Submitted on April 12, 2007
Accepted on December 14, 2007
Sustained hypoxia-induced proliferation of carotid body type I cells in rats
Zun-Yi Wang1*, E. Burt Olson2, Dale Edmond Bjorling3, Gordon S. Mitchell4, and Gerald E. Bisgard4
1 Surgical Sciences, University of Wiscosin-Madison, Madison, Wisconsin, United States
2 Preventive Medicine, University Wisconsin-Madison, Madison, Wisconsin, United States
3 Surgical Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
4 Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
* To whom correspondence should be addressed. E-mail: wangz{at}svm.vetmed.wisc.edu.
Sustained hypoxia (SH) has been shown to cause profound morphological and cellular changes in carotid body (CB). However, results regarding whether SH causes CB type I cell proliferation are conflicting. By using bromodeoxyuridine (BrdU), a uridine analog that is stably incorporated into cells undergoing DNA synthesis, we have found that SH causes the type I cell proliferation in the CB; the proliferation occurs mainly during the first 1-3 days of hypoxic exposure. Moreover the new cells survive for at least one month after the return to normoxia. Also, SH does not cause any cell death in CB as examined by the TUNEL assay. Taken together, our results suggest that SH stimulates CB type I cell proliferation which may produce long-lasting changes in CB morphology and function.
