Abstract
Intraluminal pressures and myoelectric activity were recorded from the feline antrum, pylorus, and duodenum in response to intraduodenal amino acid solutions. Mixed amino acids (0.02 mg/ml, 3.0 ml) increased the amplitude of pyloric contractions (59.7 ± 7.9 mmHg) and pyloric spike activity (73.7 ± 6.8% of slow waves with spike activity) compared with a saline control (P < 0.001). The selectivity of these responses was determined with specific amino acids. L-Tryptophan (10 or 40 mM) produced a response similar to the mixed amino acid response, while L-phenylalanine or L-glycine (10 or 40 mM) had no effect. Intra-arterial tetrodotoxin, intraluminal ethyl aminobenzoate, or intravenous naloxone (1.0 mg/kg) abolished the pyloric responses to amino acids (P < 0.02). Bilateral cervical vagotomy had no effect. Cholecystokinin octapeptide (CCK-OP) produced dose-dependent increases in the amplitude of pyloric contractions and in pyloric spike activity. The ED50 dose of CCK-OP (1.0 μg/kg iv) gave an increase in pyloric pressure of 155.6 ± 49.9 mmHg and in spike activity of 77.7 ± 9.4%, similar to mixed amino acids or tryptophan. These effects of CCK-OP were not antagonized, however, by a dose of naloxone (1.0 mg/kg) that blocked the maximal pyloric response to leucine-enkephalin. We concluded 1) intraduodenal mixed amino acids or tryptophan increase phasic, spike-dependent pyloric contractions in the cat via nonvagal, naloxone-sensitive neural pathways, 2) phenylalanine, a structurally similar essential amino acid, had no effect on the feline gastroduodenal junction, and 3) the pyloric responses to exogenous CCK-OP are mediated by pathways distinct from the responses to tryptophan or mixed amino acids.
| Original language | English (US) |
|---|---|
| Pages (from-to) | G307-G312 |
| Journal | American Journal of Physiology - Gastrointestinal and Liver Physiology |
| Volume | 11 |
| Issue number | 3 |
| State | Published - Jan 1 1985 |
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All Science Journal Classification (ASJC) codes
- Physiology
- Hepatology
- Gastroenterology
- Physiology (medical)
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Opiate nerves mediate feline pyloric response to intraduodenal amino acids. / Reynolds, J. C.; Ouyang, A.; Cohen, S.
In: American Journal of Physiology - Gastrointestinal and Liver Physiology, Vol. 11, No. 3, 01.01.1985, p. G307-G312.Research output: Contribution to journal › Article
TY - JOUR
T1 - Opiate nerves mediate feline pyloric response to intraduodenal amino acids
AU - Reynolds, J. C.
AU - Ouyang, A.
AU - Cohen, S.
PY - 1985/1/1
Y1 - 1985/1/1
N2 - Intraluminal pressures and myoelectric activity were recorded from the feline antrum, pylorus, and duodenum in response to intraduodenal amino acid solutions. Mixed amino acids (0.02 mg/ml, 3.0 ml) increased the amplitude of pyloric contractions (59.7 ± 7.9 mmHg) and pyloric spike activity (73.7 ± 6.8% of slow waves with spike activity) compared with a saline control (P < 0.001). The selectivity of these responses was determined with specific amino acids. L-Tryptophan (10 or 40 mM) produced a response similar to the mixed amino acid response, while L-phenylalanine or L-glycine (10 or 40 mM) had no effect. Intra-arterial tetrodotoxin, intraluminal ethyl aminobenzoate, or intravenous naloxone (1.0 mg/kg) abolished the pyloric responses to amino acids (P < 0.02). Bilateral cervical vagotomy had no effect. Cholecystokinin octapeptide (CCK-OP) produced dose-dependent increases in the amplitude of pyloric contractions and in pyloric spike activity. The ED50 dose of CCK-OP (1.0 μg/kg iv) gave an increase in pyloric pressure of 155.6 ± 49.9 mmHg and in spike activity of 77.7 ± 9.4%, similar to mixed amino acids or tryptophan. These effects of CCK-OP were not antagonized, however, by a dose of naloxone (1.0 mg/kg) that blocked the maximal pyloric response to leucine-enkephalin. We concluded 1) intraduodenal mixed amino acids or tryptophan increase phasic, spike-dependent pyloric contractions in the cat via nonvagal, naloxone-sensitive neural pathways, 2) phenylalanine, a structurally similar essential amino acid, had no effect on the feline gastroduodenal junction, and 3) the pyloric responses to exogenous CCK-OP are mediated by pathways distinct from the responses to tryptophan or mixed amino acids.
AB - Intraluminal pressures and myoelectric activity were recorded from the feline antrum, pylorus, and duodenum in response to intraduodenal amino acid solutions. Mixed amino acids (0.02 mg/ml, 3.0 ml) increased the amplitude of pyloric contractions (59.7 ± 7.9 mmHg) and pyloric spike activity (73.7 ± 6.8% of slow waves with spike activity) compared with a saline control (P < 0.001). The selectivity of these responses was determined with specific amino acids. L-Tryptophan (10 or 40 mM) produced a response similar to the mixed amino acid response, while L-phenylalanine or L-glycine (10 or 40 mM) had no effect. Intra-arterial tetrodotoxin, intraluminal ethyl aminobenzoate, or intravenous naloxone (1.0 mg/kg) abolished the pyloric responses to amino acids (P < 0.02). Bilateral cervical vagotomy had no effect. Cholecystokinin octapeptide (CCK-OP) produced dose-dependent increases in the amplitude of pyloric contractions and in pyloric spike activity. The ED50 dose of CCK-OP (1.0 μg/kg iv) gave an increase in pyloric pressure of 155.6 ± 49.9 mmHg and in spike activity of 77.7 ± 9.4%, similar to mixed amino acids or tryptophan. These effects of CCK-OP were not antagonized, however, by a dose of naloxone (1.0 mg/kg) that blocked the maximal pyloric response to leucine-enkephalin. We concluded 1) intraduodenal mixed amino acids or tryptophan increase phasic, spike-dependent pyloric contractions in the cat via nonvagal, naloxone-sensitive neural pathways, 2) phenylalanine, a structurally similar essential amino acid, had no effect on the feline gastroduodenal junction, and 3) the pyloric responses to exogenous CCK-OP are mediated by pathways distinct from the responses to tryptophan or mixed amino acids.
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M3 - Article
C2 - 3976889
AN - SCOPUS:0022031585
VL - 11
SP - G307-G312
JO - American Journal of Physiology
JF - American Journal of Physiology
SN - 0193-1849
IS - 3
ER -