[Effects of different natural stimulants on the activity of the rabbits' carotid chemoreceptor].
The effects of different natural stimulants on the afferent unit discharge of rabbit carotid chemoreceptors were studied in the in vitro carotid body- sinus nerve preparation. A total of 32 chemoreceptive units were recorded. The results were as follows: (1) Of the 32 units, 10 (31%) showed chemosensory responses only to PO2 decrease; 9 (28%) to all stimulants (PO2 decrease, PCO2 increase and pH decrease); 9 (28%) to PO2 decrease and PCO2 increase; 3 (9%) to PO2 decrease and pH decrease; only one to pH decrease. (2) The potency of the three natural stimulants in eliciting the changes in intensity of discharge showed a decreasing order as follows: PO2 decrease > PCO2 increase > pH decrease. The above results suggest that the carotid body may contain only one or a combination of 2 or 3 kinds of chemoreceptors respectively sensitive to decrease PO2 to increase PCO2 or decrease pH.
Pang
L
L
Department of Physiology, Hebei Academy of Medical Sciences, Shijiazhuang.
Miao
Z H
ZH
Wang
Y L
YL
Dong
L
L
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood; D002344:Carotid Body / Q000502:physiology*; D002346:Carotid Sinus / Q000502:physiology*; D002628:Chemoreceptor Cells / Q000502:physiology*; D004594:Electrophysiology; D005260:Female; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D010100:Oxygen / Q000097:blood; D011817:Rabbits
D002245:Carbon Dioxide; D010100:Oxygen