Role of connexin 43 in the maintenance of spontaneous activity in the guinea pig prostate gland.
OBJECTIVE
To investigate the role of connexin 43 in the maintenance of spontaneous activity in prostate tissue from young and old guinea pigs.


METHODS
Conventional intracellular microelectrode and tension recording techniques, coupled with Western blot analysis and immunohistochemistry for connexin 43 (CX43) were used. The effects of three gap junction uncouplers, 18β glycyrrhetinic acid (10 µM, 40 µM), carbenoxolone (10 µM, 50 µM) and octanol (0.5 mM, 1 mM), were studied in cells displaying slow wave activity and on spontaneously contracting tissue from prostate glands of young (2-5 months) and old (9-16 months) guinea pigs.


RESULTS
18β Glycyrrhetinic acid (40 µM), carbenoxolone (50 µM) or octanol (0.5 mM) abolished slow wave activity in prostate tissue from young and old guinea pigs and depolarized membrane potential by approximately 5 mV. These treatments also abolished all contractions in both sets of prostate tissue. These effects were reversed upon washout. Western blot analysis and CX43 immunohistochemistry showed that there was no age-related difference in the expression and distribution of CX43 in prostate tissues.


CONCLUSIONS
When gap junctional communication via CX43 was disrupted, spontaneous activity was abolished at a cellular and whole tissue level; CX43 is therefore essential for the maintenance of spontaneous slow wave activity and subsequent contractile activity in the guinea pig prostate gland.
Dey
Anupa
A
Medicinal Chemistry & Drug Action, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia.
Kusljic
Snezana
S
Lang
Richard J
RJ
Exintaris
Betty
B
D000367:Age Factors; D000818:Animals; D002229:Carbenoxolone / Q000494:pharmacology; D018031:Connexin 43 / Q000378:metabolism / Q000502:physiology*; D017629:Gap Junctions / Q000187:drug effects; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D000442:Octanols / Q000494:pharmacology; D011467:Prostate / Q000187:drug effects / Q000502:physiology*
D018031:Connexin 43; D000442:Octanols; C119129:18alpha-glycyrrhetinic acid; D002229:Carbenoxolone; D006034:Glycyrrhetinic Acid