to Dr. Harold Hafs for testosterone antiserum, to Dr. Leo Reichert, Jr. for purified
bovine LH (LER-1716-2), to Dr. Gordon Niswender
for antiserum to bovine LH (B-225) and to the NIAMD
for the bovine LH (NIH-LH-B9). The technical assistance of Ms. Z. Turner, Mr. B. Severt and Mr. J. Bragg
is gratefully acknowledged.
This article has been cited by other articles:
![]() |
K. R. Buckham Sporer, P. S. D. Weber, J. L. Burton, B. Earley, and M. A. Crowe Transportation of young beef bulls alters circulating physiological parameters that may be effective biomarkers of stress J Anim Sci, June 1, 2008; 86(6): 1325 - 1334. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |