Effects of Growth Hormone Releasing Peptides on Stimulated Growth Hormone Secretion in Old Rats

1994 ◽  
pp. 167-192 ◽  
Author(s):  
Richard F. Walker ◽  
Sei-Won Yang ◽  
Ryuji Masuda ◽  
Cheng-Shih Hu ◽  
Barry B. Bercu
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Old Rats ◽  
Growth Hormone Releasing Peptides

scholarly journals Synthetic Growth Hormone-Releasing Peptides (GHRPs): A Historical Appraisal of the Evidences Supporting Their Cytoprotective Effects

2017 ◽  
Vol 11 ◽  
pp. 117954681769455 ◽  
Author(s):  
Jorge Berlanga-Acosta ◽  
Angel Abreu-Cruz ◽  
Diana García-del Barco Herrera ◽  
Yssel Mendoza-Marí ◽  
Arielis Rodríguez-Ulloa ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Biological Effects ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Antioxidant Defenses ◽  
Original Research ◽  
English Only ◽  
Hepatic Cells ◽  
Growth Hormone Releasing Peptides ◽  
Search Design

Background: Growth hormone-releasing peptides (GHRPs) constitute a group of small synthetic peptides that stimulate the growth hormone secretion and the downstream axis activity. Mounting evidences since the early 1980s delineated unexpected pharmacological cardioprotective and cytoprotective properties for the GHRPs. However, despite intense basic pharmacological research, alternatives to prevent cell and tissue demise before lethal insults have remained as an empty niche in the clinical armamentarium. Here, we have rigorously reviewed the investigational development of GHRPs and their clinical niching perspectives. Methodology: PubMed/MEDLINE databases, including original research and review articles, were explored. The search design was date escalated from 1980 and included articles in English only. Results and Conclusions: GHRPs bind to two different receptors (GHS-R1a and CD36), which redundantly or independently exert relevant biological effects. GHRPs’ binding to CD36 activates prosurvival pathways such as PI-3K/AKT1, thus reducing cellular death. Furthermore, GHRPs decrease reactive oxygen species (ROS) spillover, enhance the antioxidant defenses, and reduce inflammation. These cytoprotective abilities have been revealed in cardiac, neuronal, gastrointestinal, and hepatic cells, representing a comprehensive spectrum of protection of parenchymal organs. Antifibrotic effects have been attributed to some of the GHRPs by counteracting fibrogenic cytokines. In addition, GHRP family members have shown a potent myotropic effect by promoting anabolia and inhibiting catabolia. Finally, GHRPs exhibit a broad safety profile in preclinical and clinical settings. Despite these fragmented lines incite to envision multiple pharmacological uses for GHRPs, especially as a myocardial reperfusion damage-attenuating candidate, this family of “drugable” peptides awaits for a definitive clinical niche.

PLASMA LEVELS OF GROWTH HORMONE IN FEMALE RATS OF DIFFERENT AGES

1978 ◽  
Vol 88 (4) ◽  
pp. 676-690 ◽  
Author(s):  
Staffan Edén ◽  
Kerstin Albertsson-Wikland ◽  
Olle Isaksson
Keyword(s):  
Growth Hormone ◽  
Sequential Sampling ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Female Rats ◽  
Fasting Period ◽  
Age Related ◽  
Different Ages ◽  
Old Rats ◽  
Plasma Gh

ABSTRACT Radioimmunoassayable growth hormone (GH) was determined in fed and fasted female rats of different ages. In 6–40 day-old rats blood was collected at hourly intervals in groups of rats at different time intervals during the day. Within each age group the variation in plasma GH was considerable. In 6–14 day-old rats plasma GH was generally elevated. By day 18 levels declined, lowest on day 22 and by day 26 again increasing. In 14 day-old rats the median plasma level of GH was 22 ng/ml, in 22 day-old rats < 5 ng/ml and in 40 day-old rats 43 ng/ml. In 14 day-old rats levels ranged from < 5 ng/ml – 148 ng/ml, in 22 day-old rats from < 5 ng/ml – 34 ng/ml and in 40 day-old rats from < 5 ng/ml – > 200 ng/ml. A 20 h fasting period was associated with a significant decrease in plasma GH. In 45 day-old rats, the variations in plasma GH of individual animals were studied by obtaining sequential blood samples from unrestrained, undisturbed animals with implanted intra-aortic cannulae. In these rats GH secretion was characterized by an episodic release, occurring every 2–4 h. After a 20 h fasting period major peaks were depressed and occurred less frequently. It is concluded that there is an age-related as well as a circadian rhythm in growth hormone secretion in the rat and that sequential sampling of blood is essential for the evaluation of the secretory pattern.

THE EFFECT OF BETA-RECEPTOR BLOCKADE ON EXERCISE AND ARGININE-INDUCED GROWTH HORMONE SECRETION IN MAN

1974 ◽  
Vol 77 (1_Suppl) ◽  
pp. S6 ◽  
Author(s):  
S. Raptis ◽  
H. Hirth-Schmidt ◽  
K. E. Schröder ◽  
E. F. Pfeiffer
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Receptor Blockade ◽  
Beta Receptor ◽  
Beta Receptor Blockade

Growth hormone secretion in children treated for medulloblastoma

2018 ◽  
Author(s):  
Alexey Kalinin ◽  
Natalia Strebkova ◽  
Olga Zheludkova ◽  
Maria Kareva
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion

scholarly journals Spontaneous oscillations of intracellular calcium and growth hormone secretion.

1988 ◽  
Vol 263 (20) ◽  
pp. 9682-9685
Author(s):  
R W Holl ◽  
M O Thorner ◽  
G L Mandell ◽  
J A Sullivan ◽  
Y N Sinha ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Intracellular Calcium ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Spontaneous Oscillations
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