1
|
Ou G, Komura A, Hojo M, Kato R, Ikeda M, Fujisawa M, Xu K, Yoshioka K, Obara K, Tanaka Y. Pharmacological study on the enhancing effects of U46619 on guinea pig urinary bladder smooth muscle contraction induced by acetylcholine and α,β-methylene ATP and the possible involvement of protein kinase C. J Pharmacol Sci 2023; 153:119-129. [PMID: 37770153 DOI: 10.1016/j.jphs.2023.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/18/2023] [Accepted: 08/28/2023] [Indexed: 10/03/2023] Open
Abstract
We examined whether U46619 (a prostanoid TP receptor agonist) could enhance the contractions of guinea pig urinary bladder smooth muscle (UBSM) in response to acetylcholine (ACh) and an ATP analog (α,β-methylene ATP (αβ-MeATP)) through stimulation of the UBSM TP receptor and whether protein kinase C (PKC) is involved. U46619 (10-7 M) markedly enhanced UBSM contractions induced by electrical field stimulation and ACh/αβ-MeATP (3 × 10-6 M each), the potentiation of which was completely suppressed by SQ 29,548 (a TP receptor antagonist, 6 × 10-7 M). PKC inhibitors did not attenuate the ACh-induced contractions enhanced by U46619 although they partly suppressed the U46619-enhanced, αβ-MeATP-induced contractions. While phorbol 12-myristate 13-acetate (PMA, a PKC activator, 10-6 M) did not enhance ACh-induced contractions, it enhanced αβ-MeATP-induced contractions, an effect that was completely suppressed by PKC inhibitors. αβ-MeATP-induced contractions, both with and without U46619 enhancement, were strongly inhibited by diltiazem. U46619/PMA enhanced 50 mM KCl-induced contractions, the potentiation of which was partly/completely attenuated by PKC inhibitors. These findings suggest that U46619 potentiates parasympathetic nerve-associated UBSM contractions by stimulating UBSM TP receptors. PKC-increased Ca2+ influx through voltage-dependent Ca2+ channels may partially play a role in purinergic receptor-mediated UBSM contractions enhanced by TP receptor stimulation.
Collapse
Affiliation(s)
- Guanghan Ou
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
| | - Akane Komura
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
| | - Misaki Hojo
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
| | - Rina Kato
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
| | - Masahiro Ikeda
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
| | - Miki Fujisawa
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
| | - Keyue Xu
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
| | - Kento Yoshioka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
| | - Keisuke Obara
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan.
| | - Yoshio Tanaka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
| |
Collapse
|
2
|
Obara K, Kaneko M, Yamashita M, Liu G, Yoshioka K, Tanaka Y. Platelet-activating factor (PAF) enhances guinea pig detrusor smooth muscle contractile activities by stimulating voltage-dependent Ca 2+ channels and store-operated Ca 2+ channels. J Pharmacol Sci 2023; 152:123-127. [PMID: 37169476 DOI: 10.1016/j.jphs.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/14/2023] [Accepted: 04/11/2023] [Indexed: 05/13/2023] Open
Abstract
We investigated the extracellular Ca2+ influx pathways involved in platelet-activating factor (PAF)-enhanced guinea pig detrusor smooth muscle (DSM) contractile activities. One micromolar PAF-enhanced DSM contractile activities were completely inhibited by extracellular Ca2+ removal and strongly suppressed by voltage-dependent Ca2+ channel (VDCC) inhibitors. PAF-enhanced DSM contractile activities remaining in the presence of verapamil (10 μM) were not inhibited by LOE-908 (30 μM, an inhibitor of receptor-operated Ca2+ channels (ROCCs)), but were almost completely inhibited by SKF-96365 (30 μM, an inhibitor of store-operated Ca2+ channels (SOCCs) and ROCCs). These results suggest that VDCCs and SOCCs are responsible for PAF-enhanced DSM contractile activities.
