Endocannabinoids and endovanilloids: a possible balance in the regulation of the testicular GnRH signalling.

Reproductive functions are regulated both at central (brain) and gonadal levels. In this respect, the endocannabinoid system (eCS) has a very influential role. Interestingly, the characterization of eCS has taken many advantages from the usage of animal models different from mammals.

Anandamide regulates the expression of GnRH1, GnRH2, and GnRH-Rs in frog testis.

Gonadotropin-releasing hormone (either GnRH1 or GnRH2) exerts a local activity in vertebrate testis, including human testis. Relationships between endocannabinoid (eCB) and GnRH systems in gonads have never been elucidated in any species so far. To reveal a cross-talk between eCBs and GnRH at testicular level, we characterized the expression of GnRH (GnRH1 and GnRH2) as well as GnRH receptor (GnRH-R1, -R2, and -R3) mRNA in the testis of the anuran amphibian Rana esculenta during the annual sexual cycle; furthermore, the corresponding transcripts were localized inside the testis by in situ hybridization.

UBPy/MSJ-1 system during male germ cell progression in the frog, Rana esculenta.

mUBPy (mouse ubiquitin specific processing protease) is a de-ubiquitinating enzyme expressed in mouse testis and brain. In testis, it interacts with the DnaJ protein MSJ-1 (mouse sperm cell specific DnaJ first homologue), a molecular chaperone expressed in spermatids and spermatozoa. Since MSJ-1 is conserved among vertebrates, to demonstrate an evolutionarily conserved function of UBPy/MSJ-1 system, we assayed mUBPy presence in the anuran amphibian, the frog, Rana esculenta, during the annual sexual cycle.

Endocannabinoid system in frog and rodent testis: type-1 cannabinoid receptor and fatty acid amide hydrolase activity in male germ cells.

N-arachidonoylethanolamide (anandamide [AEA]) is the main endocannabinoid described to date in the testis. It exerts its effects through the activation of G-protein coupled cannabinoid receptors (CNR). However, the activity of AEA in controlling male reproduction is still poorly known.

Fra-1 activity in the frog, Rana esculenta, testis.

Using an anti-Fos family member antiserum, we previously described, in the testis of Rana esculenta, the presence of a nuclear 43-kDa protein that we hypothesized to be Fra-1. Using an antiserum against Fra-1, we here report on Fra-1 expression, localization, and putative activity in the R. esculenta testis during the annual reproductive cycle.

Insulin-induced changes in beta-adrenergic response: an experimental study in the isolated rat papillary muscle.

Background: The aim was to investigate the ability of insulin to modulate the response to beta-adrenergic action on myocardial contractility, assessed as percentage changes of developed tension, in isolated rat papillary muscle.

Methods: Dose-response curves for isoproterenol, calcium, and forskolin were constructed in an incremental fashion with the presence or absence of insulin at the dose of 50 muU/mL. Dose-response curves for isoproterenol on insulin background were also assessed in the presence and absence of a selective antagonist for beta(2)-adrenoceptor, ICI, at the dose of 5 x 10(-8) mol/L.

Fra1 activity in the frog, Rana esculenta, testis: a new potential role in sperm transport.

Using an anti-Fos family member antibody, we have previously described in Rana esculenta testis the presence of a nuclear, 43 kDa protein that we hypothesized to be Fra1. With the assistance of an antibody against Fra1 that does not cross-react with other Fos family members, here we report data on Fra1 expression, localization, and putative activity in Rana esculenta testis during its annual reproductive cycle. Western blot analysis confirms that the nuclear, 43 kDa protein is Fra1.

Detection of msj-1 gene expression in the frog, Rana esculenta testis, brain, and spinal cord.

MSJ-1 is member of the DnaJ/heat shock protein (Hsp) 40 chaperone protein family. It is present in mouse testis and spinal cord. In particular, MSJ-1 is localized in post-meiotic cells and in motoneurones of the ventral horns.