Plasma concentrations of luteinizing hormone and adrenocorticotropic hormone in blood collected during the luteal and follicular phases of the estrous cycle in cows.

Rebecca L Davies, S. D. Johnston, D. M. Pasternak, B. E. Seguin, J. E. Wheaton

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Luteinizing hormone (LH) and ACTH concentrations were measured in plasma from 7 cows to determine whether ACTH secretion changes with the phase of the estrous cycle, and to determine whether any ACTH peaks are associated with LH peaks. Blood was collected every 5 minutes for 190 minutes during the luteal and follicular phases of the estrous cycle. Radioimmunoassays were used to measure ACTH and LH in plasma. Mean concentration of ACTH in all cows did not differ significantly between luteal (35.1 +/- 8.0 pg/ml) and follicular (37.5 +/- 9.4 pg/ml) phases of the estrous cycle. Mean concentration of luteal-phase LH of all cows (2.0 +/- 1.1 ng/ml) was significantly (P less than 0.01) lower than mean concentration of follicular-phase LH (5.4 +/- 1.6 ng/ml). Frequency of peaks in ACTH concentration was low during the sampling period. Mean number of luteal-phase ACTH peaks (0.29 +/- 0.49) was not significantly different from that of follicular-phase samples (0.43 +/- 0.530). Unlike ACTH, mean frequency of LH peaks was significantly (P less than 0.05) higher in plasma from cows in the follicular phase of the estrous cycle (2.9 +/- 0.7), compared with that from cows in the luteal phase (0.29 +/- 0.49).

Original languageEnglish (US)
Pages (from-to)909-915
Number of pages7
JournalAmerican journal of veterinary research
Volume53
Issue number6
StatePublished - Jun 1992

Fingerprint Dive into the research topics of 'Plasma concentrations of luteinizing hormone and adrenocorticotropic hormone in blood collected during the luteal and follicular phases of the estrous cycle in cows.'. Together they form a unique fingerprint.

Cite this