Studies concerning pineal-gonadal interactions and investigations about the effect of the putative pineal hormone melatonin in male amphibians are very scarce. In this work we investigate the effects of melatonin, synthetic gonadotropin-releasing hormone (GnRH), or both when injected in Rana temporaria males. We conclude that melatonin inhibits spermiation and spermatogonial multiplication when injected alone or with GnRH. We have been unable to find any significant differences in plasma testosterone levels when melatonin or GnRH are injected alone, but when melatonin is injected with GnRH the levels of testosterone are significantly increased. These results seem to demonstrate that melatonin could play a role in the regulation of the gonadal function in the male Rana temporaria.
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http://dx.doi.org/10.1111/j.1600-079x.1988.tb00881.x | DOI Listing |
J Exp Biol
December 2024
Zoological Institute, Technische Universität Braunschweig, Mendelssohnstraße 4, 38106 Braunschweig, Germany.
The interaction of widespread stressors such as nitrate pollution and increasing temperatures associated with climate change is likely to affect aquatic ectotherms such as amphibians. The metamorphic and physiological traits of amphibian larvae during the critical onset of metamorphosis are particularly susceptible to these stressors. We used a crossed experimental design subjecting Rana temporaria larvae to four constant rearing temperatures (18, 22, 26, 28°C) crossed with three environmentally relevant nitrate concentrations (0, 50, 100 mg l-1) to investigate the interactive and individual effects of these stressors on metamorphic (i.
View Article and Find Full Text PDFJ Pept Sci
February 2025
Center of Human Sciences and Humanities, Federal University of ABC, Santo Andre, SP, Brazil.
Antimicrobial peptides (AMPs) are a promising source of new compounds against resistant bacteria. Temporins are a class of AMPs found on the amphibian Rana temporaria and show activity against Gram-positive and Gram-negative bacteria. There are few studies on how these antimicrobials have been used, but new Temporin-F derivatives were engineered with Lys-substitutions to assess the impact of the net charge on antimicrobial activity and toxicity.
View Article and Find Full Text PDFProc Biol Sci
September 2024
Zoological Institute, Technische Universität Braunschweig, Mendelssohnstraße 4, 38106 , Braunschweig, Germany.
Nitrate pollution and global warming are ubiquitous stressors likely to interact and affect the health and survival of wildlife, particularly aquatic ectotherms. Animal health is largely influenced by its microbiome (commensal/symbiotic microorganisms), which responds to such stressors. We used a crossed experimental design including three nitrate levels and five temperature regimes to investigate their interactive and individual effects on an aquatic ectotherm, the European common frog.
View Article and Find Full Text PDFPeerJ
September 2024
Centre for Ecology and Conservation, University of Exeter, Falmouth, United Kingdom.
Chemical pollution, land cover change, and climate change have all been established as important drivers of amphibian reproductive success and phenology. However, little is known about the relative impacts of these anthropogenic stressors, nor how they may interact to alter amphibian population dynamics. Addressing this gap in our knowledge is important, as it allows us to identify and prioritise the most needed conservation actions.
View Article and Find Full Text PDFCryobiology
September 2024
Institute of Cell Biophysics RAS - a Separate Subdivision of Federal Research Centre "Pushchino Scientific Centre for Biological Research RAS", 142290, Moscow oblast, Pushchino, Institutskaya St, 3, Russia.
In recent years, the challenge of preserving amphibian biodiversity has increasingly been addressed through technologies for the short-term storage of unfertilized spawn at low positive temperatures. Previously the possibility of using a 6.5 atm gaseous mixture of carbon monoxide and oxygen for prolonged hypothermic preservation of unfertilized oocytes for more than 4 days was shown.
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