Variation in the Proportions of Individual Pepsins Secreted by the Cat in Response to Vagal Stimulation and Hypoglycaemia

1. Gastric juice was collected at regular intervals during electrical stimulation of the vagus in anaesthetized cats and during insulin hypoglycaemia in both anaesthetized and conscious cats. The total amounts of acid and pepsin secreted were similar in the three groups. 2. Pepsins were examined by agar-gel electrophoresis. Resting juice contained two pepsins, and up to nine pepsins could be detected after stimulation. Three patterns of pepsin secretion were found. 3. The most noticeable feature was the variation in the proportion of total pepsin attributable to the pepsin which migrated most rapidly during electrophoresis (pepsin 1). In response to insulin hypoglycaemia, anaesthetized cats secreted only a small proportion of total pepsin as pepsin 1 and conscious cats secreted a large proportion as pepsin 1. During direct electrical stimulation of the vagus, the proportion of pepsin 1 rose. 4. The possibility of a dependence of pepsin 1 secretion on vagal stimulation is discussed and the relevance of this to peptic ulcer and to vagotomy is considered.

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Cerebral-evoked potential responses following direct vagal and esophageal electrical stimulation in humans

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1993.264.3.g486 ◽

1993 ◽

Vol 264 (3) ◽

pp. G486-G491 ◽

Cited By ~ 10

Author(s):

G. Tougas ◽

P. Hudoba ◽

D. Fitzpatrick ◽

R. H. Hunt ◽

A. R. Upton

Keyword(s):

Electrical Stimulation ◽

Evoked Potential ◽

Vagal Stimulation ◽

Direct Electrical Stimulation ◽

Sensory Pathways ◽

Afferent Fibers ◽

Health And Disease ◽

Esophageal Sphincter ◽

Afferent Response ◽

Stimulation Of

Cerebral evoked responses following direct electrical stimulation of the vagus and esophagus were compared in 8 epileptic subjects and with those recorded after esophageal stimulation in 12 healthy nonepileptic controls. Direct vagal stimulation was performed using a left cervical vagal pacemaker, which is used in the treatment of epilepsy. Esophageal stimulation was obtained with the use of an esophageal assembly incorporating two electrodes positioned 5 and 20 cm orad to the lower esophageal sphincter. Evoked potential responses were recorded with the use of 20 scalp electrodes. The evoked potential responses consisted of three distinct negative peaks and were similar with the use of either vagal or esophageal stimulation. The measured conduction velocity of the afferent response was 7.5 m/s in epileptic subjects and 10 m/s in healthy controls, suggesting that afferent conduction is through A delta-fibers rather than slower C afferent fibers. We conclude that the cortical-evoked potential responses following esophageal electrical stimulation are comparable to direct electrical stimulation of the vagus nerve and involve mostly A delta-fibers. This approach provides a method for the assessment of vagal afferent gastrointestinal sensory pathways in health and disease.

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