The effect of ovariectomy and oestrogen therapy on the free fatty acid content, endogenous lipase activity, and phospholipid content of the rabbit urinary bladder.
OBJECTIVE
To evaluate the effects of ovariectomy (Ovx) and oestrogen therapy on the free fatty acid (FFA) content, endogenous lipase activity, and the phospholipid (PL) content of the urinary bladder, as reduced circulating oestrogen during and after the menopause has been linked to various bladder dysfunctions including incontinence and recurrent urinary tract infections.


METHODS
In all, 12 New Zealand White female rabbits were separated into three groups; the Ovx + oestrogen group received Ovx and treatment with conjugated beta-oestradiol (3 weeks), the Ovx group received Ovx and vehicle (3 weeks), and the control group received sham operation and vehicle. Cystometry was used to evaluate compliance and in vitro muscle strip studies quantified contractility. For the bulk of the bladder, the muscle and mucosa were separated; FFA and PL concentrations were analysed using standard biochemical techniques.


RESULTS
The bladder contractile responses and compliance decreased after Ovx and returned to or above normal after oestrogen administration. Both FFA and PL concentrations of the mucosa were about three times greater than that of the smooth muscle. Ovx significantly reduced the FFA and PL concentrations of both muscle and mucosa, while oestrogen therapy restored them to normal.


CONCLUSIONS
Reduced FFA and PL content of the smooth muscle membranes would decrease their fluidity and contribute to decreased compliance and contractility. Reduced FFA and PL content of the mucosa would be consistent with mucosal damage and may contribute to the increased incidences of incontinence and bladder infection.
Lin
Wei-Yu
WY
Division of Urology, Chang Gung Memorial Hospital, Chia-Yi, Taiwan.
Radu
Florian
F
Schuler
Catherine
C
Leggett
Robert E
RE
Mannikarottu
Anita
A
Levin
Robert M
RM
D000818:Animals; D004967:Estrogens / Q000627:therapeutic use*; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005260:Female; D008049:Lipase / Q000378:metabolism; D009119:Muscle Contraction / Q000502:physiology; D009130:Muscle, Smooth / Q000503:physiopathology*; D010052:Ovariectomy; D010743:Phospholipids / Q000378:metabolism; D011817:Rabbits; D001743:Urinary Bladder / Q000503:physiopathology*; D014549:Urinary Incontinence / Q000209:etiology; D014552:Urinary Tract Infections / Q000209:etiology
D004967:Estrogens; D005230:Fatty Acids, Nonesterified; D010743:Phospholipids; D008049:Lipase