Interstitial Gland

INTERSTITIAL GLAND, otherwise pubertal gland (Steinach), or intermediate, diastematic gland (Ancel and Bouin), groups of cells located between the seminiferous tubules of the testicle; their name is determined in part by topography, in part by the histological character of the formation (some authors attribute to the cells of the I. g. a connective tissue origin, others, on the contrary, an epithelial character), and in part by the significance ascribed to it (see below). Discovered by Leydig (1850), consequently its cells are also called Leydig cells. Cytologically, the I. g. does not always have the same appearance depending on age, nutritional state, phase of sexual life, and species of animal. Ansel and Bouin in 1904 first drew general attention to this gland as a sui generis formation, different from the sperm-producing epithelium. Later, Steinach, based on experiments on rejuvenation, definitely ascribed to it endocrine functions determining the male type, whereas the tubuli seminiferi, in Steinach's opinion, have exclusively a generative significance. The basis for such assertion consists mainly of the following observations. 1. In cryptorchid pigs, the generative part of the testicles detained in the inguinal canal is often found in an atrophic state, whereas the I. g., on the contrary, is not only not atrophic but is even in a state of hyperplasia. Such cryptorchids, being sterile, nevertheless retain the male type. 2. X-ray irradiation of the testicles with a certain intensity of exposure leads to atrophy of the seminiferous tubules, with the preservation, however, of Leydig cells and also with the preservation of the male type. 3. When tying the efferent duct of the testicle, Steinach observed at first similar phenomena, i.e., regression in the generative part of the testicle and, conversely, proliferation of the intermediate cells. The effect is "rejuvenating." Opponents of Steinach's teaching, however, present other arguments. 1. In some species of animals, as for example in the earthworm and some fish, the intermediate gland is not expressed to any appreciable degree; nevertheless, the dependence of secondary sexual characteristics on the sex glands exists. 2. There is not always a correspondence between the intensity of sexual life and the state of the I. g.: thus, in Rana esculenta, the mole, and the pheasant in a state of sexual rest, the I. g. is powerfully developed, whereas in the breeding period, on the contrary, it is weak. 3. The preservation of the sexual type in cryptorchids and under X-ray irradiation of the testicles, some are inclined to explain from the standpoint of the assumption that in such cases at least a small quantity of cellular elements of the seminiferous tubules is preserved, and the eroticizing effect from tying the efferent duct and vasectomy is due to the absorption of a large quantity of products from the degenerating tubules. 4. Precise measurements have shown that as a result of tying the efferent duct in old rats, the I. g. increases only insignificantly, and that at the expense of an increase in the volume of the cells, and not their hyperplasia, which may depend on the overload of these cells with products of breakdown from the generative tubules, etc. Thus the question of the physiological significance of the I. g. cannot yet be considered settled: according to some authors, here the production of male sex hormones takes place, according to others (Stieve, Sternberg, Retterer, Voronov, Simmonds, and others),-waste products from the seminiferous tubules are neutralized or the I. g. serves as an intermediary between the blood vessels and the generative part of the testicle in the sense of nutrition.