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Title	Regulation of prostaglandin synthesis in the rat seminal vescicle, and the effects of prostaglandins on its contractility
Author	Powers, Robert Edgar
Date	1981
Extent	vii, 83 leaves : ill. ; 29 cm
Subject.MeSH	Prostaglandins -- biosynthesis Seminal Vesicles -- physiology Academic Dissertations
Collection	MUSC Theses and Dissertations
Contributing Institution	Waring Historical Library (MUSC)
Digitization Specifications	CanoScan 8400, Archival files are tiffs.
Date Digital	2015
Rights	Copyright is held by the author.
Language	English
SC County	Charleston County (S.C.)
Type	Text
Format	application/pdf
Media Type	Manuscripts
Resource Identifier	mtd1981_powers_re
Abstract	This project was designed to test the hypothesis that prostaglandins are produced in the rat seminal vesicle (RSV) in response to coition, and that these prostaglandins act to modulate the motility of the RSV. These contractions may aid in the expulsion of vesicular fluid from the RSV in the process of seminal emission. Copulatory activity in the rat resulted in significant increases in the prostaglandin E (PGE) (p<O.05), prostaglandin F (PGF) (p <0.05), and 6-keto-PGF la (6-kF) (p<O.02) levels in the tissues of the RSV as measured by specific radioimmunoassay. Epinephrine (3.75 x 10^-7 M and 3 x 10^-6 M) increased the levels of PGE and PGF in both the tissues and media of in vitro incubations of RSV at 5 minutes (p 0.05). This stimUlation was antagonized by phentolamine (3 x 10^-5 M), an alpha-adrenergic blocking agent, in vitro. No stimUlation was observed in incubations at 30 or 60 minutes. Carbamylcholine (2 x 10^6 M), a stable analogue of acetylcholine, had no effect on the RSV prostaglandin synthesis at five minutes. Additionally, neither bradykinin (1 x 10^-6 M) nor oxytocin (1 x 10^-4 M) afiected prostaglandin levels in media from the in vitro incubations. Norepinephrine, epinephrine, carbamylcholine and bradykinin all increased the tonus of the RSV as measured by longitudinal contraction in the isolated RSV preparation. The response to epinephrine was antagonized by phentolamine, an alpha-adrenergic blocking agent, but not by propranolol, a betaiii adrenergic blocker. The response to carbamylcholine was antagonized by atropine, a muscarinic cholinergic blocker. Several prostaglandins caused a dose-dependent increase in the RSV tonus in the isolated RSV preparation. The potency of the prostaglandins tested (in terms of the dose required to produce a tonus response equal to the half-maximal PGE2 response) was: PGE2 > PGF2 > PGI2 > 6-kF. The stable prostaglandin endoperoxide analogue, U-44069, had no effect on RSV tonus. The contractile response to POE was antagonized by atropine and by SC-19220, a competitive inhibitor of PGE action in a number of tissues. Phentolamine (3 x 10-6 M) totally blocks the epinephrine-induced tonus increase, but was without effect on the PGE induced response. These results suggest that during mating, catecholamines released in response to sympathetic activity stimulate the biosynthesis of prostaglandins in the RSV. This stimulation, which is mediated by alpha-adrenergic receptors, may be an important physiological regulator of prostaglandin synthesis in vivo. We postulate that the prostaglandins which are synthesized in the tissue are mediators of two separate effects on the RSV: (1) feedback regulation of the release and action of norepinephrine from the sympathetic neurons in the tissues, and (2) stimulation of contractility of the RSV by an alpha-adrenergic independent, atropine-sensitive mechanism which may involve the mediation of the parasympathetic nervous system associated with the RSV.

Regulation of prostaglandin synthesis in the rat seminal vescicle, and the effects of prostaglandins on its contractility

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