synthetic lhrha or its superactive analogues stimulate gth release. it shows an overlap in the biological activity of lhrha and gnrh in many teleost species. the aim of the present study was to investigate the effects of lhrha2, metoclopramide and chlorpromazine on hpg axis and plasma levels of ght ii. luteinizing hormone releasing hormone analogue 2 (lhrha2) (3 mg/kg) with dopamine antagonis’s...

Plasma immunoreactive t-GTH and androgens, sperm production and biochemical changes in seminal fluid were studied during the spermiation period in rainbow trout. The volume of sperm collected by hand-stripping was very low (< 0.1 ml) at the onset of spermiation, increased slowly during the next 4 weeks and sharply thereafter. Plasma t-GTH was high (6 ng/mi) at the onset and then decreased ; the...

Fractionation and characterization of gonadotropins (GtH) from Fundulus heteroclitus pituitary extracts were carried out using a biocompatible liquid chromatographic procedure (Pharmacia FPLC system). Chromatographic fractions were monitored for gonadotropic activities (induction of oocyte maturation and steroid production) using homologous follicle bioassays in vitro. Size-exclusion chromatogr...

The pituitary gland of Notopterus notopterus (Pallas, 1769) was situated in a shallow pit at the floor of the skull and attached to the infundibulum. On the basis of tinctorial properties the cell types of pituitary were indentified which were distributed in the rostral pars distalis (RPD) proximal pars distalis (PPD) and pars intermedia (PI) in different proportions. The three zones were inner...

An RNA-arbitrarily primed PCR differential display strategy was used to identify candidate genes in the pituitary that are up-regulated by endogenously activated gamma-aminobutyric acid (GABA) systems that may also be involved in the control of reproduction. Goldfish were injected with the GABA metabolism inhibitor gamma-vinyl-GABA (GVG), known for its high efficiency to specifically increase e...