Prolactin Activity of Human Growth Hormone

Ferguson, K. A.; Wallace, Andrew L.

doi:10.1038/190632a0

Cited by 77 publications

(12 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Human growth hormone contains the equivalent of 3 or 4 TU prolactin/mg by the pigeon crop assay [8] or the rabbit mammary gland assay [9]. Hence the ' prolactin'/HGH material from tissue culture would be expected to have a prolactin activity due to its human growth hormone content of 0.03-0.04 IU/mg, whereas its bioactivity is 2.95 IU/mg.…”

Section: Discussionmentioning

confidence: 99%

Radioimmunoassay of a Human Pituitary Prolactin in Plasma

Bryant¹,

Siler²,

Greenwood³

et al. 1971

Horm Res Paediatr

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionmentioning

confidence: 99%

Radioimmunoassay of a Human Pituitary Prolactin in Plasma

Bryant¹,

Siler²,

Greenwood³

et al. 1971

Horm Res Paediatr

View full text Add to dashboard Cite

show abstract

“…The evidence in support of this concept has recently been reviewed (1,2). Progress in our understanding of the physiology of human prolactin (HPr) has been impeded by the limitations of most bioassay methods in accurate measurement of normal circulating levels of the hormone, because of insensitivity of assay methods and failure to eliminate the intrinsic crop-sac stimulating (1,3) and mammary stimulating (4-6) activity of the human growth hormone molecule (HGH).…”

mentioning

confidence: 97%

A Mixed Heterologous Radioimmunoassay for Human Prolactin1

Jacobs

Mariz

Daughaday

1972

The Journal of Clinical Endocrinology & Metabolism

101

View full text Add to dashboard Cite

A mixed heterologous radioimmuoassay for human prolactin (HPr) has been developed in which prolactin in serum or plasma competes with radio-iodinated porcine prolactin for binding sites on anti-ovine prolactin antibody. The system is unaffected by all pituitary and placental peptides tested, and allows specific measurement of HPr in unextracted plasma or serum throughout pregnancy and in acromegaly. Sensitivity is sufficient to detect HPr in serum of normal males and females, whose mean levels ( ± SE) were 6.2 ± 0.6 and 9.0 ± 0.6 ng/ml, respectively. Mean HPr levels ( ± SE) during normal pregnancy were 56.2 ± 5.6, 117.4 d= 14.0, and 251.4 =t 23.3 ng/ml in the three successive trimesters. Elevated levels were found in most patients with non-puerperal galactorrhea of various etiologies, and were very high in patients with HPr-secreting pituitary tumors. (/ Clin Endocr 34: 484, 1972) N O DOUBT REMAINS of the existence of a separate human prolactin molecule. The evidence in support of this concept has recently been reviewed (1,2). Progress in our understanding of the physiology of human prolactin (HPr) has been impeded by the limitations of most bioassay methods in accurate measurement of normal circulating levels of the hormone, because of insensitivity of assay methods and failure to eliminate the intrinsic crop-sac stimulating (1,3) and mammary stimulating (4-6) activity of the human growth hormone molecule (HGH).Recently developed bioassay methods utilizing mouse mammary glands in which HGH activity is neutralized immunologically (5,6) have the virtue of increased sensitivity and specificity, but are tedious and time-consuming. Very recently radioimmunoassays of human prolactin have been separately reported from the labora-

show abstract

“…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).…”

Section: Introductionmentioning

confidence: 99%

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Kleinberg¹,

Frantz²

1971

J. Clin. Invest.

103

View full text Add to dashboard Cite

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

show abstract

Prolactin Activity of Human Growth Hormone

Cited by 77 publications

References 1 publication

Radioimmunoassay of a Human Pituitary Prolactin in Plasma

Radioimmunoassay of a Human Pituitary Prolactin in Plasma

A Mixed Heterologous Radioimmunoassay for Human Prolactin1

Human Prolactin: Measurement in Plasma by In Vitro Bioassay

Contact Info

Product

Resources

About