Collapse
Affiliation(s)
- Keisuke Obara
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi-City, Chiba 274-8510, Japan.
| | - Mizuki Kaneko
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi-City, Chiba 274-8510, Japan
| | - Mio Yamashita
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi-City, Chiba 274-8510, Japan
| | - Ge Liu
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi-City, Chiba 274-8510, Japan
| | - Kento Yoshioka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi-City, Chiba 274-8510, Japan
| | - Yoshio Tanaka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi-City, Chiba 274-8510, Japan
| |
Collapse
|
3
|
Liu G, Obara K, Yoshioka K, Tanaka Y. Pharmacological Studies on the Ca 2+ Influx Pathways in Platelet-Activating Factor (PAF)-Induced Mouse Urinary Bladder Smooth Muscle Contraction. Biol Pharm Bull 2023; 46:997-1003. [PMID: 37394649 DOI: 10.1248/bpb.b22-00923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Platelet-activating factor (PAF) not only acts as a mediator of platelet aggregation, inflammation, and allergy responses but also as a constrictor of various smooth muscle (SM) tissues, including gastrointestinal, tracheal/bronchial, and pregnancy uterine SMs. Previously, we reported that PAF induces basal tension increase (BTI) and oscillatory contraction (OC) in mouse urinary bladder SM (UBSM). In this study, we examined the Ca2+ influx pathways involved in PAF-induced BTI and OC in the mouse UBSM. PAF (10-6 M) induced BTI and OC in mouse UBSM. However, the PAF-induced BTI and OC were completely suppressed by extracellular Ca2+ removal. PAF-induced BTI and OC frequencies were markedly suppressed by voltage-dependent Ca2+ channel (VDCC) inhibitors (verapamil (10-5 M), diltiazem (10-5 M), and nifedipine (10-7 M)). However, these VDCC inhibitors had a minor effect on the PAF-induced OC amplitude. The PAF-induced OC amplitude in the presence of verapamil (10-5 M) was strongly suppressed by SKF-96365 (3 × 10-5 M), an inhibitor of receptor-operated Ca2+ channel (ROCC) and store-operated Ca2+ channel (SOCC), but not by LOE-908 (3 × 10-5 M) (an inhibitor of ROCC). Overall, PAF-induced BTI and OC in mouse UBSM depend on Ca2+ influx and the main Ca2+ influx pathways in PAF-induced BTI and OC may be VDCC and SOCC. Of note, VDCC may be involved in PAF-induced BTI and OC frequency, and SOCC might be involved in PAF-induced OC amplitude.
Collapse
Affiliation(s)
- Ge Liu
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Keisuke Obara
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Kento Yoshioka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Yoshio Tanaka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| |
Collapse
|
4
|
Liu G, Kaneko M, Yoshioka K, Obara K, Tanaka Y. Platelet-activating factor (PAF) strongly enhances contractile mechanical activities in guinea pig and mouse urinary bladder. Sci Rep 2022; 12:2783. [PMID: 35177680 PMCID: PMC8854422 DOI: 10.1038/s41598-022-06535-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 01/31/2022] [Indexed: 11/09/2022] Open
Abstract
In this study, we investigated the effects of platelet-activating factor (PAF) on the basal tone and spontaneous contractile activities of guinea pig (GP) and mouse urinary bladder (UB) smooth muscle (UBSM) tissues to determine whether PAF could induce UBSM tissue contraction. In addition, we examined the mRNA expression of the PAF receptor, PAF-synthesizing enzyme (lysophosphatidylcholine acyltransferase, LPCAT), and PAF-degrading enzyme (PAF acetylhydrolase, PAF-AH) in GP and mouse UB tissues using RT-qPCR. PAF (10-9-10-6 M) strongly enhanced the basal tone and spontaneous contractile activities (amplitude and frequency) of GP and mouse UBSM tissues in a concentration-dependent manner. The enhancing effects of PAF (10-6 M) on both GP and mouse UBSM contractile activities were strongly suppressed by pretreatment with apafant (a PAF receptor antagonist, GP: 10-5 M; mouse: 3 × 10-5 M). The PAF receptor (Ptafr), LPCAT (Lpcat1, Lpcat2), and PAF-AH (Pafah1b3, Pafah2) mRNAs were detected in GP and mouse UB tissues. These findings reveal that PAF strongly enhances the contractile mechanical activities of UBSM tissues through its receptor and suggest that the PAF-synthesizing and -degrading system exists in UBSM tissues. PAF may serve as both an endogenous UBSM constrictor and an endogenous mediator leading to detrusor overactivity.
Collapse
Affiliation(s)
- Ge Liu
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Mizuki Kaneko
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Kento Yoshioka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Keisuke Obara
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan.
| | - Yoshio Tanaka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| |
Collapse
|