Is glandular formation of nitric oxide a prerequisite for muscarinic secretion of fructose in the guinea-pig seminal vesicle?
The significance of nitric oxide (NO) formation in seminal secretion was studied in guinea-pig seminal vesicles. The nitric oxide synthase (NOS) activity was estimated and reduced nicotinamide-adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry was performed. Furthermore, cyclic guanosine 3,5-monophosphate (cGMP) concentration as well as fructose secretion from isolated vesicles was estimated. High Ca2+-dependent NOS activity as well as prominent glandular NADPH-diaphorase staining was found in the secretory epithelium. The NOS inhibitors N(G)-nitro L-arginine methyl ester (L-NAME) and N(G)-nitro L-arginine (L-NNA) inhibited carbachol-induced fructose secretion but the D-isomer to L-NAME had no effect. When L-arginine was administered together with L-NAME, no inhibitory effect on the carbachol-induced fructose secretion could be seen. Nerve-induced fructose secretion was also inhibited by L-NAME. The NO donor glyceryl trinitrate (GTN) increased the fructose secretion. Carbachol or GTN did not increase cGMP levels, nor was fructose secretion inhibited by a guanylate cyclase inhibitor (ODQ). Our results suggests that glandular NO production is a prerequisite for muscarinic fructose secretion in the seminal vesicle via a cGMP-independent pathway.
Ehrén
I
I
Department of Urology, Karolinska Hospital, Stockholm, Sweden.
Sjöstrand
N O
NO
Hammarström
M
M
Wiklund
N P
NP
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D006152:Cyclic GMP / Q000378:metabolism; D005632:Fructose / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000378:metabolism; D006168:Guinea Pigs; D006651:Histocytochemistry; D066298:In Vitro Techniques; D008297:Male; D018721:Muscarinic Agonists / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000378:metabolism*; D012669:Seminal Vesicles / Q000201:enzymology / Q000294:innervation / Q000378:metabolism*
D018721:Muscarinic Agonists; D011976:Receptors, Muscarinic; D005632:Fructose; D009569:Nitric Oxide; D002217:Carbachol; D019001:Nitric Oxide Synthase; D006162:Guanylate Cyclase; D006152:Cyclic GMP