EFFECTS OF PIMOZIDE AND BROMOCRIPTINE ON THE PROLIFERATION OF RAT PITUITARY PARS INTERMEDIA CELLS

1977 ◽  
Vol 75 (3) ◽  
pp. 443-444 ◽  
Author(s):  
J. RYCHTER ◽  
H. STEPIEŃ
Keyword(s):  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Mitotic Activity ◽  
Secretory Cells ◽  
Pars Intermedia ◽  
Dopamine Receptor Agonist ◽  
Intermediate Lobe ◽  
Melanocyte Stimulating Hormone ◽  
Medical Academy ◽  
Rat Pituitary

Department of Experimental Endocrinology, Institute of Endocrinology, Medical Academy of Łódź, Dr. Sterling str. 3, 91-425 Łódź, Poland (Received 31 May 1977) The secretory function of the intermediate lobe of the pituitary gland is under hypothalamic control (Howe, 1973; Hadley & Bagnara, 1975). Penny, Thody, Tilders & Smelik (1977) have suggested that the synthesis and release of melanocyte-stimulating hormone (MSH) is mediated by dopaminergic neurones which make synaptic contact with secretory cells in the pars intermedia (Björklund, Moore, Nobin & Stenevi, 1973). We have attempted to examine whether the dopaminergic mechanism is also involved in the control of the mitotic activity of the pars intermedia cells and have studied the effects of pimozide, a dopamine receptor blocker (Anden, Butcher, Corrodi, Fuxe & Ungerstedt, 1970) and 2-bromo-α-ergocriptine (bromo-criptine), a dopamine receptor agonist (Loew, Vigouret & Jaton, 1976) on the mitotic activity of the pars intermedia of the rat pituitary gland. Twenty-three

DIRECT ANTIPROLIFERATIVE EFFECT OF DOPAMINE AGONISTS ON THE ANTERIOR PITUITARY GLAND IN ORGAN CULTURE

1978 ◽  
Vol 79 (2) ◽  
pp. 245-246 ◽  
Author(s):  
M. PAWLIKOWSKI ◽  
J. KUNERT-RADEK ◽  
H. STĘPIEŃ
Keyword(s):  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Mitotic Activity ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland ◽  
Antiproliferative Effect ◽  
Male Rats ◽  
Pars Intermedia ◽  
Pituitary Tumours ◽  
Rat Pituitary

Department of Experimental Endocrinology, Institute of Endocrinology, Medical Academy of Łódź, Dr Sterling sir. 3, 91–425 Łódź, Poland (Received 22 May 1978) Lloyd, Meares & Jacobi (1975) observed inhibition of mitotic activity in the anterior pituitary gland by the dopamine receptor agonist, bromocriptine, in oestrogen-treated male rats. This observation has been confirmed in our laboratory (Stępień, Wolaniuk & Pawlikowski, 1978). Suppression of mitotic activity in the pars intermedia of the rat pituitary gland by bromocriptine has also been observed (Rychter & Stępień, 1977). Furthermore, it has been found that the dopamine receptor blocker, pimozide, enhances mitotic activity in the rat anterior pituitary gland (Stępień et al. 1978). By the use of various ergot alkaloids, MacLeod & Lehmeyer (1973) succeeded in inhibiting the growth of transplantable rat pituitary tumours. There have also been observations suggesting an antiproliferative effect of bromocriptine on human pituitary tumours (Wass, Thorner, Morris, Rees, Mason, Jones &

Desensitization of the D-2 dopamine receptor and the β2-adrenoceptor in the intermediate lobe of the rat pituitary gland

1983 ◽  
Vol 5 (6) ◽  
pp. 803-810 ◽  
Author(s):  
K. Miyazaki ◽  
J.M. Saavedra ◽  
T.E. Cote ◽  
J.W. Kebabian
Keyword(s):  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Intermediate Lobe ◽  
Rat Pituitary

The D-2 Dopamine Receptor in the Intermediate Lobe of the Rat Pituitary Gland

1983 ◽  
pp. 33-72 ◽  
Author(s):  
J. W. KEBABIAN ◽  
M. BEAULIEU ◽  
T. E. COTE ◽  
R. L. ESKAY ◽  
E. A. FREY ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Intermediate Lobe ◽  
Rat Pituitary

The Dopamine Receptor in the Intermediate Lobe of the Rat Pituitary Gland

1982 ◽  
pp. 327-340
Author(s):  
M. Munemura ◽  
T. Cote ◽  
R. Eskay ◽  
E. Frey ◽  
C. Grewe ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Intermediate Lobe ◽  
Rat Pituitary

The Dopamine Receptor in the Intermediate Lobe of the Rat Pituitary Gland: Pharmacological Characterization

Endocrinology ◽  
1980 ◽  
Vol 107 (6) ◽  
pp. 1676-1683 ◽  
Author(s):  
M. MUNEMURA ◽  
T. E. COTE ◽  
K. TSURUTA ◽  
R. L. ESKAY ◽  
J. W. KEBABIAN ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Intermediate Lobe ◽  
Pharmacological Characterization ◽  
Rat Pituitary

Beta-adrenergic stimulation of the release of ACTH- and LPH-related peptides from the pars intermedia of the rat pituitary gland

1981 ◽  
Vol 97 (3) ◽  
pp. 343-351 ◽  
Author(s):  
F.J. H. Tilders ◽  
M. Post ◽  
S. Jackson ◽  
P.J. Lowry ◽  
P. G. Smelik
Keyword(s):  
Pituitary Gland ◽  
Cortical Cell ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Spontaneous Release ◽  
Adrenergic Stimulation ◽  
Similar Time ◽  
In Vitro Superfusion ◽  
Rat Pituitary

Abstract. The intermediate lobe of the rat pituitary gland produces a series of peptides related to ACTH and LPH. The spontaneous and isoproterenol-stimulated release of such peptides was studied during in vitro superfusion of rat neurointermediate lobes with Krebs-Ringer medium. Products released into the superfusion medium were quantified by direct measurement or after chromatography on Sephadex G-50. ACTH bioactivity was determined by use of adrenal cortical cell suspension assay. In addition, NH2-terminal ACTH, CO2H-terminal ACTH, α-MSH and β-endorphin radioimmunoassays were used. The results show that 1. neurointermediate lobes of rats secrete spontaneously various ACTH- and LPH-related peptides in amounts proportional to the amounts in which these peptides are found in extracts of the neurointermediate lobe; 2. the β-adrenergic agonist, isoproterenol, stimulated the spontaneous release of various peptides, including α-MSH, ACTH, CLIP, glycosylated CLIP, and β-endorphin-like peptides; 3. isoproterenol induced a dose-dependent (10−9–10−7 m), parallel increase in the release of α-MSH and ACTH following similar time courses and showing indentical EC50 values (about 10−8 m). Although the spontaneous release of α-MSH and ACTH from rat neurointermediate lobes is not strictly coupled under the conditions used in this study, isoproterenol seems to affect the spontaneous release of these peptides to the same relative extent.

Sign in / Sign up

Export Citation Format

Share Document