Open AccessFUNCTIONAL ROLE OF AN ADRENERGIC SPHINCTER IN THE FEMALE URETHRA OF THE GUINEA‐PIG
Author(s) -
Ulmsten Ulf,
Sjöberg NilsOtto,
Alm Per,
Andersson KarlErik,
Owman Christer,
Walles Bengt
Publication year - 1977
Publication title -
acta obstetricia et gynecologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.401
H-Index - 102
eISSN - 1600-0412
pISSN - 0001-6349
DOI - 10.3109/00016347709154998
Subject(s) - urethra , anatomy , medicine , meatus , urethral sphincter , guinea pig , sphincter , adrenergic , plexus , circular muscle , smooth muscle , receptor
. By means of a microtransducer catheter, the urethral pressure profile was recorded in female guinea‐pigs. The maximum urethral pressure averaged 24 mmHg (range 18–27 mmHg) and was found 4 to 7 mm from the vesico‐urethral junction. Fluorescence microscopy of the urethra showed an irregular distribution of fluorescent nerve terminals in the most proximal part of the organ. In a distal direction, there was a continuous increase in the number of adrenergic nerves, with a maximum 4 to 6 mm from the internal meatus, corresponding to the maximum intraurethral pressure point. In this region, a dense plexus of nerves supplied thick muscle coats of smooth muscle, having an outer circular and an inner longitudinal orientation. The findings suggest that a specific region of the female guinea‐pig urethra may serve as an “internal sphincter”.