MODULATORY EFFECTS OF PEPTIDE GHRELIN ON URINARY BLADDER AND ITS ROLE IN DIABETES

R. E. Kalfin, M. I. Lazarova, A. N. Tolekova, P. V. Hadzibozheva

Abstract: Plasma ghrelin levels manifest “biphasic changes” in diabetes mellitus. In order to investigate ghrelin effects and mechanisms of action in diabetes, firstly we should know how this peptide modulates urinary bladder muscles under normal conditions. We found no statistically significant changes in contractile activity after application of ghrelin alone as compared to the spontaneous activity. The effects of ghrelin were displayed when it was applied in combination with other peptides. For example, 30 min after ghrelin application, the administration of Ang II did not lead to the typical tonic contractions occurring when only Ang II was administrated. The amplitude of the Ang II stimulated contractions was reduced from 1.90 ± 0.20 g to 0.78 ± 0.09 g in the presence of ghrelin (n = 21, P < 0.05). Based on these results we can assume that the urinary bladder possesses receptors for ghrelin, which are different from those in the digestive tract, with respect to the kind of intracellular
signalling mechanism to which they are coupled.

Keywords: contractile activity; diabetes; ghrelin; smooth muscle; urinary bladder

Date published: 2019-04-11