| Abstrakt: |
The present study reports the presence of progesterone, testosterone and 17β-estradiol and their corresponding binding proteins in the reproductive system ofOctopus vulgarisLam (phylum Mollusca, subphylum Cephalopoda). These sex hormones occur in testis, vas deferens, seminal vesicle, prostate and Needham's sac. The hemolymph also contains a small, but significant, amount of these hormones and their carrier proteins. Among various tissues of the reproductive system, the seminal vesicle possesses the highest concentration of progesterone (4.8 ng/g tissue). The testis is the organ which contains the highest amount of testosterone (5.2 ng/g) whereas the prostate is the organ which contains the highest amount of 17β-estradiol (0.92 ng/g). The presence of these hormones has been ascertained by a radioimmunoassay method, an immunoenzymatic method and by a chemical (HPLC) method. Scatchard studies indicated that vas deferens and seminal vesicle contain specific sex steroid binding molecules at affinity levels comparable to those of vertebrate steroid receptors (0.5–5.0 pmol/g protein). In addition to the presence of the hormones, the delta 5,3 βhydroxysteroid dehydrogenase, the key enzyme of steroidogenesis, also is found in testis. From a phylogenetic point of view, these findings are very interesting because they indicate a common origin of a sex hormonal system between Mollusca Cephalopoda and Vertebrates. |
Full Text from ScienceDirect