Fractionation of Human Pituitary Glands

Wilhelmi, Alfred E.

doi:10.1139/o61-183

Cited by 77 publications

(20 citation statements)

References 8 publications

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“…Despite the difficulties which have been experienced in attempts to isolate a human prolactin separate from growth hormone (12)(13)(14), evidence from several sources has previously suggested that such a hormone does in fact exist: nonpuerperal galactorrhea in humans is not usually associated with signs of acromegaly (39,43). Growth hormone levels are not elevated in nursing mothers during the puerperium (44)(45)(46).…”

Section: Discussionmentioning

confidence: 99%

“…Strong lactogenic activity has been associated with highly purified human growth hormone preparations (9)(10)(11). Despite several attempts to isolate a separate human prolactin, no preparation in which growth hormone and prolactin activities are completely dissociated has yet been achieved (12)(13)(14), and the existence of a separate human prolactin has been seriously doubted (15). The problem is further complicated by the limitations of sensitivity and specificity of the conventional pigeon crop-sac assay when the latter is applied to human blood.…”

Section: Introductionmentioning

confidence: 99%

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Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Kleinberg¹,

Frantz²

1971

J. Clin. Invest.

103

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A B S T R A C T Prolactin has been measured in unex-tracted human plasma by a sensitive and specific in vitro bioassay. Secretory activity of breast tissue fragments from mid-pregnant mice, incubated in organ culture with human plasma, serves as the histologic end point.Sensitivity is 5 ng/ml (0.14 mU/ml) or somewhat better for ovine prolactin, and approximately 0.42 mU/ml for prolactin activity of human plasma at the dilutions used in the assay. Human growth hormone as it circulates in blood, like the material extracted from pituitary glands, is strongly lactogenic. Antisera to human growth hormone are capable of completely neutralizing the prolactin effect of large amounts (600 ng/ml) of human growth hormone added to the system. Plasma prolactin activity is less than 0.42 mU/ml in normal men and women. Of 26 patients with nonpuerperal galactorrhea, 14 had elevated prolactin activities ranging from 0.42 to 3.5 mU/ml. Growth hormone levels by radioimmunoassay were far too low, in general, to account for the observed prolactin activity. All of 14 nursing mothers, 1-30 days post partum, had elevated prolactin activity with a mean of 2.29 and a total range of 0.56-4.5 mU/mi.Growth hormone was in the low normal range in all of these subjects. Seven patients on psychoactive drugs of the phenothiazine series similarly had elevated prolactin activity with low growth hormone. Antiserum to human growth hormone, when preincubated with plasma samples from each of these three groups of subjects, produced no significant inhibition of prolactin activity. In two acromegalic patients with markedly elevated growth hormone levels, antiserum to growth hormone produced complete inhibition of prolactin activity in one and partial inhibition in the other. These studies indicate that human growth hormone and human prolactin This work was presented in part at

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Kleinberg¹,

Frantz²

1971

J. Clin. Invest.

103

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“…Following the method of Stockell Hartree (1966) the pituitary glands were first mixed with the extraction medium (6% w/v ammonium acetate in 40% v/v ethanol, pH 5-1; 8 ml/g pituitary wet weight, Wilhelmi (1961)) and homogenised for 15 min at 4 °G in a Waring blendor. The resulting mixture was then stirred for 48 h at 4 °C.…”

Section: Purification Of Lh Fsh and Tshmentioning

confidence: 99%

Fractionation and assay of chicken pituitary hormones

Scanes

Follett

1972

British Poultry Science

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“…Two separate peptides associated with growth-promoting and prolactin like bioactivities, respectively, were suggested as the simplest interpretation from the enrichment in prolactin-like activity in fractions obtained from preparations of HGH [31,32], or from fresh frozen human pituitaries [1]. However, from immunological studies [31] and from a radioimmunoassay of lactating plasma for this material [13,30] it was apparent that growth hormone had become modified, probably by a conformational change, dur ing isolation causing a major change in its biological spectra but essentially minor changes in its immunoreactivity.…”

Section: Introductionmentioning

confidence: 99%

Radioimmunoassay of a Human Pituitary Prolactin in Plasma

Bryant¹,

Siler²,

Greenwood³

et al. 1971

Horm Res Paediatr

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A protein fraction with prolactin bioactivities was obtained from the culture medium of human fetal pituitary tissue in long term cultures and termed Pasteels human prolactin (PHP) for convenience. An antiserum was prepared against this human prolactin and used to develop a radioimmunoassay for the material in human plasma. The antigen available (220 µg)was tested against antisera to human growth hormone and to human placental lactogen and in radioimmunoassays for these hormones. The results suggested that the human prolactin fraction contained some immunoreactive human growth hormone (1%). The resulting antibodies in the antihuman prolactin serum could be neutralized by the addition of human growth hormone. The human prolactin also generated antibodies, binding ¹³¹I-labelled human prolactin, which were not neutralized by human growth hormone. This binding was inhibited by plasma from a normal male, 2 normal females and by plasma from a lactating woman after breast feeding. An increase in plasma concentration of the inhibitor, immunologically similar to the human prolactin fraction, was obtained after phenothiazine injection. In the 7 plasma samples tested for human prolactin only 1 contained a detectable concentration of immunoreactive growth hormone. Immunoreactive human placental lactogen (human chorionic somatomammotropin) or any material cross-reacting with anti-HCS serum was undetectable in these plasma samples by a sensitive radioimmunoassay. It is suggested that human plasmas contain detectable amounts of a material immunologically similar to a prolactin fraction isolated from tissue cultures of fetal pituitaries. The fraction and the plasma inhibitor are distinguishable by immunoassay from human growth hormone and from human placental lactogen.

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Fractionation of Human Pituitary Glands

Cited by 77 publications

References 8 publications

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Fractionation and assay of chicken pituitary hormones

Radioimmunoassay of a Human Pituitary Prolactin in Plasma

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