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O Torgersen

Publications and source records attributed to O Torgersen.

At least 19 recordsLinked to original sources
PubMed1976

Hormones and hormonal target cells in the testis.

Studies over the last few years have greatly increased our knowledge about target cells for sex hormones and gonadotropins in the testis. A diagram illustrating our present state of knowledge is given in Fig. 1. LH is the principle stimulus of testosterone secretion by the Leydig cells. Direct effects of estrogens and androgens on these cells might modulate the response to LH. Androgens are apparently influencing the differentiation and the contractility of peritubular cells. FSH is the principle stimulus for Sertoli cell secretory function before puberty, although androgens are acting synergistically with FSH. After puberty, androgens alone are capable of maintaining on optimal secretory function of the Sertoli cells. In addition to normal secretory activity of the Sertoli cells, direct stimulation of the germ cells by androgens is needed in order maintain spermatogenesis.

Age Factors↗
PubMed1975

Regional distribution of DMBA-induced mammary tumours in the rat.

Since human mammary cancers have a preference for certain regions of the breast, registration of the topography of DMBA-induced mammary tumours in rats was performed. This revealed that most of the tumours occurred in the upper, or thoracic, mammary glands. While the number of tumours in the two abdominal mammary regions was found to be rather constant, the incidence in the two thoracic regions had a tendency to mutual variations. A regional registration should be made in all experiments dealing with induced mammary tumours.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1975

DMBA-induced mammary tumours in locally irradiated rats.

Local X-ray irradiation (400 r) covering 3 abdominal mammary glands revealed no tumours in the irradiated region after 10 months. A similar irradiation 1 or 10 days prior to i.v. DMBA showed a significant increase of tumours in the irradiated region, as compared with the contralateral abdominal region. The two thoracic regions, however, still had a very high tumour incidence. This was equal to, or even higher than that of the irradiated area. The same pattern also prevailed in animals receiving extra-mammary irradiation. The significance of early local factors in carcinogenesis is stressed.

9,10-Dimethyl-1,2-benzanthracene↗