Showing papers in "General and Comparative Endocrinology in 1985"

TL;DR: Results indicate that the thyroid plays a role in flounder meetamorphosis comparable to its well-known developmental role in amphibian metamorphosis.

TL;DR: The results indicate that there is an increased interrenal responsiveness to stress during the period of smoltification in coho salmon.

TL;DR: The presence of TBPA in all vertebrates suggests prealbumin to be a far more important thyroxine carrier than earlier anticipated.

TL;DR: Concentrations of testosterone (T), 11-ketotestosterone (11-KT) and 17 alpha-hydroxy-20 beta-dihydroprogesterone (17 alpha 20 beta P) were measured by a direct radioimmunoassay technique in the plasma of male rainbow trout from two winter- spawning strains and one autumn-spawning strain.

TL;DR: High levels of aromatase in the neuroendocrine tissues of teleosts recommend them as animal models for further studying the enzyme, its regulation, and its role in governing androgen-dependent responses in central targets.

TL;DR: Findings are consistent with the suggestion that 17 alpha, 20 beta-diOHprog is involved in the process of spermiation in teleosts and suggested that this hormone is a testicular steroidal mediator of gonadotrophin-induced spermation in amago salmon.

TL;DR: The hypothesis that in this amphibian, exposure to acute stress or to exogenous corticosterone can suppress plasma androgen titers by inhibiting the release of LH-RH from the hypothalamus is supported.

TL;DR: The profile in plasma FSH is consistent with the view that this gonadotropin may regulate androgen secretion but it did not show the expected relationship to the spermatogenetic cycle.

TL;DR: It is suggested that GH or synergistic action of GH and T4 plays an important role in seawater adaptation during smoltification of amago salmon.

TL;DR: Although the seasonal trend of increasing androgen corresponded with the start of intense chorusing by the population, behavior of individuals and their circulating androgen levels did not correlate.

TL;DR: It was concluded that dopamine does not effect the GTH release directly, but modulates the effect of endogenous and exogenous gonadotrophin-releasing hormone.

TL;DR: The results indicate that handling and confinement only activated the corticotrophs of the pars distalis, not the melanotrophS of the neurointermediate lobe, whereas when combined with a thermal shock, both cell types were activated.

TL;DR: D-Ala6 or (imBzl)-D-His6 substitutions of [Trp7, Leu8, Pro9-NEt]-LHRH are not superactive in goldfish, whereas the D-Arg6 substitution is highly superactive, indicating that there are differences in the factors that make salmon and mammalian GnRH superactive.

TL;DR: The hormonal correlates of female-like copulatory behavior suggest that, as in other vertebrates, female receptivity is activated by a synergism of estradiol and progesterone.

TL;DR: The presence of separate IGF I and IGF II peptides in chickens and turtles but only IGF I in amphibians and fish is recorded, indicating that the gene duplication giving rise to two separate IGFs arose before reptilian evolution.

TL;DR: The salmon liver estrogen receptor system has many features in common with typical estradiol receptors from other vertebrates and appears to be the richest source of hepatic estrogen receptor so far found for any vitellogenic species.

TL;DR: When autumn-spawning bitterling, Acheilognathus rhombea were held under a constant short photoperiod at 25 degrees during their natural breeding season, the females spawned regularly at intervals of about 5 days, and physiological stages passed through three distinct physiological stages: vitellogenesis, maturation, and spawning.

TL;DR: A highly specific radioimmunoassay for the measurement of prolactin (PRL) in the plasma and pituitary of salmonid fishes was developed using a rabbit antiserum to chinook salmon (Oncorhynchus tschawytscha) PRL and showed exactly the same competitive inhibition curves in the RIA, regardless of iodination of either hormone.

TL;DR: Like plasma steroid profiles, there were coordinated changes in plasma triiodothyronine and thyroxine levels in males and females through the prespawning season and there was a slight increase in plasma insulin during the terminal maturation of the lampreys.

TL;DR: Methyl testosterone and 17β-estradiol were administered intraperitoneally to nonvitellogenic rainbow trout and E2 significantly reduced plasma triiodo-l-thyronine levels and thyroid epithelial cell height (TEH), but had no apparent effect on plasma l-thyroxine (T4) levels.

TL;DR: Y-organs from intact donors, those from de-eyestalked crabs exhibit greatly increased cholesterol uptake and secretion of both ecdysone and 4-min unknown in vitro, which was determined not to be ponasterone A, inokosterone, makisterone, or several other possible products or intermediates.

TL;DR: There is a seasonal variation in responsiveness to injection of pimozide, LRH-A and the combination of pimzide plus LRH -A, and these seasonal changes may be due to differences in the pituitary content of GtH, the ability of the pituitsary to synthesize GTH, or changes in Gth cell receptors for GnRH and dopamine.

TL;DR: The highest amounts of melatonin were found in the eyes, duodenum, and the pineal so that extrapinealmelatonin exceeded pineal melatonin, indicating that the immunoreactivity was due to endogenous melatonin in pigeon tissues.

TL;DR: Results demonstrate that nutritional stimuli are involved in the regulation of thyroid function in birds, particularly in the peripheral generation of T3.

TL;DR: In vivo experiments have demonstrated that the formation of the endocytic complex is controlled by juvenile hormone from the corpora allata, and this developmental event was blocked by ablation of corporas allata at eclosion, but it was restored by either implantation of corporaAllata into allatectomized female or the application of juvenile hormone III.

TL;DR: Although cortisol levels showed large variations, they appeared to be stimulated by the priming dose of pituitary extract, and it is suggested that this, rather than 17,20 beta P, may be the natural inducer of maturation in carp.

TL;DR: It appears that the males must be sexually active in order for physiological changes to occur, as males that failed to engage in courtship behavior with a spawning pair had GtH and milt values not different from isolated fish, which suggests that male sexual behavior and elevations in milt are concurrent events that share a common activation pathway in the brain.

TL;DR: T3 is the principle metabolically active thyroid hormone in the chicken and the reduction in heat production at 40 degrees is related to the decline in T3, suggesting that the response to a stressor need not involve increased adrenocortical activity.

TL;DR: Green turtles do not exhibit the "postnuptial" type of testis cycle typical of many temperate-zone turtles, and the levels of plasma androgen may be important for initiating and maintaining sex behavior, although they are not tightly linked during the mating season.

TL;DR: The results of this study suggest that the steroid environment is a critical factor in the response of the Mullerian ducts to MIS, and that estrogen blockage may allow endogenous MIS from the ovary to induce partial regression of the Münchhausen ducts in the female chick embryo.