AJP - Renal Physiology, Vol 252, Issue 4 761-F767, Copyright © 1987 by American Physiological Society
Surgical thyroparathyroidectomy of the rabbit
S. Q. Tan, D. Thomas, W. Jao, J. E. Bourdeau and K. Lau
Previous studies in the rabbit suggest resistance to parathyroid hormone
(PTH) despite the reported presence of PTH-sensitive adenylate cyclase
activity in renal cortical slices and tubules. The lack of response may
reflect difficulties with complete parathyroidectomy in this species, which
has been reported to possess 32 accessory glands. Aided by systematic
histology of tissues extirpated during exploration, we tested the
hypothesis that the rabbit possesses only four functional parathyroid
glands and that the rabbit kidney is sensitive to the expected
physiological actions of endogenous PTH. In all rabbits studied, only four
glands could be identified histologically, two within the thyroids and two
located in the fascial plane between the sternohyoid and sternothyroid
muscles and the carotid artery. Surgical thyroparathyroidectomy markedly
reduced serum Ca (6.3 vs. 10.6 mg/dl in sham-operated controls), increased
the clearance (C) (3.51 vs. 0.78 ml/min) and fractional excretion (FE) of
Ca (44.5 vs. 8.3%) while decreasing CP (1.14 vs. 2.40 ml/min), FEP (14.8
vs. 29.9%) and adenosine 3',5'-cyclic monophosphate (cAMP) excretion (341
vs. 760 pmol/min). These findings demonstrate the feasibility of using the
described techniques for complete parathyroidectomy in the rabbit.
Furthermore, they document the presence of only four functioning
parathyroid glands and the renal sensitivity to endogenous PTH in this
species.
