zaprinast and cilostamide

Developmental changes (from 2 to 26 weeks) in phosphodiesterase (PDE) activity in the rat submandibular gland were investigated. Major activities for both cAMP- and cGMP-PDE were present in the 100000 x g supernatant fractions (70-90% of total activities), but not in the pellet fractions, during development. The effects of stimulators (Ca(2+)/calmodulin and cGMP) and inhibitors (cGMP, cilostamide, rolipram and zaprinast) were investigated in the supernatant fractions. During development, PDE4 (cAMP-specific PDE) was a major PDE, indicating that the majority of cAMP is hydrolysed by PDE4. In the young rat, PDE1 hydrolysed cGMP three-fold more than the control, and PDE2 (cGMP-stimulated PDE) was present, indicating that the concentration of intracellular cGMP may be enhanced, and cGMP may function in the growth pathway in the submandibular gland. Chromatograms eluted on a Mono Q HR5/5 ion-exchange column supported the results of the inhibition studies: PDE1, PDE2, PDE3, PDE4 and PDE5 were present in the young submandibular gland, and PDE1, PDE3, PDE4 and PDE5 in the adult gland. Expression of PDE5 was detected by inhibition studies, reverse transcriptase-polymerase chain reaction and Western blotting in the submandibular gland.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; 3',5'-Cyclic-GMP Phosphodiesterases; Animals; Blotting, Western; Calcium; Calmodulin; Cyclic AMP; Cyclic GMP; Cyclic Nucleotide Phosphodiesterases, Type 1; Cyclic Nucleotide Phosphodiesterases, Type 2; Cyclic Nucleotide Phosphodiesterases, Type 3; Cyclic Nucleotide Phosphodiesterases, Type 4; Cyclic Nucleotide Phosphodiesterases, Type 5; Male; Phosphodiesterase Inhibitors; Phosphoric Diester Hydrolases; Purinones; Quinolones; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Rolipram; Submandibular Gland

During each reproductive cycle, a preovulatory surge of gonadotropins induces meiotic maturation of the oocyte in the preovulatory follicle followed by ovulation. Although gonadotropins stimulate cAMP production in somatic cells of the follicle, a decrease in intra-oocyte cAMP levels is required for resumption of meiosis in oocytes. Based on the observed compartmentalization of the cAMP-degrading enzyme, phosphodiesterase, in follicular somatic and germ cells, inhibitors of phosphodiesterase 3 were used to block meiosis in ovulating oocytes in rodents. By this strategy, we demonstrated that fertilization and pregnancy could be prevented without disturbing follicle rupture and normal estrous cyclicity. In contrast to conventional contraceptive pills that disrupt ovarian steroidogenesis and reproductive cycles, the present strategy achieves effective contraception by selective blockage of oocyte maturation and development without alterations in ovulation and reproductive cyclicity.

Topics: 1-Methyl-3-isobutylxanthine; 3',5'-Cyclic-AMP Phosphodiesterases; Animals; Contraceptive Agents, Female; Cyclic AMP; Cyclic Nucleotide Phosphodiesterases, Type 3; Estrus; Female; Fertilization; Heart Rate; Hypoxanthine; Isoenzymes; Meiosis; Menotropins; Mice; Mice, Inbred C57BL; Milrinone; Oogenesis; Ovarian Follicle; Ovulation; Ovulation Induction; Phosphodiesterase Inhibitors; Pregnancy; Purinones; Pyridazines; Pyridones; Pyrrolidinones; Quinolones; Rats; Rats, Sprague-Dawley; Rolipram; Second Messenger Systems; Substrate Specificity; Thiophenes