Isolation of Canine Prolactin by Polyacrylamide Gel Electrophoresis

Jones, Gwyneth E.; Boyns, A. R.

doi:10.1530/acta.0.0820691

Cited by 14 publications

(6 citation statements)

References 12 publications

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“…Canine and ovine PRL are similar in molecular size, amino acid composition, physical properties and biological activity (27)(28)(29), and ovine PRL has been shown to stimulate canine mammary tissue (30), as well as P secretion in the present study. Therefore, it is unlikely that the failure of ovine PRL to stimulate Rlx production is due to a species incompatability.…”

Section: Weeks Of Pregnancysupporting

confidence: 62%

Diurnal Variation of Serum Progesterone, but Not Relaxin, Prolactin, or Estradiol-17β in The Pregnant Bitch*

et al. 1990

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The concentrations of progesterone (P), relaxin (Rlx), estradiol (E2) and PRL were measured by specific RIAs in serum samples collected twice daily at 8:00 am and 3:00 pm at weekly intervals after mating and until whelping in five Labrador Retriever bitches. From weeks 3 to 6 of pregnancy, P exhibited a conspicuous and statistically significant diurnal pattern (P less than 0.05), its serum concentration being approximately twice as high at 8:00 am as at 3:00 pm. A similar but nonsignificant trend was observed weeks 2, 7, and 8, and the overall ratio of the am/pm P concentrations was 2.4 +/- 0.28 (P less than 0.001). Rlx, E2, and PRL did not show a diurnal pattern at any time during pregnancy. The glandular sources and regulation of secretion of Rlx were further investigated. Rlx bioactivity was detected in canine placentas and ovaries, providing supportive evidence that these organs may be a dual source of the hormone in canine pregnancy. Injection of ovine PRL in three pseudopregnant bitches significantly increased serum P concentration as compared with seven untreated pseudopregnant controls, but Rlx was not detectable in serum before, during or after PRL treatment. The data support the view that Rlx and P are independently regulated in the bitch; PRL may be a regulator of P, but not of Rlx secretion. However, as PRL showed no diurnal changes in concentration, it does not appear to be directly responsible for the diurnal pattern exhibited by P.

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Section: Weeks Of Pregnancysupporting

confidence: 62%

Diurnal Variation of Serum Progesterone, but Not Relaxin, Prolactin, or Estradiol-17β in The Pregnant Bitch*

et al. 1990

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“…During pregnancy the progesterone concentrations remain maximal up to about Day 35 before waning steadily to give basal levels by the time of parturition or during the early stages of lactation (Austad, Lunde &Sjaastad, 1976;Concannon et al, 1975;Hadley, 1975 b;Smith & McDonald, 1974;Jones, Boyns, Bell, Christie & Parkes, 1973c;Masken, 1972;Christie, Bell, Horth & Palmer, 1971 ;Bell, Christie & YoungLai, 1971). Jones et al (1976) found increased plasma prolactin levels on the last day of pro-oestrus, but we were unable to find any clear changes in serum prolactin concentrations with thestageof the cycle. This was probably due to the times of blood sampling which were not frequent enough to detect shortterm hormonal changes around ovulation.…”

Section: Pregnancycontrasting

confidence: 55%

“…As found by Jones et al (1976) andGraf et al (1977) serum prolactin concentrations increase steadily during the last half of pregnancy and reach high concentrations during early lactation. The present study supplements these findings and shows that during the later stages of lactation, from about Day 84 onwards (related to the first day of copulation), prolactin levels waned steadily until cessation of lactation.…”

Section: Pregnancymentioning

confidence: 63%

“…A predominant role of progestagens in the stimulation of prolactin and growth hormone synthesis and/or secretion has therefore been suggested (Neumann & Elger, 1972). Only one preliminary report on radioimmunoassayable canine prolactin has been published (Jones, Brownstone & Boyns, 1976). A specific homologous radioimmunoassay for canine prolactin has now been developed (Graf, Friedreich, Matthes & Hasan, 1977) The blood was collected by venepuncture between 07:00 and 10:00 h (regardless of the time of suckling), allowed to clot for about 4 h at 4°C and centrifuged at 3000 g for 10 min.…”

Section: Introductionmentioning

confidence: 99%

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Serum oestrogen, progesterone and prolactin concentrations in cyclic, pregnant and lactating beagle dogs

Gräf¹

1978

Reproduction

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Summary. No correlations between the three hormones measured were found in any of the reproductive states examined. In 2 out of 8 dogs a negative correlation between serum progesterone and prolactin levels was found at Day 11 and Day 15, respectively (Day 0 = first day of copulation). In all of the 8 animals in which the progesterone and prolactin concentrations were measured in the same samples in late pregnancy, a negatively correlated overall pattern was obtained between both hormone profiles. No correlation between serum oestrogen and prolactin levels was found.It is concluded that the proliferative mammary gland changes which are induced in female dogs during long-term toxicity testing with progestagens are unlikely to be related to prolactin or oestrogen synthesis and/or secretion.

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“…Our group also previously showed that most of the cPRL activity remained in the precipitate [31]. This PRL-rich fraction can be efficiently used for further purification [30,32,33]. Con A Sepharose affinity chromatography was used as the first step in the isolation of cLH, cFSH and cTSH from the supernatant fluid.…”

Section: Discussionmentioning

confidence: 99%

Isolation and Partial Characterization of LH, FSH and TSH from Canine Pituitary Gland.

1997

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Abstract. A new preparative procedure without using ion-exchanger is described for the efficient purification of canine LH (cLH), FSH (cFSH) and TSH (cTSH) from the pituitary gland. The hormones were extracted from the pituitary homogenate with an ammonium sulfate solution, and were separated by Concanavalin (Con) A affinity-, hydrophobic interaction-, then immobilized metal ion affinity chromatography.In the immobilized metal ion affinity chromatography, we used copper (Cu2+) as chelated metal ion with ammonium ion gradient and pH gradient in phosphate buffer to attain separation of the hormones. High purity of cLH, cFSH and cTSH was indicated as single bands in SDS-PAGE, with apparent molecular masses of 34, 36 and 37 kDa, respectively.The purified hormones showed two bands corresponding to a (20 kDa) and f3 subunits (cLHJ3:16 kDa, cFSHJJ: 22 kDa, cTSHJJ:16 kDa) under reducing condition in SDS-PAGE. The purified hormones were prepared in good recovery (LH: 53%, FSH: 34%, TSH: 36%) with high biological activity or binding activity to the receptor. Crosscontamination of the purified hormone was less than 0.5%. Examination of the hormone fraction with isoelectric focusing showed that major peaks of isoelectric isoforms were maintained throughout the purification steps of cLH and cFSH, while a few peaks were lost in Con A affinity chromatography in cTSH purification. It was concluded that the present method could prepare highly purified cLH, cFSH and cTSH which retained isoforms of the hormones and biological activity or binding affinity to the receptor.

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Isolation of Canine Prolactin by Polyacrylamide Gel Electrophoresis

Cited by 14 publications

References 12 publications

Diurnal Variation of Serum Progesterone, but Not Relaxin, Prolactin, or Estradiol-17β in The Pregnant Bitch*

Diurnal Variation of Serum Progesterone, but Not Relaxin, Prolactin, or Estradiol-17β in The Pregnant Bitch*

Serum oestrogen, progesterone and prolactin concentrations in cyclic, pregnant and lactating beagle dogs

Isolation and Partial Characterization of LH, FSH and TSH from Canine Pituitary Gland.

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