Effect of a somatostatin analogue (SMS 201-995) on tear secretion in rats

• Published in: International ophthalmology Vol. 22; no. 1; pp. 43 - 45
• Main Authors: Kapicioğlu, Z, Kalyoncu, I N, Deger, O, Can, G
• Format: Journal Article
• Language: English
• Published: Netherlands 1998
• Subjects: Acetylcholine - administration & dosage; Animals; Injections, Subcutaneous; Lacrimal Apparatus - drug effects; Lacrimal Apparatus - secretion; Male; Octreotide - administration & dosage; Rats; Rats, Sprague-Dawley; Somatostatin - analogs & derivatives; Stimulation, Chemical; Tears - drug effects; Tears - secretion; Vasoconstrictor Agents - administration & dosage; Vasodilator Agents - administration & dosage
• ISSN: 0165-5701
• DOI: 10.1023/A:1006171323980

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