Dopamine in hypophysial portal blood: relationship to circulating prolactin in pregnant and lactating rats.

The relationship between dopamine (DA) concentration in hypophysial portal blood and that of PRL in systemic blood during gestation and lactation was investigated. PRL level in plasma collected by decapitation was low during the 18–21 days of gestation, increased on day 22, and remained elevated throughout the first 10 days of lactation. Separation of mothers from pups for 24 h resulted in a marked reduction in plasma PRL concentration. DA, but not norepinephrine or epinephrine, was higher in portal than in arterial plasma in all rats. DA in portal plasma of 18- to 21-day pregnant rats [4.9 ± 0.7 ng/ ml, (mean ± SEM)] was significantly higher than that in portal plasma from 1- to 5- and 6- to 10-day lactating rats (2.9 ± 0.3 and 2.7 ± 0.4 ng/ml, respectively). Separation of mothers from pups for 24 h resulted in a significant elevation of portal plasma dopamine compared with separation for 30 min. No differences were found in hypothalamic, anterior, or posterior pituitary catecholamine concentrations as a...

[1]  S. Chiocchio,et al.  Involvement of adenohypophysial dopamine in the regulation of prolactin release during suckling. , 1979, Endocrinology.

[2]  L. Frohman,et al.  Prolactin-suppressive effects of two aminotetralin analogs of dopamine: their use in the characterization of the pituitary dopamine receptor. , 1979, Endocrinology.

[3]  J. C. Porter,et al.  Estrogen inhibition of dopamine release into hypophysial portal blood. , 1979, Endocrinology.

[4]  J. Roberts,et al.  Dopamine and dihydroergocryptine binding to the anterior pituitary and other brain areas of the rat and sheep. , 1978, Endocrinology.

[5]  P. Plotsky,et al.  Liquid chromatographic-electrochemical measurement of dopamine in hypophysial stalk blood of rats. , 1978, Endocrinology.

[6]  J. D. Neill,et al.  Dopamine levels in hypophysial stalk blood in the rat are sufficient to inhibit prolactin secretion in vivo. , 1978, Endocrinology.

[7]  R. Macleod,et al.  Binding of dopamine to bovine anterior pituitary gland membranes. , 1978, Neuroendocrinology.

[8]  G. Goldhaber,et al.  Suppression of prolactin and thyrotropin secretion in the rat by antiserum to thyrotropin-releasing hormone. , 1977, Endocrinology.

[9]  J. Ondo,et al.  The effects of gamma-aminobutyric acid on prolactin and gonadotropin secretion in the unanesthetized rat. , 1977, Endocrinology.

[10]  A. Schally,et al.  Isolation of gamma-amino butyric acid from pig hypothalami and demonstration of its prolactin release-inhibiting (PIF) activity in vivo and in vitro. , 1977, Endocrinology.

[11]  C. Oliver,et al.  Dopamine in hypophysial portal plasma of the rat during the estrous cycle and throughout pregnancy. , 1977, Endocrinology.

[12]  G. Brown,et al.  Dopamine/neuroleptic receptors in basal hypothalamus and pituitary. , 1976, Endocrinology.

[13]  V. Garsky,et al.  Enkephalin-stimulated prolactin release. , 1976, Life sciences.

[14]  A. Frantz,et al.  Suppression of prolactin secretion by L-dopa in the stalk-sectioned rhesus monkey. , 1976, The Journal of clinical endocrinology and metabolism.

[15]  N. Ben-Jonathan,et al.  A sensitive radioenzymatic assay for dopamine, norepinephrine, and epinephrine in plasma and tissue. , 1976, Endocrinology.

[16]  B. Goldman,et al.  Ovarian control of prolactin secretion during late pregnancy in the rat. , 1975, Endocrinology.

[17]  J. Clemens,et al.  The role of catecholamines in the release of anterior pituitary prolactin in vitro. , 1974, Endocrinology.

[18]  J. Takahara,et al.  Suppression of prolactin release by a purified porcine PIF preparation and catecholamines infused into a rat hypophysial portal vessel. , 1974, Endocrinology.

[19]  R. Macleod,et al.  Studies on the mechanism of the dopamine-mediated inhibition of prolactin secretion. , 1974, Endocrinology.

[20]  S. Ojeda,et al.  A rapid and simple procedure for chronic cannulation of the rat jugular vein. , 1974, Journal of applied physiology.

[21]  R. W. Turkington,et al.  Stimulation of human prolactin secretion by intravenous infusion of L-tryptophan. , 1973, The Journal of clinical investigation.

[22]  G. Pepe,et al.  Serum luteinizing hormone, prolactin and progesterone levels during pregnancy in the rat. , 1973, Endocrinology.

[23]  C. Bowers,et al.  Further evidence that TRH is also a physiological regulator of PRL secretion in man. , 1973, Biochemical and biophysical research communications.

[24]  K. Lu,et al.  Effects of L-dopa on serum prolactin and PIF in intact and hypophysectomized, pituitary-grafted rats. , 1972, Endocrinology.

[25]  J. D. Neill.  Comparison of plasma prolactin levels in cannulated and decapitated rats. , 1972, Endocrinology.

[26]  J. Meites,et al.  Mechanisms of pentobarbital actions on prolactin release. , 1971, Endocrinology.

[27]  J. C. Porter,et al.  Effects of melatonin and serotonin on the release of FSH and prolactin. , 1971, Endocrinology.

[28]  J. Meites,et al.  Effects of Ether and Pentobarbital on Serum Prolactin and LH Levels in Proestrous Rats , 1970, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[29]  J. Meites,et al.  Serum prolactin levels in rats during different reproductive states. , 1970, Endocrinology.

[30]  J. C. Porter,et al.  Collection of hypophysial stalk blood in rats. , 1967, Endocrinology.

[31]  J. Meites,et al.  Estrogen stimulation of prolactin production by rat adenohypophysis in vitro. , 1962, Endocrinology.

[32]  O. H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.