Evidence for Homology Between Ovine and Human Placental Lactogens

Handwerger, Stuart; Maurer, W; Barrett, Janet R; Hurley, Thomas W.; Fellows, Robert E.

doi:10.3109/07435807409053835

Cited by 41 publications

(21 citation statements)

References 8 publications

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“…The distribution of oPL binding to rabbit tissues (Table 3) closely parallels the distribution of prolactin receptors reported by Posner et al (17). (29). Similarly, the ability of bPL to displace 125I-labeled bGH is only 50% of its ability to displace 125I-labeled bPR in their respective target organs (13).…”

Section: Discussionsupporting

confidence: 82%

“…A dissociation between binding and active sites has been established for corticotropin (31). Although the subprimate placental lactogens appear to bind preferentially to the prolactin receptor, there is also some cross-binding to specific growth hormone receptors (13,29). Thus, the biological effects of these hormones may reside in a balance between the activation of the two receptors, much in the same manner as the differential effects of sympathomimetic drugs depend upon their relative potencies at a and , adrenergic receptors (32).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Localization and specificity of binding of subprimate placental lactogen in rabbit tissues.

Bolander¹,

Hurley²,

Handwerger³

et al. 1976

Proc. Natl. Acad. Sci. U.S.A.

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A search for specific placental lactogen binding was undertaken in tissues obtained from late pregnant rabbits using the placental lactogens from sheep, cows, and human beings. 125I-labeled ovine lactogen exhibited highest specific binding to the adrenal gland (57.8%), followed by liver (21.5%), ovary (19.9%), mammary gland (15.9%), uterus (12.2%), kidney (8.8%), brain (8.5%), and adipose tissue (7.9%). In liver and mammary gland, the displacement curves for ovine and human lactogen were identical to that for bovine prolactin, indicating that they share the same receptor site. Although the displacement curve for bovine lactogen was parallel to that of the other lactogens the bovine hormone is less active in the radioreceptor assay.

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Section: Discussionsupporting

confidence: 82%

Section: Discussionmentioning

confidence: 99%

Localization and specificity of binding of subprimate placental lactogen in rabbit tissues.

Bolander¹,

Hurley²,

Handwerger³

et al. 1976

Proc. Natl. Acad. Sci. U.S.A.

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“…sheep (Handwerger, Maurer, Barrett, Hurley & Fellows, 1974;Hurley, Maurer, Handwerger & Fellows, 1975;Martal & Djiane, 1975;Chan, Robertson & Friesen, 1976;Fellows, Bolander, Hurley & Handwerger, 1976), cow (Bolander & Fellows, 1976a) and rabbit (Bolander & Fellows, 19766).…”

Section: Introductionmentioning

confidence: 96%

Purification and Some Properties of Ovine Placental Lactogen

Reddy¹,

Watkins²

1978

Journal of Endocrinology

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A method has been described for the purification of ovine placental lactogen (oPL) involving the use of freshly obtained sheep foetal cotyledons. Tissue was extracted with 0.1 M-ammonium bicarbonate and the supernatant fraction, adjusted to pH 7, was brought to 60% saturation with ammonium sulphate. The resulting precipitate was then subjected to a sequence of chromatographic steps using columns of Sephadex G-100 and carboxymethylecellulose. During each stage of the purification, the lactogenic activity was monitored with a pregnant rabbit mammary gland radioreceptor assay. The yield of oPL corresponded to 8 mg/kg wet foetal tissue and the oPL possessed lactogenic activity equivalent to 1 mg ovine prolactin/mg protein and GH-like activity equivalent to 0.8 mg human GH/mg protein. The biological activity of oPL was confirmed using a rabbit intraductal mammary gland assay in vivo. After polyacrylamide gel electrophoresis at pH 8.9, oPL was resolved into one major band (isoelectric point 8.2--8.4) and four minor components, which were thought to be deamidation products of oPL. Microimmunoelectrophoresis and immunodiffusion studies confirmed that the preparation of oPL was free from serum protein contaminants.

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“…A lactogenic hormone of placental origin (placental lactogen) has been identified in sheep (Handwerger, Maurer, Barrett, Hurley & Fellows, 1974); this hormone presents a low and stable binding during pregnancy which is independent of prolactin receptor concentrations (Chan et al, 1978). The results described above suggest that ovine placental lactogen may have a direct action on luteal cells since this hormone binds to luteal membranes.…”

Section: Sowmentioning

confidence: 78%