Effect of human chorionic gonadotrophin on in vitro contractions of stimulated detrusor muscle strips of female rats.
OBJECTIVE
We studied the effect of human chorionic gonadotrophin (hCG) on the in vitro detrusor muscle contractions in female rats.


METHODS
Two adjacent detrusor muscle strips from the bladder dome of 18 female Wistar rats (230-250 gm) were mounted in an organ bath for the recording of isometric tension. Carbachol (10(-9)-10(-3) M), alpha,beta methylene adenosine 5'-triphosphate (ATP) (10(-9)-10(-3) M) and potassium chloride (KCl) (10(-4)-10(-3) M) were applied (n = 6 x 3 groups). Concentration-response curves, before and after the addition of hCG (100 iu/mL) or oxybutynin (10(-5) M) to either muscle strip, were compared.


RESULTS
All curves were displaced to the right by hCG in a concentration-dependent manner with significant inhibition of contractions induced by carbachol (P < 0.001) and KCl (P = 0.016) but not those induced by alpha,beta-methylene ATP (P = 0.4). Estimated order of potency of inhibition was carbachol>KCl>alpha,beta-methylene ATP. The overall inhibitory effect of hCG was significantly less than oxybutynin (P < 0.001).


CONCLUSIONS
hCG significantly inhibited in vitro detrusor contractions induced by depolarization (KCl) and cholinergic (carbachol) but not purinergic (alpha,beta-methylene ATP) stimulation in a dose-dependent manner in female rats.
Department of Obstetrics and Gynecology, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates. rizk.diaa@gmail.com
Diaa E E
DE
Rizk
Nawal A
NA
Osman
Mohammed M
MM
Shafiullah
Nicolaas J D
NJ
Nagelkerke
Mohammed A
MA
Fahim
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D001743:Urinary Bladder / Q000187:drug effects
D006063:Chorionic Gonadotropin; D000244:Adenosine Diphosphate; D011189:Potassium Chloride; D002217:Carbachol