AUTONOMIC CONTROL OF SOME POTENTIAL TARGETS OF THE UROPHYSIS IN ADVANCED TELEOSTS
THIAN WOON CHUON
THIAN WOON CHUON
Citations
Altmetric:
Alternative Title
Abstract
In vitro, cholinergic agonists caused contractions of
the bladder of 0. mossambicus; and the gonads and rectum
(both circular and longitudinal muscles) of 0, rnossambicus
and C. auratus. These actions were blocked by atropine,
suggesting that the muscles in these organs are under
excitatory control of post-ganglionic parasympathetic
(cholinergic) neurons.
There is pharmacological evidence that at least some of
these post-ganglionic parasympathetic neurons were located
on the wall of the bladder of 0. mossambicus, in the gonads
of 0. mossambicus and C.auratus and the rectal smooth muscle
of 0. mossambicus and C. auratus , being under the control
of a cholinergic preganglionic input. Catecholamines were
inhibitory in the bladder, ovary and rectal longitudinal
muscle, typically acting via beta adrenoceptors. In the case
of the testis and rectal circular muscles, on the other
hand, catecholamines stimulate contractions through acting
on alpha receptors.
Arginine vasotocin caused contractions of the bladder,
the gonads and the rectal muscles of 0. rnossambicus. These
tissues were much less sensitive to arginine vasopressin and
oxytocin, Urophys ia 1 extracts failed to induced any
responses in the bladder of 0. mossambi cus and the gonads
and rectal muscles of 0. mossambicus and C. auratus,
suggesting that urophysial hormones are not involved in
regulating any function that might have been attributed to
the contraction of these organs.
Destruction of the urophysis in pregnant female P.
reticulata did not interfere with subsequent parturition,
suggesting that the mother's urophysis does not play an
important role in regulating birth.
Keywords
Source Title
Publisher
Series/Report No.
Collections
Rights
Date
1988
DOI
Type
Thesis