Daily rhythms in endocrine factors of the somatotropic axis and their receptors in gilthead sea bream (Sparus aurata) larvae
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY
Authors: Galal-Khallaf, Asmaa; Mohammed-Geba, Khaled; Yufera, Manuel; Martinez-Rodriguez, Gonzalo; Miguel Mancera, Juan; Lopez-Olmeda, Jose F.
Abstract
Living organisms have adapted to environmental oscillations in light and temperature through evolving biological clocks. Biological rhythms are pervasive at all levels of the endocrine system, including the somatotropic (growth) axis. The objective of the present research was to study the existence of daily rhythms on the somatotropic axis of a marine teleost species, specifically, the gilthead sea bream (Sparus aurata). Larvae of S. aurata at 30 dph (days post hatching), kept under a 9 L:15D (light-dark) photoperiod, were collected every 3 h throughout a 36 h cycle. The expression of the following somatotropic axis genes was analyzed by quantitative PCR: pituitary adenylate cyclase-activating polypeptide 1 (adcyap1), prepro-somatostatin-1 (pss1), growth hormone (gh), growth hormone receptor types 1 and 2 (ghr1 and ghr2, respectively), insulin-like growth factor 1 (igf1) and igf1 receptor a (igf1ra). All genes displayed significant differences among time points and, with the exception of adcyap1, all showed statistically significant daily rhythms. The acrophases of gh, ghr1, ghr2, igf1 and igf1ra were located around the end of the dark phase, between ZT19:44 and ZT0:48 h, whereas the highest expression levels of adcyap1 occurred at ZT18 h. On the other hand, the acrophase of pss1, an inhibitor of Gh secretion, was located at ZT10:16 h, hence it was shifted by several hours with respect to the other genes. The present results provide the first thorough description of somatotropic axis rhythms in gilthead sea bream. Such knowledge provides insights into the role of rhythmic regulation of the Gh/Igf1 axis system in larval growth and metabolism, and it can also improve the implementation of more species-specific feeding regimes.
The effect of somatostatin analogs and acromegaly on the upper gastrointestinal system
PITUITARY
Authors: Sahin, Serdar; Icli, Tevhide Betul; Durcan, Emre; Sulu, Cem; Ozkaya, Hande Mefkure; Hatemi, Ali Ibrahim; Kadioglu, Pinar
Abstract
Purpose To evaluate the effects of somatostatin analogs and disease activity status on the upper gastrointestinal system in patients with acromegaly. Methods One hundred eighty-one patients with acromegaly were retrospectively assessed. The demographic, biochemical, pathologic, and radiologic data of the patients were evaluated. The upper gastrointestinal endoscopies and endoscopic biopsies were investigated. We divided patients into four groups according to the use of somatostatin analogs, and into two groups according to disease activity. We compared the data of patients between groups A, B, C, and D, and controlled/uncontrolled groups separately. Results Before and in the peri-endoscopic period, 67 and 27 patients were being treated with octreotide long-acting release (LAR) (group A) and lanreotide autogel (group B), respectively. Twenty-one patients used somatostatin analogs, but they were stopped for various reasons before upper gastrointestinal endoscopy (group C), and 66 patients did not use a somatostatin analog (group D). In the peri-endoscopic period, 103 (60%) patients were responsive to medical and/or surgical treatment and 67 (40%) patients were non-responsive. The rate of gastritis was higher in group A than in groups B and D. The incidence of duodenitis and gastric ulcer was much higher in group D. The rate of gastritis was higher in the controlled group compared to the uncontrolled group. Conclusion The study showed that octreotide LAR treatment could be a risk factor in addition to known factors for the development of gastritis in patients with acromegaly.