scholarly journals Dopamine Receptor Expression and Function in Clinically Nonfunctioning Pituitary Tumors: Comparison with the Effectiveness of Cabergoline Treatment

2004 ◽  
Vol 89 (4) ◽  
pp. 1674-1683 ◽  
Author(s):  
Rosario Pivonello ◽  
Carmela Matrone ◽  
Mariagiovanna Filippella ◽  
Luigi M. Cavallo ◽  
Carolina Di Somma ◽  
...  
Keyword(s):  
Dopamine Receptor ◽  
D2 Receptor ◽  
Pituitary Tumors ◽  
Receptor Expression ◽  
Treatment Schedule ◽  
Α Subunit ◽  
Tumor Mass ◽  
Isoform Expression ◽  
And Function

Abstract The aim of this study was to correlate dopamine receptors and D2 isoform expression with the cabergoline effect on α-subunit secretion in vitro and tumor mass in vivo in clinically nonfunctioning pituitary tumors. Eighteen patients were subjected to neurosurgery, and a tumor sample was used for dopamine receptor and D2 isoform expression evaluation by RT-PCR and the in vitro functional studies. After neurosurgery, nine of 18 patients with persistent tumor were treated with cabergoline and tumor mass was evaluated before and after 1 yr treatment. D2 receptor was expressed in 67% of cases. D2long was found in 50%, D2short in 17%, and both D2 isoforms in 33% of cases. D4 receptor was also expressed in 17% of cases. The in vitro inhibition of α-subunit concentration was found in 56% of cases and was associated with D2 expression (χ2 = 5.6; P < 0.05). After 1 yr of cabergoline treatment, tumor shrinkage was evident in 56% of patients and was associated with D2 expression (χ2 = 5.6; P < 0.05). The expression of D2short rather than D2long isoform is associated with the most favorable response of the tumor to cabergoline treatment. In conclusion, this study demonstrates D2 receptor expression and function in nearly 70% of cases, suggesting a role of this drug in the treatment schedule of clinically nonfunctioning pituitary tumors.

scholarly journals Dopamine Receptor Expression and Function in Corticotroph Pituitary Tumors

2004 ◽  
Vol 89 (5) ◽  
pp. 2452-2462 ◽  
Author(s):  
Rosario Pivonello ◽  
Diego Ferone ◽  
Wouter W. de Herder ◽  
Johan M. Kros ◽  
Maria Laura Del Basso De Caro ◽  
...  
Keyword(s):  
Dopamine Receptor ◽  
Pituitary Tumors ◽  
Receptor Expression ◽  
And Function

Dopamine Receptor Expression and Function in Clinically Nonfunctioning Pituitary Tumors: Comparison With the Effectiveness of Cabergoline Treatment

2005 ◽  
Vol 60 (1) ◽  
pp. 33-34
Author(s):  
Rosario Pivonello ◽  
Carmela Matrone ◽  
Mariagiovanna Filippella ◽  
Luigi M. Cavallo ◽  
Carolina di Somma ◽  
...  
Keyword(s):  
Dopamine Receptor ◽  
Pituitary Tumors ◽  
Receptor Expression ◽  
And Function

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

scholarly journals Histamine H2 receptor radioligands: triumphs and challenges

2021 ◽  
Author(s):  
Steffen Pockes ◽  
Katharina Tropmann
Keyword(s):  
Receptor Expression ◽  
In Vitro Assays ◽  
Histamine H2 Receptor ◽  
Drug Candidates ◽  
Carbon 14 ◽  
The Central Nervous System ◽  
And Function ◽  
Role And Function

Since the discovery of the histamine H2 receptor (H2R), radioligands were among the most powerful tools to investigate its role and function. Initially, radiolabeling was used to investigate human and rodent tissues regarding their receptor expression. Later, radioligands gained increasing significance as pharmacological tools in in vitro assays. Although tritium-labeling was mainly used for this purpose, labeling with carbon-14 is preferred for metabolic studies of drug candidates. After the more-or-less successful application of numerous labeled H2R antagonists, the recent development of the G protein-biased radioligand [3H]UR-KAT479 represents another step forward to elucidate the widely unknown role of the H2R in the central nervous system through future studies.

scholarly journals Purines as Transmitter Molecules: Electrophysiological Studies on Purinergic Signalling in Different Cell Systems

2009 ◽  
Author(s):  
Elisabetta Coppi
Keyword(s):  
Cell Signalling ◽  
Human Mesenchymal Stem Cells ◽  
Membrane Receptors ◽  
Receptor Expression ◽  
Purinergic Signalling ◽  
Cell Systems ◽  
Cellular Processes ◽  
Electrophysiological Studies ◽  
And Function

Purinergic nucleotides and nucleosides (ATP, ADP, AMP and adenosine) are essential intracellular metabolites involved in a number of cellular processes, from energy supply to protein phosphorylation. However, in the last years, several studies demonstrated their involvement in cell signalling by the activation of specific membrane receptors (P1 and P2) and their role as neurotransmitters began to be investigated. The present work was aimed to clarify the effects of purinergic neurotransmission in different cell systems by using electrophysiological techniques. Relevant results of this research include the observation that P1 and P2 receptors play a deleterious role during "in vitro" ischemia in the rat brain, and the first demonstration of P2 receptor expression and function in a line of adult human mesenchymal stem cells.

Sign in / Sign up

Export Citation Format

Share Document