Gastric secretion elicited by conditioning in rats.
OBJECTIVE
To investigate whether interdigestive gastric acid secretion can be controlled by a possible memory-related cortical mechanism.


METHODS
To evaluate gastric secretion in rats, we used a methodology that allows gastric juice collection in rats in their habitual conditions (without any restraining) by pairing sound as the conditioning stimulus (CS) and food as the unconditioning stimulus (US). The levels of gastric acid secretion under basal conditions and under sound stimulation were recorded and the circulating gastrin levels determined.


RESULTS
When the gastric juice was collected in the course of the conditioning procedure, the results showed that under noise stimulation a significant increase in gastric acid secretion occurred after 10 days of conditioning (p<0.01). The significance was definitively demonstrated after 13 days of conditioning (p<0.001). Basal secretions of the conditioned rats reached a significant level after 16 days of conditioning. The levels of noise-stimulated gastric acid secretion were the highest so far described in physiological experiments carried out in rats and there were no significant increases in the circulating gastrin levels.


CONCLUSIONS
The results point to the important role played by cortical structures in the control of interdigestive gastric acid secretion in rats. If this mechanism is also present in humans, it may be involved in diseases caused by inappropriate gastric acid secretion during the interprandial periods.
Caboclo
José Liberato Ferreira
JL
Department of Surgery, Medical School of Sao Jose do Rio Preto (FAMERP), SP, Brazil. liberatocaboclo@gmail.com
Cury
Francico de Assis
Fde A
Borin
Aldenis Albanese
AA
Caboclo
Luís Otávio Sales Ferreira
LO
Ribeiro
Maria Fernanda Sales Caboclo
MF
de Freitas
Pedro José
PJ
Andersson
Sven
S