J Clin Endocrinol Metab. 2005 Jun 8; [Epub ahead of print] Related Articles, Links
Leptin secretion by human ejaculated spermatozoa.
Aquila S, Gentile M, Middea E, Catalano S, Morelli C, Pezzi V, Ando S.
Dept. Pharmaco-Biology - Faculty of Pharmacy, Department of Cell Biology, Centro Sanitario - University of Calabria 87030 Arcavacata di Rende (Cosenza) Italy.
INTRODUCTION: Leptin action is a dynamic area of investigation that continues to broaden beyond the basic lipostatic model originally envisaged. Here we show that leptin is expressed in and secreted from human ejaculated spermatozoa. METHODS: By RT-PCR, Western blot and immunofluorescence techniques, we have demonstrated that human sperm express leptin. RIA method evidenced leptin secretion. PI3K/Akt pathway was examined by PI3K activity assay and Western blot. Leptin and insulin regulation of glycogen synthesis was evaluated by glycogen synthase activity (GSA). RESULTS: The large differences of leptin secretion between uncapacitated and capacitated sperm, suggest a functional role for leptin in capacitation. Indeed, in uncapacitated sperm, leptin enhances both cholesterol efflux and protein tyrosine phosphorylation. In uncapacitated sperms, both insulin and leptin increased PI3K activity, Akt S473 and GSK-3 S9 phosphorylation. Interestingly, during capacitation concomitantly to the massive release of both hormones, we observed a strong reduction in the phosphorylation of GSK-3 S9, kinase downstream of Akt that regulates the glycogen synthase. Our results from GSA showed that the enzymatic activity was significantly higher in uncapacitated than in capacitated sperm. Particularly, in uncapacitated sperm GSA appeared to depend on the hormones concentration as the enzymatic activity was stimulated at low doses whereas it was inhibited at high doses. Moreover, both leptin and insulin regulate in autocrine fashion sperm glycogen synthesis. CONCLUSION: Leptin secretion by sperm suggests that the male gamete may be able to modulate its metabolism independently by systemic leptin. These data open new considerations about leptin significance in male fertility.
PMID: 15944217 [PubMed - as supplied by publisher]
"In any contest between power and patience, bet on patience."
~W.B. Prescott
"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
~Albert Einstein
Honey you know how you said you want to lose some weigh.........
Seabiscuit Hogg is a fictious internet character. It is not recommended that you receive medical advice from fictious internet characters.
SBH :)
AAAHHH HAHAHAHA LOL i gotta try that one!!
HD
"SPES ET FIDES"
I may have to send that study to my fiance.
Yeah, be like "hey baby, i heard about this new study......."
HD
"SPES ET FIDES"
Well it ain't workin' for me!"
..."You just have to increase your dosage, hunny...
"In any contest between power and patience, bet on patience."
~W.B. Prescott
"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."
~Albert Einstein
lemme bump up my HCG and see if it helps
Seabiscuit Hogg is a fictious internet character. It is not recommended that you receive medical advice from fictious internet characters.
SBH :)