masterThesis
Avaliação da contração da musculatura lisa do trato gastrointestinal e geniturinário em um modelo animal de depressão
Fecha
2021-08-20Registro en:
GOMES, Luana Talinne da Costa. Avaliação da contração da musculatura lisa do trato gastrointestinal e geniturinário em um modelo animal de depressão. 2021. 66f. Dissertação (Mestrado em Ciências Biológicas) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2021.
Autor
Gomes, Luana Talinne da Costa
Resumen
Several reports have demonstrated that depressive disorder is strongly related to
somatic symptoms mainly characterized by gastrointestinal (constipation, delayed
gastric emptying etc) or genitourinary (incontinence, overactive bladder, delayed
ejaculation, poor sperm quality etc) alterations. The pathophysiological mechanisms
behind the relationship between depressive disorder and somatic symptoms are still
not fully understood. Therefore, this study aimed to evaluate the motor activity of
gastrointestinal (fundus of stomach and duodenum) and genitourinary tract (bladder).
Adult male mice were submitted to learned helplessness model (being classified as
helpless and resilient) or controllable stress. After that, animals were euthanized and
the fundus of stomach, duodenum or bladder isolated and mounted in a standard organ
bath preparation. We evaluated the contractile effects induced by KCl 80 mM for 5 min
or carbachol (muscarinic agonists; 10-7 – 10-3M). The relaxant effect of isoproterenol
(β adrenoceptor agonist; 10-10 – 10-4M) was checked. Animals from different
experimental group were also used for analyzing of gastric emptying and intestinal
transit. We found an increase of the KCl induced contractions by about 120% in bladder
from resilient animals. The maximum effect of carbachol was augmented (~95%) in
bladder from helpless and resilient animals when compared to control. We also found
that the potency of carbachol was 3-fold higher in bladder from resilient mice compared
to control. The relaxing induced effects of isoproterenol were decreased by 30% in
bladder from both helpless and resilient mice. The maximum effect of carbachol was
increased by 50% and 30% in fundus of stomach from helpless and resilient mice,
respectively. On the other hand, the maximum relaxing effects promoted by
isoproterenol were reduced by 20% in fundus of stomach from resilient mice when
compared to control. Duodenum contractions induced by KCl or carbachol were not
altered in helpless or resilient mice although the maximum effect of isoproterenol was
diminished by 30% in resilient mice. The controllable stress did not alter the response
of bladder, fundus of stomach or duodenum to KCl, carbachol or isoproterenol. Further,
animals submitted to learned helplessness or controllable stress did not exhibited
alterations in gastric emptying or intestinal transit. In conclusion, incontrollable stress
and not depressive phenotype (helpless animals) or controllable stress could be
related to the alterations in motor activity of bladder and fundus of stomach. More
studies are needed to identify the molecular mechanism by which stress might affect
the motor activity of gastrointestinal or genitourinary tract.