Abstract
The influence of reserpine treatment upon tension development in the nictitating membrane following sympathetic nerve stimulation and exogenous catecholamine administration has been investigated. lension development in response to nerve stimulation was decreased from 9.68 ± 0.55 g in controls to 1.90 ± 0.22 g in reserpinized preparations indicating a decreased output of mediator.
The effect of autonomic blocking agents was analyzed with regard to elucidating a cholinergic component in the neurally induced response of the nictitating membrane. Phentolamine was virtually ineffective in inhibiting neurally evoked contractions of the reserpinized membrane. This lack of potency contrasted sharply to its marked blocking effect in normal animals. Methylatropine exerted no significant blocking effect on responses to nerve stimulation or catecimolamine in either control or reserpinized preparations. Atropine in the range of 100 µg/kg depressed both neurally aiid catecholamine induced responses in a nonspecific nanner. β-TM-10 and bretylium abolished neurally induced responses in reserpinized animals.
The data do not support the concept that a cholinergic mechanism is involved in sympathetic transmission at the nictitating membrane.
Footnotes
- Received August 16, 1962.
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|
