鶏胎仔の蛋白同化ステロイド負荷に依る大腿骨の成長について

抄録

In orthopedic surgery, particularly in osteopathic situations including atrophy of the bone and osteoporosis as well as for the promotion of knitting and postoperative growth of the bone, there exists an increasing tendency toward the use of anabolic steroids which promote potassium, phosphorus and calcium retentions and has recently been shown to give an impetus toward increase in collagen content in the connective tissue and retention of acid mucopolysaccharides by the bone matrix. However, because of the undesirable androgenic effects, synthetic steroids which retain the anabolic activity of testosterone and at the same time virtually free of its androgenic effects are generally prescribed in the aformentioned clinical situations.
Massive doses of a anabolic steroid have been described to eventually affect the epiphyseal cartilage alone in causing depression of its growth in young laboratory animals, whereas by other investigators, the growth-suppressive effects of the steroid both on epiphyseal cartilage and on diaphyses have been reported to be in evidence. The present study represents an attempt to clarify the influence of overdosage of a protein anabolic steroid on the skeletal growth in the young using chick embryos.
Materials and Methods: Fertile White Leghorn eggs ranging in weight from 45 to 60 gm obtained from an imbred colony were incubated with their surface maintained at a constant temperature of 103°F and with a relative humidity between 60 and 70 per cent. Overturned twice daily, the embryonated eggs were given injections of solutions of a anabolic steroid at concentrations as to permit administration of 0, 25 and 2, 500 mcg of the compound per embryo respectively at seven days after initation of the incubation. Two additional groups of embryonated eggs received distilled water and none respectively on the same day to serve as controls. Thirteen-, sixteen- and nineteen-day-old embryos and two-day-old chicks from all these groups of eggs euthanatized with diethyl ether, on which the following examinations were performed: determination of body weight, gross pathologic examination, soft ray radiography, osteometric determination of the right femur, and microscopic examination of hematoxyline-eosine-stained or silver ni-trate-treated preparations of the whole thighbone.
Results: Both lenghts of long axis of the femur and body weight in embryos in the dosage group were practically comparable to those observed with the control, whereas with the embryos given high doses of the steroid, significant depression of gain in respect of these two parameters was evident. In 16-day-old embryos of the control and low dosage groups it was prominent that there were formation of trabeculae and a concomitant evidence of trabecular consolidation and compactness with resultant enlargement of intramedullary space. Greater distinction of the epiphyseal chondrocyte layers was also demonstrable with these groups of embryos. In contrast, there existed a tendency for the rate of trabecular and chondroepiphyseal formation as well as that of expansion of the cavum medullare to be undoubtedly depressed, and it was not until 19 to 23 day of age that overt formation of trabecular consolidation and compactness and expansion of the cavity became in evidence and not until the 23rd day following onset of the incubation that capital cartilaginous demarcation became clearly observed The data stressing close rations between findings for the capital cartilage and those for the diaphyseal tissue indicate that the anabolic steroid affects both epiphyseal cartilage and diaphysis in the young.