Chemical, biological and immunological properties of pituitary gonadotropins from the donkey (Equus asinus): comparison with the horse (Equus caballus).
Abstract: Donkey gonadotropins (donkey luteinizing hormone, dLH; donkey follicle-stimulating hormone, dFSH) have been isolated in purified form from 191 donkey pituitaries using essentially the same procedures previously employed for the purification of equine gonadotropins. Chemically, dLH and dFSH were observed to be similar to equine LH (eLH) and FSH (eFSH) in fractionation behavior and glycoprotein nature. Two forms of the dFSH molecule were observed, as is the case for eFSH. Donkey LH had significantly less total carbohydrate (13.5%) and sialic acid (1.9%) than eLH (26.7% and 5.8%, respectively). Carbohydrate (17-21%) and sialic acid (2.4%) content of the two dFSH preparations closely resembled that of eFSH. A slightly higher tyrosine content in the donkey gonadotropins was noted in a comparison of amino acid compositions. Immunologically, in a heterologous FSH radioimmunoassay (RIA), dFSH preparations were equal to or twice as active as eFSH preparations. However, in homologous RIAs for equine chorionic gonadotropin (eCG), eFSH and eLH, both the dLH and dFSH preparations were considerably less active than the equine gonadotropins, and their inhibition curves were all nonparallel. Biologically, in the Steelman-Pohley assay both dFSH preparations were equipotent and as potent as eFSH (approximately 40 times NIH-FSH-S12). In the Sertoli cell assay for cAMP (FSH assay) and the Leydig cell assay for testosterone (LH assay), both dFSH and dLH were 2- or 6-fold more active than eFSH and eLH, respectively. In rat and equine testis FSH homologous radioreceptor assays, dFSH preparations were as active and up to 6-fold more active than eFSH. In contrast, dLH was 10-fold less active than eLH in the equine LH homologous radioreceptor assay. Unlike eLH, dLH was found to possess little intrinsic FSH activity or FSH inhibitory activity, and the small amount of FSH activity observed was most likely due to FSH contamination. Therefore, eLH behaves much like eCG (pregnant mare's serum gonadotropin, PMSG) which also possesses both LH and FSH activity. In contrast, dLH behaves more like donkey chorionic gonadotropin (dCG) which possesses only a low degree of FSH activity.
Publication Date: 1984-06-01 PubMed ID: 6329342DOI: 10.1095/biolreprod30.5.1253Google Scholar: Lookup
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- Comparative Study
- Journal Article
- Research Support
- Non-U.S. Gov't
- Research Support
- U.S. Gov't
- P.H.S.
Summary
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The research provides a comparative analysis between the hormonal substances from donkeys and horses and it investigates their chemical, biological, and immunological properties. It reveals that these substances have remarkably different degrees of activity and content levels.
Research Methodology
- The researchers used nearly 200 donkey pituitaries to derive purified form of donkey gonadotropins (dLH and dFSH)
- The purification process used was the same as the one previously used for equine gonadotropins
- The researchers conducted multiple assays and tests to examine chemical, biological, and immunological properties of the isolated gonadotropins
Chemical Properties
- dLH and dFSH were found to be similar to eLH and eFSH in terms of their fractionation behavior and glycoprotein nature
- Two forms of the dFSH molecule were detected, identical to eFSH
- Carbohydrate and sialic acid content of the two dFSH preparations was similar to that of eFSH
- Donkey LH was chemically different from Equine LH as it had significantly less total carbohydrate and sialic acid
- A slightly higher content of tyrosine, an amino acid, was noted in the donkey gonadotropins
Immunological Properties
- In a heterologous FSH radioimmunoassay (RIA), dFSH preparations exhibited equal to or double the activity as compared to the eFSH preparations
- On the contrary, in homologous RIAs for eCG, eFSH and eLH, both the dLH and dFSH were considerably less active
Biological Properties
- As far as the potency is concerned, both dFSH preparations showed equal potency with eFSH
- In the Sertoli cell assay for cAMP (FSH assay) and the Leydig cell assay for testosterone (LH assay), both dFSH and dLH exhibited more activity than their equine counterparts
- In both rat and equine testis FSH homologous radioreceptor assays, dFSH preparations were found to be equal to and more potent than eFSH
- In contrast, dLH was 10-fold less active than eLH in the equine LH homologous radioreceptor assay
Conclusive Findings
- eLH has similarities with eCG as both possess both LH and FSH activity
- In contrast, dLH behaves more like donkey chorionic gonadotropin (dCG) which has a low level of FSH activity
- dLH was found to have little intrinsic FSH or inhibitory activity, and the observed FSH activity was likely due to contamination
Cite This Article
APA
Roser JF, Papkoff H, Murthy HM, Chang YS, Chloupek RC, Potes JA.
(1984).
Chemical, biological and immunological properties of pituitary gonadotropins from the donkey (Equus asinus): comparison with the horse (Equus caballus).
Biol Reprod, 30(5), 1253-1262.
https://doi.org/10.1095/biolreprod30.5.1253 Publication
Researcher Affiliations
MeSH Terms
- Animals
- Biological Assay
- Cross Reactions
- Electrophoresis, Disc
- Follicle Stimulating Hormone / immunology
- Follicle Stimulating Hormone / isolation & purification
- Horses / metabolism
- Luteinizing Hormone / immunology
- Luteinizing Hormone / isolation & purification
- Pituitary Gland / analysis
- Radioimmunoassay
- Rats
- Receptors, Cell Surface / metabolism
- Receptors, FSH
- Receptors, LH
- Species Specificity
Grant Funding
- HD-05722 / NICHD NIH HHS
Citations
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