52 research outputs found
Free and conjugated androgen and progestin levels in the serum of stellate sturgeon (Acipenser stellatus Pallas) males treated with female coelomic fluid
Based on the supposition that female coelomic fluid contents have a certain chemical influence on sturgeons, blood serum
concentrations of free and conjugated testosterone (T), 11-ketotestosterone (11KT), 17,20b,21-trihydroxy-4-pregnen-
3-one (20bS), 17,20b-dihydroxy-4-pregnen-3-one (DHP), 11-desoxycortisol (S) and free progesterone (P4) have been measured by radioimmunoassay (RIA) and enzyme-linked
immuno-sorbent assay (ELISA) in stellate sturgeon (Acipenser stellatus Pallas) males treated with female coelomic fluid (CF);
CF steroid levels have also been analyzed. After treatment a significant elevation of free 20bS and glucuronidated DHP and
S levels and the decrease of free T and KT levels have been observed. The obtained data support the idea that the components of CF may play some part in pheromonal effects
for sturgeon reproduction
Free androgens and progestins and their conjugated forms in serum and urine of stellate sturgeon (Acipenser stellatus Pallas) males
Stellate sturgeon (Acipenser stellatus Pallas) males from Volga River treated with LH-RH-A showed an increase of free, sulfated and glucuronided sex steroid levels in serum and urine at spermiation. Conjugated forms of sex steroids could act as pheromones in sturgeon
Levels of free and conjugated androgens and progestins in coelomic fluid and serum of stellate sturgeon (Acipenser stellatus Pallas) females
Stellate sturgeon (Acipenser stellatus Pallas) females from the Volga River were analysed for sex steroids after hormonal stimulation. The results show a significant increase of sulfated sex steroid levels in serum and coelomic fluid (CF) at final maturation (FM). It is hypothesized that the steroid metabolites could be part of a chemical communication system related to reproduction
Tilapia male urinary pheromone stimulates female reproductive axis
Mozambique tilapia males congregate in leks where they establish dominance hierarchies and attract
females to spawn in sandy pits. Dominant males store more urine than subordinates and the pattern
of urination and the high sensitivity of females to male urine suggest chemical signalling via the urine.
Here we show that pre-ovulated and post-spawn females when exposed to dominant male urine
increased significantly, in less than 1 h, the release rate of the maturation-inducing steroid 17,20bdihydroxypregn-
4-en-3-one which is maintained elevated for at least 6 h. This indicates a pheromonal
role for male urine in the synchronisation of spawning. Furthermore, we show that the lack of affinity
of 17,20bP to sex steroid binding globulin explains, at least partly, its rapid release and lack of detection
in the blood. Thus tilapia urine involvement in several communication processes confirms that cichlids
have evolved a sophisticated chemical signalling system together with their complex visual, acoustic
and behavioural displays
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