Irving, J. T.

Solms, C. M.

English

Wits Institutional Repository on DSPACE

32 The South African Journal o f Medical Sciences
The Influence of Parathyroid Hormone upon Bone Formation in Xenopus 
Lae vis, by J. T. Irving and C. M. Sol ms {Joint Dental Research Unit o f the 
Council for Scientific and Industrial Research and the University o f the Witwaters- 
rand, Johannesburg; and the Department o f Physiology, Medical School, Uni­
versity o f Cape Town).
This communication and the next report work which is a continuation of that 
previously published [Fox and Irving, 1950a, b].
Forty-nine female Xenopus weighing approximately 60 g. were used. They were 
injected once intrapcritoneally with “Lilly” parathormone in doses of 1/10, 1/5, 
1/2, 2 or 3 units in equal volumes of solution, and were killed 3 hours to 12 days 
subsequently. Control animals were injected with the same volume of saline. Blood 
was taken for Ca estimations and the femora were removed, decalcified and stained 
after longitudinal section with liacmatoxylin and cosin.
The blood Ca levels did not change significantly throughout the whole of the 
experiment compared with those of the controls. An osteoclast response was observed 
in several bones in the parts of the femoral shaft normally undergoing resorption. 
This response occurred with one exception from 6 to 48 hours after injection at all 
dose levels, and while evident, was not nearly so pronounced as has been reported 
in mammals. The osteoclasts were large multi nucleated cells, situated against the 
bone face and usually in Howship’s lacunae, and often containing orange staining 
material.
Both Jordan [1925] using Rana pipiens, and Fox and Irving [1950a] working 
with Xenopus, found either no osteoclasts or excessively few in the bones of adult 
animals. Schlumberger and Burk [1953] injected 100,000 or more i.u. of vitamin D 
into Xenopus and observed osteoporosis and Howship’s lacunae with osteoclasts 
in the femora. They also gave 10 units of parathyroid extract to Rana pipiens and 
obtained an occasional small focus of osteoclastic activity, it would thus appear 
that amphibia arc not very sensitive to mammalian parathyroid extract, and it may 
well be that amphibian parathyroid hormone differs chemically from that of mam­
mals. Amphibia arc, however, able to form osteoclasts, an excessively rare cell in 
adults, if the stimulus is sufficiently great. In the present experiments the para­
thormone was tested on rats and found to be active in raising the blood Ca level.
REFERENCES
Fox, E. and Irving, J. T. (i950a) S. AJr. J. /tied. Sci., 15, 5.
Fox, E. and Irving, J. T. (1950b). 5. Afr. J. med. Sci.. 15, 1 J.
Jordan, H. E. (1925). A m t. Rec., 30, 107.
Schlumberger, H. G. and B urk, D . H. (1953). Arch. Rath.y 56, 103.
Till Influence or Oestrogen Upon Bone Formation I n  Xenopus Lae vis, by 
J. T. Irving and C. M. Solms {Joint Dental Research Unit o f the Council for 
Scientific and Industrial Research and the University o f the Witwatersrand, Johan­
nesburg; and the Department o f Physiologyy Medical School, University o f Cape 
Town).
Oestrogen is well known to cause medullary bone formation in birds [Bloom et al., 
1941 ] and mice [Gardner and Pfeiffer, 1938]. Pfeiffer [1951] at a conference on bone 
formation enquired if this action of oestrogen had been tested on Xenopus, and as 
far as is known this has not been done.
Two groups of Xenopus were chosen, young frogs taken, two to four days aftei 
metamorphosis, and adult female frogs about 60 g. in weight The young frogs


The influence of parathyroid hormone upon bone formation in xenopus laevis

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The influence of parathyroid hormone upon bone formation in xenopus laevis

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