Gallbladder motility and the sex of the guinea pig

Gall Bladder Stones Formation in Patients with Breast Cancer on Tamoxifen Therapy in Iraqi Female

BACKGROUND: Tamoxifen has an estrogenic effect on the liver, lead to increase the danger of gallstone development. AIM: This study aimed to determine the prevalence of gall bladder stones formation during tamoxifen therapy. METHODS: A prospective casecontrol study enrolled 14 premenopausal and 36 postmenopausal females. The gall bladder condition was assessed by abdominal ultrasound using “Alpinion Portable Color Doppler E-CUBE,” in addition, clinical parameters collected as age and weight of patients. RESULTS: Approximately, 14 (28%) of women were premenopausal their age ranged from (25 to 44) years, and 36 (72%) postmenopausal females their age was between (45 and 78) years. The duration of tamoxifen therapy was (range >–72) months, with 33 control cases. All cases examined by pelvic ultrasound, only 11 (22%) showed gall bladder stones. The gall bladder stones were diagnosed, in 4 of premenopausal, whereas seven patients were postmenopausal. There is a significant relation with gall bladder stones with increase body weight during therapy. CONCLUSION: There is a significant correlation between gall bladder stones formation and tamoxifen therapy. Postmenopausal women have a higher risk of developing gall bladder stones formation.

The Flavone Luteolin, an Endocrine Disruptor, Relaxed Male Guinea Pig Gallbladder Strips

Background

Luteolin (3',4',5,7-tetrahydroxyflavone) is a flavone with a yellow crystalline appearance present in numerous plants such as broccoli, green chili, and carrot. Luteolin is considered to be an endocrine disruptor with potent estrogen agonist activity and potent progesterone antagonist activity. Luteolin has effects on smooth muscle. Luteolin relaxed guinea pig trachea smooth muscle as it inhibited both phosphodiesterase and reduced intracellular Ca²⁺. Luteolin also caused vasorelaxation in rat thoracic aorta smooth muscle by inhibiting intracellular Ca²⁺ release, inhibition of sarcolemmal Ca²⁺ channels, and activation of K⁺ channels. Luteolin or its glycosides from artichoke extracts may have an ameliorating effect on irritable bowel syndrome. The purpose of this study was to determine if luteolin had an effect on gallbladder motility.

Methods

An in vitro pharmacologic technique was utilized. Either cholecystokinin octapeptide (CCK) or KCl were used to induce tension in male guinea pig gallbladder strips maintained in Sawyer-Bartlestone chambers. Luteolin relaxed either the CCK- or KCl-induced tension in a concentration dependent manner. Various blockers were added to the chambers to determine which second messenger system(s) mediated the observed relaxation. Paired t-tests were used for statistical analysis. Differences between mean values of P < 0.05 were considered significant.

Results

Treatment of the gallbladder strips with luteolin prior to either KCl or CCK significantly (P < 0.001) decreased the amount of either KCl- or cholecystokinin-induced tension. The 2-aminoethoxydiphenylborane was used to ascertain if the release of intracellular Ca²⁺ mediated the luteolin-induced relaxation. It significantly (P < 0.001) decreased the amount of luteolin-induced relaxation. To ascertain if PKA mediated the luteolin-induced relaxation, PKA inhibitor 14-22 amide myristolated was used. It significantly (P < 0.01) reduced the amount of luteolin-induced relaxation. Neither KT5823, N^G-methyl-L-arginine acetate salt, genistein, tetraethylammonium, nor fulvestrant had a significant effect. To ascertain if PKC mediated the luteolin-induced relaxation, the PKC inhibitors bisindolymaleimide IV and chelerythrine Cl^- were used together. They had no significant effect.

Conclusions

Luteolin relaxed cholecystokinin- or KCl-induced tension by blocking extracellular Ca²⁺ entry as well as intracellular Ca²⁺ release. In addition, the actions of PKA are also involved in mediating the luteolin effect.

Estradiol mediates relaxation of porcine lower esophageal sphincter

Most pregnant women have symptoms of gastroesophageal reflux disease (GERD) during pregnancy. Postmenopausal hormone replacement therapy is associated with GERD. The effects of estradiol on lower esophageal sphincter (LES) motility and GERD are not clearly known. The purpose of this study is to investigate the effects of estradiol on the motility of the porcine LES. Relaxations of clasp and sling strips of porcine LES caused by estradiol were measured using isometric transducers. We investigated the mechanism of estradiol-induced relaxation of the porcine LES using tetraethylammonium, apamine, iberiotoxin, glibenclamide, KT5720, KT5823, NG-nitro-l-arginine, tetrodotoxin, and ω-conotoxin GVIA. Reverse transcription polymerase chain reaction (PCR) analysis and immunohistochemistry (IHC) were performed to determine the existence of the G protein-coupled estrogen receptor (GPER) in the porcine LES. In endothelin-1-precontracted porcine LES strips, estradiol caused marked relaxations in a concentration-dependent manner. The mechanism of estradiol-induced relaxation on the porcine LES was associated with the potassium channel. Reverse transcription PCR analysis and IHC revealed that GPER was expressed in the sling and clasp fibers of the porcine LES. This finding suggests that GPER mediates the relaxation of the porcine LES. Estradiol may play a role in LES motility.

Gallbladder motility and the sex of the guinea pig

Progesterone (P), 17β‐estradiol (E2), and dihydrotestosterone (DHT) affect gallbladder motility. When gallbladders were taken from women and men, women had more estrogen and P receptors than men. Both P and E2 had an inhibitory effect upon gallbladder contractility in men and premenopausal and postmenopausal women. Similar findings have been reported in gallbladder strips from male and female guinea pigs. In the present study, there was no significant difference in the amount of E2‐, P‐, or DHT‐induced relaxation of CCK‐induced tension when the responses in gallbladder strips from male and female guinea pigs were compared. Three metabolites of P were used: 17‐hydroxyprogesterone (17‐P), 20α‐hydroxyprogesterone (20‐P), and 21‐hydroxyprogesterone (21‐P). There was no significant difference in the responses from strips from male and female guinea pigs. In order to determine if the effects of E2 and P were additive, strips from male animals were exposed to either E2 or P and the amount of relaxation recorded. After recovery, the strips were exposed to E2 or P in reverse order to ensure the order of treatment had no effect. Then, the strips were treated with both E2 and P simultaneously and the relaxation recorded. This procedure was repeated with strips from female guinea pigs. The effect of E2 and P was found to be additive; however, the response of the strips from each sex were not significantly different. It is concluded that the sex of the guinea pig has no significant effect on the response to the sex hormones used.