The effects of alterations in internal Ca levels on cat small intestinal slow waves

Control of slow wave frequency in cat small intestinal muscle was investigated with microelectrodes. Exposure of intact muscle or isolated longitudinal muscle to low Ca('2+) saline decreased slow wave frequency with less than a 6 mV change in resting potential. This frequency decline was characterized by a prolongation of the diastolic phase of the slow wave. Raising Ca(,0)('2+) to 2-3 times normal increased slow wave frequency. At Ca(,0)('2+) greater than 4 times normal, the slow wave frequency again decreased. However, this decrease in frequency was characterized by a prolongation of the systolic phase of the waveform. Application of Ca conductance blockers (Co('2+), Mn('2+), D600, verapamil), increasing Mg(,0)('2+) or increasing internal pH decreased slow wave frequency by a prolongation of the diastolic region of the slow wave. Addition of db-cAMP to Krebs saline made hypertonic with sucrose or decreasing internal pH increased slow wave frequency. These results indicate a relationship between internal Ca('2+) and the pacemaker of slow wave frequency. A scheme is proposed to explain that relationship.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physiology

Year dc:date

2011

Author dc:creator

• Mangel, Allen W.

Contributors dc:contributor

• Prosser, C. Ladd
• Curtis, Brian A.
• Connor, John A.
• Arntzen, Charles J.
• Sherwood, O. David

• Physiology
• Cats
• Animals

Statement dc:rights

• Copyright 1980 Allen Wayne Mangel

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/18820

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/18820