Testicular growth and hormonal parameters in the male Snell dwarf mouse

Abstract

Abstract. Dwarf mice show delayed testicular growth and their adult testis weights are half the normal value. The aims of the present work were firstly, to compare the developmental profiles of plasma gonadotropins and of testicular cell multiplication and differentiation in dwarf vs normal mice and secondly, to determine the effect of hMG supplementation on dwarf mice. In the dwarf mice no pubertal rise in plasma FSH was observed, and the adult values remained very low when compared with those of normal mice; plasma LH decreased after 40 days of age and remained equal to half the normal values. In adults, testicular testosterone content was greatly increased in dwarf mice compared with normal mice, whereas plasma testosterone and accessory gland weights were reduced. At 24 days of age, the total numbers per testis of Leydig and Sertoli cells were reduced in dwarf vs normal mice, whereas in adult mice their differentiation, but not their total numbers, was reduced. This resulted in lower daily production of leptotene primary spermatocytes and of round spermatids in dwarf than in normal mice. hMG supplementation promoted Leydig and Sertoli cell multiplication, but did not produce full differentiation, resulting in increased daily production of round spermatids. In conclusion, in adult dwarf mice a deficiency in plasma gonadotropins prevents full differentiation of Leydig and Sertoli cells without affecting the number of these cells.

Quantitative and cytological studies of interstitial (Leydig) cells in the scrotal and retained testes of unilateral cryptorchid West African Dwarf goats

“…The deduction from the present observation may be confirmed by the findings of some earlier workers who noted hypertrophy and hyperplasia of interstitial cells of the contralateral scrotal testes and increased quantities of cell organelles such as Golgi apparatus, smooth endoplasmic reticulum and mitochondria (Risbridger et al, 1981;Zaidi et al, 2005). However, the present findings are at variance with the report of Hochereau- de-Reviers et al (1987), who recorded a marked decrease in the total number and size of interstitial cells in the scrotal testes of unilateral cryptorchid rams and pigs. The disparity between the observations in this study and the report of Hochereau- de-Reviers et al (1987) may be attributed to the fact that their findings were from experimentally induced cryptorchid animals, and the data obtained were not quantitatively analyzed.…”

Growth Hormone Advances Spermatogenesis in Premature Rats Treated with Gonadotropin-Releasing Hormone Agonist.

“…5. In GnRHatreated rats, the counts of round spermatids (steps [1][2][3][4][5][6][7][8] were about half that of control rats and those of mature elongated spermatids (steps 15-19) were approximately 20%. Although counts of spermatids in GnRHa + GH-treated rats were also significantly lower than in control rats (p<0.01), those of elongated spermatids (steps 9-19) were significantly In GnRHa+GH-treated rat elongated spermatids were noticeably increased compared with the tubules of GnRHa-treated rat.…”

“…In GnRHa-treated rats, the number of spermatocyte was less than 80% of control rats, and the numbers of round and acrosome phase spermatids (steps [1][2][3][4][5][6][7][8][9][10][11][12][13][14] were approximately 40-50% of controls, and the number of mature spermatids (steps 15-19) were noticeably decreased to less than 20%. In GnRHa+GH-treated rats, the number of spermatocytes was gradually decreased with advancement of stage in spermatogenic cycle from 95% to 85%.…”

“…In GnRHa+GH-treated rats, the number of spermatocytes was gradually decreased with advancement of stage in spermatogenic cycle from 95% to 85%. The numbers of round and acrosome phase spermatids (steps [1][2][3][4][5][6][7][8][9][10][11][12][13][14] were approximately 60% of controls, and the number of mature spermatids were 40-45%. In other words, under the condition of gonadotropin deprivation, loss of germ cells is evident at several stages of development, that is, in mitosis of spermatogonia to spermatocyte, in meiosis of spermatocyte to spermatids and in the stage from acrosome to mature phase of spermatids.…”

“…IT has been suggested by many workers that growth hormone (GH) exerts gonadotropic action in both human and experimental animals [1][2][3][4][5]. Odell and Swerdloff reported that GH facilitated the testicular response to LH and increased the number of LH receptors in premature hypophysectomized rats [6].…”