Volker Bluem

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The androgen receptor (AR) was localized immunohistochemically after different hormonal treatments in the ventral prostate, coagulating gland, seminal vesicle and epididymis of the adult rat. In the untreated controls AR-immunoreactivity was confined to the cell nuclei. One week after castration or treatment with the gonadotropin-releasing hormone(More)
This report seeks to extend the existing information on the relationship of regulatory neuropeptides to neuroendocrine and pituitary function through a longitudinal study of the distribution of FMRF-amide, galanin (GAL), and neurotensin (NT) in the brain and pituitary gland of three species of Xiphophorus from birth to sexual maturity. In the pituitary(More)
Testicular tissue collected at different stages of gonadal development was incubated with a pituitary extract (PE) from mature salmon. Three androgens (11-ketotestosterone, OT; 11 beta-hydroxytestosterone, OHT; and testosterone, T) and 17 alpha,20 beta-dihydroxyprogesterone (17-20 beta P) were quantified by radioimmunoassay in incubation media. OHT and OT(More)
Rana esculenta (L.), kept under natural conditions, show almost constant body weights in the annual cycle. Fat body weight, however, has a distinct maximum in October decreasing continuously to a May minimum which is also evident in the fat body index. The triglyceride and protein contents show the same course. Surprizingly high amounts of glycogen are(More)
Blood cells of male and female rainbow trout showed 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) activity in vitro, reducing 11 beta-hydroxyandrostenedione and 11-ketoandrostenedione (OA) to 11 beta-hydroxytestosterone and 11-ketotestosterone (OT), respectively. Enzyme activity did not vary with gonadal development in either sex. The conversion of(More)
The closed equilibrated biological aquatic system (C.E.B.A.S) is a man-made aquatic ecosystem which consists of four subcomponents: an aquatic animal habitat, an aquatic plant bioreactor, an ammonia oxidizing bacteria filter and a data acquisition/control unit. It is a precursor for different types of fish and aquatic plant production sites which are(More)
Immunoreactive (ir) lamprey (l), mammalian (m), chicken II (chII), and salmon (s) gonadotropin-releasing hormone (GnRH) and ir-coho salmon beta-gonadotropins I and II (GTH I and GTH II) have been localized in the brain and pituitary gland of Xiphophorus maculatus, the platyfish, at various stages of development from birth to sexual maturity. Ir-GTH I was(More)
Antisera raised against steroid hormones [estradiol-17 beta (E2), testosterone (T), 11 beta-hydroxyandrostenedione (OHA)] were used to localize immunoreactive material in fixed and paraffin-embedded pituitaries of the African catfish and the rainbow trout. Organic extracts of pituitary homogenates were analyzed for steroid hormones by radioimmunoassay and(More)
1. The secretion of five androgens was quantified from trout testes under GTH-stimulation in vitro before and after the onset of milt production, and a general increase of basal and GTH stimulated androgen secretion was recorded during this period. 2. 11-Ketotestosterone, testosterone, and in spermiating males, 11 beta-hydroxytestosterone as well showed GTH(More)