Effect of a somatostatin analogue (SMS 201-995) on tear secretion in rats.
OBJECTIVE
In this study we investigated the effect of a somatostatin analogue, octreotide, (SMS 201-995) on tear secretion in rats.


METHODS
The animals were anaesthetized intraperitoneally (ip) with urethan (1.2 g/kg) The drugs were injected subcutaneously (sc.). Tear samples were collected by folding a 5 mm section of the Schirmer strip over the lower lid margin to absorb tear fluid from the lower conjunctival sac for 5 mm. Forty animals were divided into four groups (n = 10). Group I (control) received 1 ml of saline, group 2 received 100 microg/kg of SMS 201-995, group 3 received 50 microg/kg of acetylcholine (Ach), group 4 received 100 microg/kg of SMS 201-995 and 30 min later 50 microg/kg of Ach. At t = 0 the local anesthetic proparacain HCI was instilled onto the ocular surface to minimize reflex secretion. Baseline secretion was measured before administering the various treatments.


RESULTS
While Ach alone significantly increased tear secretion, SMS 201-995 reduced it compared to saline (control) (p<0.0001, p<0.001, respectively). SMS 201-995 combined with Ach decreased tear secretion compared to Ach alone (p<0.03).


CONCLUSIONS
SMS 201-995 significantly inhibits Ach stimulated tear secretion in rats.
Kapicioğlu
Z
Z
Karadeniz Technical University, School of Medicine, Department of Ophthalmology, Pharmacology, Biochemistry and Public Health, Trabzon, Turkey.
Kalyoncu
I N
IN
Deger
O
O
Can
G
G
D000109:Acetylcholine / Q000008:administration & dosage; D000818:Animals; D007279:Injections, Subcutaneous; D007765:Lacrimal Apparatus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D015282:Octreotide / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013004:Somatostatin / Q000031:analogs & derivatives*; D013268:Stimulation, Chemical; D013666:Tears / Q000187:drug effects / Q000378:metabolism*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage*; D014665:Vasodilator Agents / Q000008:administration & dosage
D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D013004:Somatostatin; D000109:Acetylcholine; D015282:Octreotide