Objective: While endogenous cannabinoids regulate various physiologic functions, their role in the intestinal tract is unclear. We continuously recorded colonic motility in conscious guinea pigs. Mechanisms of action then were investigated using guinea pig taenia caecum in vitro.
Design: Prospective experimental observations using the cannabinoid agonists 2-arachidonoylglycerol (2-AG) and WIN55212-2; a cannabinoid antagonist, AM281; and ion-channel antagonist.
Setting: University research laboratory.
Subjects: Thirty guinea pigs (20 for in vivo study, 10 for in vitro).
Measurements And Main Results: Colonic motility was monitored in vivo using telemetry via a force transducer attached to the guinea pig taenia caecum. Taenias isolated from other guinea pigs were studied in vitro to assess cannabinoid effects on muscle contractions evoked pharmacologically or electrically. Immediately after cannabinoid injection in conscious guinea pigs, taenial relaxation began peaking at 30 to 40 min. In animals pretreated with AM281, a CB1 cannabinoid receptor antagonist, cannabinoid evoked relaxation was less evident. In vitro, cannabinoids suppressed KCl-induced taenial contractions; this suppression was opposed by charybdotoxin, a Ca(2+)-activated K(+)-channel inhibitor, but not AM281. Cannabinoids decreased amplitude of repeated contractions evoked by electrical stimulation (an effect inhibited by AM281) but not muscle tension.
Conclusions: Cannabinoids decreased intestinal tract tension in vivo, apparently via central CB1 receptors. This differs from peristaltic suppression.
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http://dx.doi.org/10.1272/jnms.72.43 | DOI Listing |
J Vis Exp
January 2025
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University;
Cough is one of the most common symptoms of many respiratory diseases. Chronic cough significantly impacts quality of life and imposes a considerable economic burden. Increased cough sensitivity is a pathophysiological hallmark of chronic cough.
View Article and Find Full Text PDFInt J Nanomedicine
January 2025
College of Animal Science, Guizhou University, Guiyang, Guizhou, People's Republic of China.
Background: Adjusting thickening agent proportions in nanoemulsion gel (NG) balances its transdermal and topical delivery properties, making it more effective for dermatophytosis treatment.
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Vet Rec
January 2025
Department of Animal and Agriculture, Hartpury University, Gloucester, UK.
Background: There is limited research on how rodent owners use and perceive veterinary services and what the demand for pet insurance for these species is.
Methods: An online survey of owners of pet rodents (guinea pigs, hamsters, rats, gerbils and mice) measured owner confidence in recognising signs of illness, their opinions on and use of veterinary services and their willingness to purchase pet insurance.
Results: A total of 1700 respondents completed the survey.
Int J Antimicrob Agents
January 2025
School of Pharmacy, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, China. Electronic address:
The prevalence of herpes simplex virus type 1 (HSV-1) infection and the emergence of drug-resistant HSV-1 strains posts a significant global health challenge, necessitating the urgent development of effective anti-HSV-1 drugs. As one of the most prevalent molecular chaperones, heat shock protein 90 α (Hsp90α) has been extensively demonstrated to regulate a range of viral infections, thus representing a promising antiviral target. In this study, we identified JD-13 as a novel Hsp90α inhibitor and explored its capability in inhibiting HSV-1 infection.
View Article and Find Full Text PDFBiomed Pharmacother
January 2025
Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, USA.
An understanding of intracellular mechanisms by which fentanyl and other synthetic opioids exert adverse effects on breathing is needed. Using freely moving adult male guinea pigs, we administered the nitric oxide synthase (NOS) inhibitor, L-NAME (N-nitro-L-arginine methyl ester), to determine whether nitrosyl factors, such as nitric oxide and S-nitrosothiols, play a role in fentanyl-induced respiratory depression. Ventilatory parameters were recorded by whole body plethysmography to determine the effects of fentanyl (75 μg/kg, IV) in guinea pigs that had received a prior injection of vehicle (saline), L-NAME or the inactive D-isomer, D-NAME (both at 50 μmol/kg, IV), 15 min beforehand.
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