Possible Interaction: Melatonin and Somatostatin

“In human islets in batch culture of a nondiabetic donor, an increase of somatostatin secretion was observed under melatonin treatment while in islets of a type 2 diabetic donor, an inhibitory influence could be observed, especially in the presence of 5.5 mmol/L glucose.”

“Analysis of a human pancreatic δ‐cell model, the cell line QGP‐1, and the use of a somatostatin‐specific radioimmunoassay showed that melatonin primarily has an inhibitory effect on somatostatin secretion in the physiological concentration range.”

“In the pharmacological range, melatonin elicited slightly increased somatostatin release from δ‐cells.”

“ Somatostatin release from the δ‐cells at low glucose concentrations was significantly inhibited during co‐incubation with 1 nm melatonin , an effect which was less pronounced at higher glucose levels.”

“These data point to a significant influence of melatonin on pancreatic δ‐cells and on somatostatin release.”

“Taken together our results indicate that co-administration of melatonin with all-trans retinoic acid and somatostatin may be of significant therapeutic benefit in breast cancer.”

“ MEL , via Mel1b and Mel1c, decreased SST secretion under GL, which was associated with the inhibition of SST, SSTR2, and SSTR5 in adenohypophysis cells.”

“ MT increased GH and prolactin (PRL) expression/release in a dose- and time-dependent fashion, a response that was blocked by somatostatin.”

“It is suspected that this mechanism is triggered by an increase in somatostatin synthesis with inhibition of growth hormone, thyroid-stimulating hormone, and melatonin , and with a loss of circadian function in the suprachiasmatic nuclei of the hypothalamus.”

“ Melatonin administration for 4 days induced a decrease in the hippocampal somatostatin (SRIF)-like immunoreactivity content as well as a decrease in the number of SRIF receptors and an increase in their apparent affinity.”

“We have previously demonstrated that acute melatonin treatment regulates the somatostatinergic system in the rat hippocampus.”

“As SRIF exerts an opposite effect to that of melatonin on hippocampal neuronal activity, it is possible that the SRIFergic system could be implicated in the mechanism of action of melatonin in the rat.”

“Four days of melatonin administration induced both an increase in the number of [125I]‐Tyr11‐somatostatin receptors and a decrease in the affinity of somatostatin for its receptors in frontoparietal cortical membranes.”

“The capacity of SRIF to inhibit basal and forskolin (FK)‐stimulated adenylyl cyclase (AC) activity was increased in melatonin‐treated rats as compared to the control animals.”