Abstract
To assess nutrient sensitivity in a population of gastric load-sensitive vagal afferents, their neurophysiological activity was examined in anesthetized rats with inflated pyloric cuffs after gastric infusion of a range of volumes of nutrient and equiosmotic saline solutions. Responses to physiological saline loads (1, 2, 4, and 8 ml) were compared with responses elicited by the same volume range of carbohydrate (12.5% glucose), protein (12.5% peptone), and equiosmotic hypertonic (750 mosM) saline. The threshold load volume of physiological saline required to increase gastric vagal afferent activity was 1 ml. Thereafter, there was a dose-dependent relationship between increasing gastric volume and firing rate and between gastric volume and pressure. The dose-response relationships elicited by glucose, peptone, and equiosmotic hypertonic saline loads did not differ from those elicited by physiological saline loads. These data identify a population of gastric load-sensitive vagal afferents unresponsive to the chemical composition of gastric contents and are consistent with a role for vagal gastric volume signals but not gastric nutrient content in the negative feedback control of ingestion.
| Original language | English (US) |
|---|---|
| Pages (from-to) | R280-R286 |
| Journal | American Journal of Physiology - Regulatory Integrative and Comparative Physiology |
| Volume | 274 |
| Issue number | 2 43-2 |
| State | Published - Feb 1 1998 |
| Externally published | Yes |
Keywords
- Brain-gut communication
- Food intake
- Vagus
- Visceral afferents
ASJC Scopus subject areas
- Physiology
- Physiology (medical)