EurekaMag.com logo
+ Site Statistics
References:
52,654,530
Abstracts:
29,560,856
PMIDs:
28,072,755
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

Differences in immunological and biological activity of serum luteinizing hormone during the bovine estrous cycle



Differences in immunological and biological activity of serum luteinizing hormone during the bovine estrous cycle



Domestic Animal Endocrinology 3(1): 1-10



Although immunological luteinizing hormone (LH) profiles have been extensively characterized in several species, an awareness has developed that these immunological LH measurements may not adequately describe the biological activity or stimulation of the target tissue. The objective of this study was to compare serum LH at different stages of the bovine estrous cycle as measured by both bioassay and radioimmunoassay. Blood samples were collected from 5 cows at 10 min intervals for 10 hr on days 3, 10 and 19 of the estrous cycle; for 24 hr at estrus on day 0 (natural preovulatory LH surge, NS); and for 8 hr following administration of luteinizing hormone-releasing hormone (induced LH surge) on day 10 of that cycle. Immunological activity of LH was determined by a previously validated radioimmunoassay. A sensitive and specific in vitro mouse Leydig cell bioassay in which testosterone production was an index of added LH was used to assess biological activity of LH. The same preparation (NIAMDD-bLH-4) served as the standard for each assay system. Patterns of biological active LH closely followed those of immunological LH, although biological LH values tended to be lower. Although the pulse frequency (pulses/hr) of immunological LH was lower (P < 0.5) on day 10 (.48 .+-. 0.7; .hivin.x .+-. SE) than day 3 or 19 (.88 .+-. .09 and .88 .+-. .15, respectively), no changes in biological LH pulse frequency were noted (P > .05). The mean biological to immunological (B:I) ratios were greater (P < .05) on days 3 and 10 (0.91 .+-. 1.6 and 0.93 .+-. .12, respectively) than day 19 (0.64 .+-. .05) and day 0 (0.43 .+-. .07). The B:I ratios of the natural LH surge and induced LH surge were not different from each other (P > .05). These observations demonstrate that biological LH exhibits a pattern similar to, but not identical to, immunological LH. Furthermore, as evidenced by changing B:I ratios, the pituitary releases LH which is not of the same biological activity at all stages of the estrous cycle. These data suggest that both quality and quantity of LH released may be important in regulating LH action at the target tissue.

(PDF emailed within 0-6 h: $19.90)

Accession: 001336020

Download citation: RISBibTeXText

DOI: 10.1016/0739-7240(86)90034-2



Related references

Simultaneous determination of luteinizing hormone activity in blood serum of sheep during 3 synchronized estrous cycles by biological and radio immunological method. Endokrinologie 67(1): 1-7, 1976

Biologically active luteinizing hormone in plasma 5. a reanalysis of the differences in the ratio of biological to immunological luteinizing hormone activities during the menstrual cycle. Acta Endocrinologica 92(4): 615-626, 1979

Serum progesterone and luteinizing hormone levels during the bovine estrous cycle. Endocrinology 88(3): 678-686, 1971

Biological activity of luteinizing hormone (LH) during the estrous cycle of mares. Domestic Animal Endocrinology 3(2): 69-77, 1986

Hypothalamic luteinizing hormone releasing factor pituitary luteinizing hormone luteal progestin and reproductive tract changes during the bovine estrous cycle. Proceedings International Congress On Animal Reproduction & Artificial Insemination: 63, 1968

The day to day rhythm of luteinizing hormone activity in the serum of sheep after synchronized estrous cycle. Pigon, Halina, M Tischner And J Pilch (Ed ) Proceedings Of The International Congress on Animal Reproduction And Artificial Insemination, Viiith Vol 1 Communication Abstracts; Vol 2 Plenary Papers; Vol 3 The Physiology Of Reproduction (Selected Papers); Vol 4 The Pathology Of Reproduction And Artificial Insemination (Selected Papers); And Vol 5 Final Report Krakow, Poland, July 12-16, Xix+349p(Vol 1); Iii+52p(Vol 3); 585p(Vol 4); 250p(Vol 5) Illus Polish Academy, 1976

Biologically active luteinizing hormone (LH) in plasma. V. A re-analysis of the differences in the ratio of biological to immunological LH activities during the menstrual cycle. Acta Endocrinologica 92(4): 615-626, 1979

Lemur spp show differences in immunological and biological activity of luteinizing hormone. Folia Primatologica 57(3): 173-176, 1991

Temporal changes in medial basal hypothalamic luteinizing hormone releasing hormone correlated with plasma luteinizing hormone during the rat estrous cycle and following electrochemical stimulation of the medial preoptic area in pento barbital treated pro estrous rats/. Brain Research 148(2): 413-424, 1978

Lemur species show differences in immunological and biological activity of luteinizing hormone. Folia Primatologica; International Journal of Primatology 57(3): 173-176, 1991

Relationship between ovarian delta 5 3 beta hydroxy steroid dehydrogenase activity and serum luteinizing hormone and fsh levels during the estrous cycle in the mouse. Journal of the Faculty of Science University of Tokyo Section IV Zoology 15(2): 247-254, 1982

A new concept for control of the estrous cycle of the ewe based on the temporal relationships between luteinizing hormone estradiol and progesterone in peripheral serum and evidence that progesterone inhibits tonic luteinizing hormone secretion. Endocrinology 101(3): 807-817, 1977

Radio immunological determination of luteinizing hormone in the hypophysis and blood during the estrous cycle in rats. Problemy Endokria 21(4): 63-66, 1975

Effects of luteinizing hormone lh prolactin prl and prostaglandin f 2 alpha pgf on hormone secretion by bovine luteal cells at different stages of the estrous cycle. Journal of Animal Science 65(SUPPL 1): 364, 1987