ISSN:
1432-0878
Keywords:
Testis
;
Vas deferens
;
Spermatogenesis
;
Salmo gairdneri
;
Annual cycle
;
Steroidogenesis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary In the maturation cycle of the testis of cultured rainbow trout, three periods can be distinguished: a period of spermatogonial proliferation (June–September), a period of maturation, spermiogenesis and spermiation (September–January), and a period of full spermiation (January–June). In the third period new primary spermatogonia are formed, and old sperm cells are resorbed. Sperm release occurs seldom, if ever in animals kept in captivity. The presence of 3β-HSD, 3α-HSD and G6PD activities, smooth endoplasmic reticulum and mitochondria with tubular cristae indicates steroidogenesis in Leydig cells. These parameters have been found during the annual cycle; the strongest steroidogenic activity is from January to June, when metabolic activities tend to shift to the pentose phosphate shunt. In June, most steroid synthesizing Leydig cells are abundant, at sites where seminiferous tubules contain primary and secondary spermatogonia. In November, a weak steroidogenic activity has also been demonstrated in Sertoli cells lining post-spermatogonial cysts. Other aggregations of steroid synthesizing cells are present outside the testis in the connective tissue surrounding the epithelium of vas deferens. The epithelium of the vas deferens shows positive reaction for 3α-HSD, G6PD, MD, LD and NADHD throughout the testicular cycle; 3α-HSD and G6PD activities are generally weak. Metabolic activity in this epithelium increases when sperm cells are stored in the lumen of the duct (November–June). Acid phosphatase in the epithelium of the vas deferens is more active during the period when sperm cells are resorbed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00225540
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