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. Here we provide direct evidence on the presence of the "endocannabinoid system," constituted by type-1 cannabinoid receptor (CNR1) and fatty acid amide hydrolase (FAAH), in the frog Rana esculenta testis demonstrating its expression in tubular compartment. In fact, during the annual reproductive cycle, both proteins increase in September, when the appearance of spermatids (SPT) occurs. Immunocytochemistry confirms their localization in germ cells and, in particular, in elongated SPT. Signals are still present in spermatozoa (SPZ), as demonstrated by Western blot analysis. Furthermore, the activation of CNR1 reduces sperm motility. Comparative research, carried out using mouse and rat SPZ, definitely indicates that the endocannabinoid system operates in SPZ of phylogenetically distant species. A conserved physiological role of endocannabinoid system in controlling the inhibition of sperm motility is suggested.
Cobellis
Gilda
G
Dipartimento di Medicina Sperimentale, Sez. F. Bottazzi, II Università di Napoli, 80138 Napoli, Italy.
Cacciola
Giovanna
G
Scarpa
Donatella
D
Meccariello
Rosaria
R
Chianese
Rosanna
R
Franzoni
Maria Fosca
MF
Mackie
Ken
K
Pierantoni
Riccardo
R
Fasano
Silvia
S
D000581:Amidohydrolases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D005075:Biological Evolution; D063385:Cannabinoid Receptor Modulators / Q000378:metabolism*; D063388:Endocannabinoids; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D051379:Mice; D053284:Polyunsaturated Alkamides; D011893:Rana esculenta; D051381:Rats; D017207:Rats, Sprague-Dawley; D043882:Receptors, Cannabinoid / Q000235:genetics / Q000378:metabolism*; D013094:Spermatozoa / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D013737:Testis / Q000378:metabolism; D000099252:Fatty Acid Amide Hydrolases
D000581:Amidohydrolases; D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D004791:Enzyme Inhibitors; D053284:Polyunsaturated Alkamides; D043882:Receptors, Cannabinoid; D000099252:Fatty Acid Amide Hydrolases; C078814:anandamide; C107594:N-(4-hydroxyphenyl)arachidonylamide