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Outflow facility in the monkey eye: effects of calcitonin gene-related peptide, cholecystokinin, galanin, substance P and capsaicin

Almegard, B and Andersson, Sven LU (1990) In Experimental Eye Research 51(6). p.685-689
Abstract
A study in cats has shown that intracameral injection of calcitonin gene-related peptide (CGRP) increases the outflow facility by four- to fivefold concomitant with a decrease in intra-ocular pressure (IOP). Since there are great differences in the anatomy of the aqueous outflow routes between cats and primates, we have examined the effects of CGRP in the cynomolgus monkey. The possible influence of the sensory neuropeptides cholecystokinin (CCK), galanin and substance P on the outflow facility and IOP were also investigated. Determinations were performed using a two-level constant-pressure procedure. At 40–60 min after intracameral injection of 3 μg CGRP the outflow facility was increased from 0·68±0·11 to 1·03±0·15 μl min−1 mmHg−1 in the... (More)
A study in cats has shown that intracameral injection of calcitonin gene-related peptide (CGRP) increases the outflow facility by four- to fivefold concomitant with a decrease in intra-ocular pressure (IOP). Since there are great differences in the anatomy of the aqueous outflow routes between cats and primates, we have examined the effects of CGRP in the cynomolgus monkey. The possible influence of the sensory neuropeptides cholecystokinin (CCK), galanin and substance P on the outflow facility and IOP were also investigated. Determinations were performed using a two-level constant-pressure procedure. At 40–60 min after intracameral injection of 3 μg CGRP the outflow facility was increased from 0·68±0·11 to 1·03±0·15 μl min−1 mmHg−1 in the CGRP-treated eyes, and from 0·71±0·12 to 0·79±0·10 μl min−1 mmHg−1 in the control eyes. The mean difference in increase was 0·27±0·06 μl min−1 mmHg−1 (P < 0·01, N = 7). During the experiments there was a small rise in the IOP. CGRP at a dose of 3 μg caused a small rise in aqueous humor protein concentration. An attempt to release endogenous CGRP with capsaicin did not result in an increased outflow facility. Three micrograms each of CCK, galanin and substance P had no significant effect on either the outflow facility or the IOP. A miosis was observed in the experiments with CCK in agreement with previous findings. CCK seems thus to cause contraction of the pupillary sphincter but does not influence the ciliary muscle sufficiently to cause a facility effect in the monkey eye. Our results indicate that the effect of CGRP on the outflow facility in the monkey eye is much smaller than in cats, and that the other sensory neuropeptides tested have no clear effects on the conductance of the outflow routes. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
calcitonin gene-related peptide, capsaicin, cholecystokinin, galanin, intraocular pressure, outflow facility, substance P
in
Experimental Eye Research
volume
51
issue
6
pages
685 - 689
publisher
Elsevier
external identifiers
  • pmid:1702389
  • scopus:0025677472
ISSN
0014-4835
DOI
10.1016/0014-4835(90)90053-W
language
English
LU publication?
yes
id
45c6d64d-0a60-492e-b031-6eb2b19a8c45 (old id 1105583)
date added to LUP
2008-08-06 08:37:16
date last changed
2017-07-30 03:40:33
@article{45c6d64d-0a60-492e-b031-6eb2b19a8c45,
  abstract     = {A study in cats has shown that intracameral injection of calcitonin gene-related peptide (CGRP) increases the outflow facility by four- to fivefold concomitant with a decrease in intra-ocular pressure (IOP). Since there are great differences in the anatomy of the aqueous outflow routes between cats and primates, we have examined the effects of CGRP in the cynomolgus monkey. The possible influence of the sensory neuropeptides cholecystokinin (CCK), galanin and substance P on the outflow facility and IOP were also investigated. Determinations were performed using a two-level constant-pressure procedure. At 40–60 min after intracameral injection of 3 μg CGRP the outflow facility was increased from 0·68±0·11 to 1·03±0·15 μl min−1 mmHg−1 in the CGRP-treated eyes, and from 0·71±0·12 to 0·79±0·10 μl min−1 mmHg−1 in the control eyes. The mean difference in increase was 0·27±0·06 μl min−1 mmHg−1 (P &lt; 0·01, N = 7). During the experiments there was a small rise in the IOP. CGRP at a dose of 3 μg caused a small rise in aqueous humor protein concentration. An attempt to release endogenous CGRP with capsaicin did not result in an increased outflow facility. Three micrograms each of CCK, galanin and substance P had no significant effect on either the outflow facility or the IOP. A miosis was observed in the experiments with CCK in agreement with previous findings. CCK seems thus to cause contraction of the pupillary sphincter but does not influence the ciliary muscle sufficiently to cause a facility effect in the monkey eye. Our results indicate that the effect of CGRP on the outflow facility in the monkey eye is much smaller than in cats, and that the other sensory neuropeptides tested have no clear effects on the conductance of the outflow routes.},
  author       = {Almegard, B and Andersson, Sven},
  issn         = {0014-4835},
  keyword      = {calcitonin gene-related peptide,capsaicin,cholecystokinin,galanin,intraocular pressure,outflow facility,substance P},
  language     = {eng},
  number       = {6},
  pages        = {685--689},
  publisher    = {Elsevier},
  series       = {Experimental Eye Research},
  title        = {Outflow facility in the monkey eye: effects of calcitonin gene-related peptide, cholecystokinin, galanin, substance P and capsaicin},
  url          = {http://dx.doi.org/10.1016/0014-4835(90)90053-W},
  volume       = {51},
  year         = {1990},
}