AJP - Cell Physiology, Vol 254, Issue 6 C727-C734, Copyright © 1988 by American Physiological Society
Optical absorbance changes induced by CCK-8 under limited O2 supply in isolated perfused rat pancreas
T. Matsumoto and T. Kanno
Department of Physiology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Optical absorbance spectra were recorded simultaneously and continuously in
the isolated rat pancreas arterially perfused at various flow rates. This
was done to explain how optical absorbance changes corresponding to
parallel reduction of cytochromes aa3, b, and cc1 were observed in perfused
pancreas stimulated with high concentration of an exocrine secretagogue
such as cholecystokinin-(26-33) (CCK-8). With perfusion flow rate between
1.5 and 3.0 ml/min, there were no optical absorbance changes corresponding
to cytochrome reduction, but these optical absorbance changes occurred when
the perfusion flow rate was decreased to 1.0 ml/min. These optical
absorbance changes were not observed during exocrine secretion stimulated
by CCK-8 (30 pM, 100 pM, and 1 nM) at the perfusion flow rate of 3.0
ml/min. Transient but slight changes in optical absorbances, which
correspond to reduction of cytochromes, were observed in the glands
perfused at the flow rate of 2.0 ml/min when secretion was stimulated by 1
nM CCK-8. When the perfusion flow rate was decreased to 1.0-1.5 ml/min,
these optical absorbance changes corresponding to reduction of cytochromes
occurred in glands stimulated by CCK-8 (30 pM, 100 pM, and 1 nM). Optical
absorbance changes corresponding to reduction of mitochondrial cytochromes
during secretion stimulated with CCK-8 may indicate local hypoxia in the
perfused organ.
