Molecular Biology of Growth-Hormone-Secreting Human Pituitary Tumours: Biochemical Consequences and Potential Clinical Significance

ABSTRACT Since growth hormone (GH) and prolactin (Prl) secretion by human pituitary tumours is often influenced by the hypophysiotrophic hormones thyrotrophin-releasing hormone (TRH) and somatostatin (SRIF), we have examined the responses of several transplantable rat pituitary tumours to these substances in a perifusion apparatus. The MStT/W15 tumour did not alter its secretion of GH and Prl in response to TRH, SRIF, or a partially purified porcine hypothalamic extract containing GH-releasing activity; normal rat pituitaries show clear responses to each of these substances. Theophylline and dibutyryl cyclic AMP each provoked increased GH and Prl release from the tumour. A second specimen of the MStT/W15 tumour and a specimen of the MStT/W5 tumour behaved in a manner identical to the original MStT/W15, showing no response to TRH or SRIF, but releasing both GH and Prl when theophylline or dibutyryl cyclic AMP was given. The MtT/F4 tumour increased its secretion of GH in response to TRH, 10 μg/ml, and theophylline, but no effect was seen with lower concentrations of TRH or with SRIF; Prl secretion by the F4 tumour was increased by theophylline, but TRH and SRIF had no effect. The autonomy demonstrated in these experimental tumours may be due to a loss of specific hypophysiotrophic hormone receptors or of secretory activating mechanisms.

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Neuronal nitric oxide synthase gene expression in human pituitary tumours: a possible association with somatotroph adenomas and growth hormone-releasing hormone gene expression

Clinical Endocrinology ◽

10.1046/j.1365-2265.1998.00399.x ◽

1998 ◽

Vol 49 (1) ◽

pp. 29-38 ◽

Cited By ~ 12

Author(s):

Yoichi Ueta ◽

Andrew Levy ◽

Michael P. Powell ◽

Stafford L. Lightman ◽

Yoshimasa Kinoshita ◽

...

Keyword(s):

Gene Expression ◽

Nitric Oxide ◽

Growth Hormone ◽

Nitric Oxide Synthase ◽

Neuronal Nitric Oxide Synthase ◽

Growth Hormone Releasing Hormone ◽

Pituitary Tumours ◽

Human Pituitary ◽

Releasing Hormone ◽

Oxide Synthase

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BROMOCRIPTINE INHIBITS PROLACTIN AND GROWTH-HORMONE RELEASE BY HUMAN PITUITARY TUMOURS IN CULTURE

The Lancet ◽

10.1016/s0140-6736(77)90219-7 ◽

1977 ◽

Vol 310 (8030) ◽

pp. 197-198 ◽

Cited By ~ 34

Author(s):

K MASHITER

Keyword(s):

Growth Hormone ◽

Hormone Release ◽

Growth Hormone Release ◽

Pituitary Tumours ◽

Human Pituitary

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GROWTH HORMONE CONCENTRATION IN HUMAN PITUITARY TUMOURS

Journal of Endocrinology ◽

10.1677/joe.0.0450133 ◽

1969 ◽

Vol 45 (1) ◽

pp. 133-134 ◽

Cited By ~ 5

Author(s):

H. M. LLOYD ◽

K. J. DONALD ◽

K. J. CATT ◽

H. G. BURGER

Keyword(s):

Growth Hormone ◽

Hormone Concentration ◽

Pituitary Tumours ◽

Human Pituitary ◽

Growth Hormone Concentration

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THE EXTRACTION OF PROLACTIN FROM HUMAN PITUITARY GLANDS

Acta Endocrinologica ◽

10.1530/acta.0.0490001 ◽

1965 ◽

Vol 49 (1) ◽

pp. 1-16 ◽

Cited By ~ 12

Author(s):

M. Apostolakis

Keyword(s):

Growth Hormone ◽

Pituitary Gland ◽

List Type ◽

Distilled Water ◽

Hormone Activity ◽

Isoelectric Precipitation ◽

Human Pituitary ◽

Pituitary Glands ◽

Prolactin Content ◽

The Mean

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.

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