Abstract
The effects of dopamine on pituitary prolactin secretion and pituitary cyclic AMP accumulation were studied by using anterior pituitary glands from adult female rats, incubated in vitro. During 2h incubations, significant inhibition of prolactin secretion was achieved at concentrations between 1 and 10nm-dopamine. However, 0.1-1mum-dopamine was required before a significant decrease in pituitary cyclic AMP content was observed. In the presence of 1mum-dopamine, pituitary cyclic AMP content decreased rapidly to reach about 75% of the control value within 20min and there was no further decrease for at least 2h. Incubation with the phosphodiesterase inhibitors theophylline (8mm) or isobutylmethylxanthine (2mm) increased pituitary cyclic AMP concentrations 3- and 6-fold respectively. Dopamine (1mum) had no effect on the cyclic AMP accumulation measured in the presence of theophylline, but inhibited the isobutylmethylxanthine-induced increase by 50%. The dopamine inhibition of prolactin secretion was not affected by either inhibitor. Two derivatives of cyclic AMP (dibutyryl cyclic AMP and 8-bromo cyclic AMP) were unable to block the dopamine (1mum) inhibition of prolactin secretion, although 8-bromo cyclic AMP (2mm) significantly st...Continue Reading
Citations
Mar 1, 1983·Clinics in Endocrinology and Metabolism·M J Cronin, W S Evans
Feb 1, 1989·Journal of Neuroendocrinology·J LafondR Collu
Apr 1, 1985·Medicinal Research Reviews·C Kaiser, T Jain
Jan 1, 1989·Journal of Dairy Science·L G Sheffield
Feb 1, 1984·Bioscience Reports·A M BentleyM Wallis
Jun 1, 1987·Journal of Endocrinological Investigation·B VelkeniersL Vanhaelst
Oct 1, 1985·The American Journal of Physiology·J M AndersonM J Cronin
Aug 13, 1984·Life Sciences·J E Merritt, B L Brown
Nov 1, 1982·Molecular and Cellular Endocrinology·K P Ray, M Wallis
Jun 1, 1984·Molecular and Cellular Endocrinology·K P Ray, M Wallis
Jul 1, 1982·Molecular and Cellular Endocrinology·K P Ray, M Wallis
Oct 1, 1982·Molecular and Cellular Endocrinology·M J CroninR M MacLeod
Mar 1, 1986·Molecular and Cellular Endocrinology·J LafondR Collu
Mar 1, 1984·Metabolism: Clinical and Experimental·S TornelloA F De Nicola