J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J. Anim Sci. 1986. 62:191-198.
© 1986 American Society of Animal Science
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Procknor, M.
Right arrow Articles by Harms, P. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Procknor, M.
Right arrow Articles by Harms, P. G.

Temporal Relationship of the Pulsatile Fluctuation of Luteinizing Hormone and Progesterone in Cattle: A Time Series Cross-Correlation Analysis1

M. Procknor2, S. Dachir, R. E. Owens, D. E. Little and P. G. Harms

Texas A&M University3, College Station 77843

Abstract

The temporal relationship between the pulsatile patterns of plasma luteinizing hormone (LH) and progesterone (P4) was studied in mid-luteal (ML) and early-pregnant (EP) dairy cows. Blood samples were collected (via external jugular vein cannulae) at 10-min intervals for 16 h in 5 ML cows (d 10 to 12 of the cycle) and for 10 h in 5 EP cows (d 52 to 56 of gestation). Concentrations of LH and P4 were determined by radioimmunoassays and a time series cross-correlation analysis was utilized to evaluate the temporal relationship between them. A pulsatile pattern was found for both hormones in both groups, and in all animals LH peaks were uniformly followed by P4 peaks. In 80% of the cows in both groups the highest cross-correlation occurred between samples LH (n) and P4 (n+1) (n = sample number), suggesting that a lag time of about 10 min is necessary for luteal stimulation. Results from both groups demonstrate that P4 is released from the corpus luteum in a pulsatile manner and that its release is at least partially dependent upon the pulsatile pattern of plasma LH. Correlation coefficients between LH and P4 mean level, basal levels, peak frequencies and peak amplitudes obtained in both groups indicate that the conceptus alters the hypothalamic-pituitary-ovarian relationship found in the ML cows, suggesting the existence of another factor(s) acting along with LH to release P4 in EP cows.

Footnotes

1 Journal Paper TA-20180, Texas A&M Univ. Agr. Exp. Sta.

2 Present address: Estacão Experimental de Zootecnia de Sertãozinho, Instituto de Zootecnia, São Paulo, Brazil. Sponsored by CNPq, Brazil.

3 Dept. of Anim. Sci., Texas Agr. Exp. Sta.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1986 by the American Society of Animal Science.